WorldWideScience

Sample records for jsc time-modulated ultra-wideband

  1. Ultra-Wideband Radio

    Directory of Open Access Journals (Sweden)

    Won Namgoong

    2005-03-01

    Full Text Available The application of ultra-wideband (UWB technology to low-cost short-range communications presents unique challenges to the communications engineer. The impact of the US FCC's regulations and the characteristics of the low-power UWB propagation channels are explored, and their effects on UWB hardware design are illustrated. This tutorial introduction includes references to more detailed explorations of the subject.

  2. Ultra-Wideband Transceiver for Integrated Communication and Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to develop an innovative way of using Time Modulated Ultra Wideband (TM-UWB) transceivers (radios) to provide high performance integrated...

  3. Hemispheric ultra-wideband antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2006-04-01

    This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

  4. Introduction to Ultra Wideband for Wireless Communications

    DEFF Research Database (Denmark)

    Nikookar, Homayoun; Prasad, Ramjee

    wireless channels, interference, signal processing as well as applications and standardization activities are addressed. Introduction to Ultra Wideband for Wireless Communications provides easy-to-understand material to (graduate) students and researchers working in the field of commercial UWB wireless......Ultra Wideband (UWB) Technology is the cutting edge technology for wireless communications with a wide range of applications. In Introduction to Ultra Wideband for Wireless Communications UWB principles and technologies for wireless communications are explained clearly. Key issues such as UWB...... communications. Due to tutorial nature of the book it can also be adopted as a textbook on the subject in the Telecommunications Engineering curriculum. Problems at the end of each chapter extend the reader's understanding of the subject. Introduction to Ultra Wideband for Wireless Communications will aslo...

  5. Ultra wideband antennas design, methodologies, and performance

    CERN Document Server

    Galvan-Tejada, Giselle M; Jardón Aguilar, Hildeberto

    2015-01-01

    Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book:Discusses the developed theory for UWB antennas in frequency and time domainsDelivers a brief exposition of numerical methods for electromagnetics oriented to antennasDescribes solid-planar equivalen

  6. Ultra-wideband radar sensors and networks

    Science.gov (United States)

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  7. Ultra-Wideband Radio Frequency Identification Systems

    CERN Document Server

    Nekoogar, Faranak

    2012-01-01

    Ultra-Wideband Radio Frequency Identification Systems describes the essentials of radio frequency identification systems as well as their target markets. The authors provide a study of commercially available RFID systems and characterizes their performance in terms of read range and reliability in the presence of conductive and dielectric materials. The capabilities and limitations of some commercial RFID systems are reported followed by comprehensive discussions of the advantages and challenges of using ultra-wideband technology for tag/reader communications. The book presents practical aspects of UWB RFID system such as: pulse generation, remote powering, tag and reader antenna design, as well as special applications of  UWB RFIDs in a simple and easy-to-understand language.

  8. Ultra-Wideband, Short Pulse Electromagnetics 9

    CERN Document Server

    Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9

    2010-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...

  9. Human Target Tracking in Multistatic Ultra-Wideband Radar

    NARCIS (Netherlands)

    He, Y.

    2014-01-01

    Multistatic ultra-wideband radar is acknowledged to be useful for human tracking in indoor surveillance. In this thesis, a global signal processing chain for detection and localization of moving human targets using a multistatic ultra-wideband radar system is proposed. The design options for the sys

  10. Ultra wideband technology for wireless sensor networks

    Science.gov (United States)

    Wang, Yue; Xiong, Weiming

    2011-08-01

    Wireless sensor networks (WSNs) have emerged as an important method for planetary surface exploration. To investigate the optimized wireless technology for WSNs, we summarized the key requirements of WSNs and justified ultra wideband (UWB) technology by comparing with other competitive wireless technologies. We also analyzed network topologies as well as physical and MAC layer designs of IEEE 802.15.4a standard, which adopted impulse radio UWB (IR-UWB) technology. Our analysis showed that IR-UWB-based 802.15.4a standard could enable robust communication, precise ranging, and heterogeneous networking for WSNs applications. The result of our present work implies that UWB-based WSNs can be applied to future planetary surface exploration.

  11. Ultra-Wideband Transceivers for Cochlear Implants

    Directory of Open Access Journals (Sweden)

    Reisenzahn Alexander

    2005-01-01

    Full Text Available Ultra-wideband (UWB radio offers low power consumption, low power spectral density, high immunity against interference, and other benefits, not only for consumer electronics, but also for medical devices. A cochlear implant (CI is an electronic hearing apparatus, requiring a wireless link through human tissue. In this paper we propose an UWB link for a data rate of Mbps and a propagation distance up to 500 mm. Transmitters with step recovery diode and transistor pulse generators are proposed. Two types of antennas and their filter characteristics in the UWB spectrum will be discussed. An ultra-low-power back tunnel diode receiver prototype is described and compared with conventional detector receivers.

  12. Parametric estimation of ultra wideband radar targets

    Institute of Scientific and Technical Information of China (English)

    Fan Ping; Jing Zhanrong

    2009-01-01

    Based on the analysis of impulse response properties, a scattering model of ultra wideband (UWB) radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple signal classification (MUSIC), and matrix pencil (MP), are introduced to calculate the scattering center parame-ters of targets and their performances are compared. The simulation experiments show that there are no differ-ences in the estimation precision of MUSIC and MP methods when the signal-to-noise ratio (SNR) is larger than 13 dB. However, the MP method has a better performance than that of MUSIC method when the SNR is smaller than 13 dB. Besides, the time consuming of MP method is leas than that of MUSIC method. Therefore, the MP algorithm is preferred for the parametric estimation of UWB radar targets.

  13. Ultra wideband wireless body area networks

    CERN Document Server

    Thotahewa, Kasun Maduranga Silva; Yuce, Mehmet Rasit

    2014-01-01

    This book explores the design of ultra wideband (UWB) technology for wireless body-area networks (WBAN).  The authors describe a novel implementation of WBAN sensor nodes that use UWB for data transmission and narrow band for data reception, enabling low power sensor nodes, with high data rate capability.  The discussion also includes power efficient, medium access control (MAC) protocol design for UWB based WBAN applications and the authors present a MAC protocol in which a guaranteed delivery mechanism is utilized to transfer data with high priority.  Readers will also benefit from this book’s feasibility analysis of the UWB technology for human implant applications through the study of electromagnetic and thermal power absorption of human tissue that is exposed to UWB signals.   • Describes hardware platform development for IR-UWB based WBAN communication; • Discusses power efficient medium access control (MAC) protocol design for IR-UWB based WBAN applications; • Includes feasibility analy...

  14. Apparatus And Method For Wireless Monitoring Using Ultra-wideband Frequencies

    KAUST Repository

    Sana, Furrukh

    2015-04-23

    A system for and a method of wirelessly monitoring one or more patients can include transmitting ultra-wideband pulses toward the one or more patients, receiving ultra-wideband signals, and sampling the ultra-wideband signals. Sampling the ultra-wideband pulses can be performed with a sample rate that is less than the Nyquist rate. Impulse response can be estimated and/or recovered by exploiting sparsity of the impulse response.

  15. An Analog Correlator for Ultra-Wideband Receivers

    Directory of Open Access Journals (Sweden)

    Tu Chunjiang

    2005-01-01

    Full Text Available We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to . As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to , which is sufficient for detection by the comparator. The circuit dissipates about from double voltage supplies of and using SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.

  16. Conical Shape Antenna with Circular Slots for Ultra Wideband Applications

    Directory of Open Access Journals (Sweden)

    Ahmed H. Al-Shaheen

    2012-01-01

    Full Text Available In this paper an ultra wideband of conical shaped with different configurations are designed and simulated.The antenna is printed on FR4 dielectric substrate of dimensions 42mm X 42 mm X 1.5 mm.conical shape using as a stub with circular slot etched on the ground plane, with microstrip CPW fed. The results shows a good bandwidth impedance below (S11< -10 dB for the ultra wideband UWB range from 3.1-10.6 GHz. Parametric study is done to optimize these antennas to be fit with UWB wireless applications.

  17. Ultra-wideband MMICs for remote sensing applications

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2003-01-01

    This paper presents an overview of the current activity at the Technical University of Denmark in the field of ultra-wideband monolitic microwave integrated circuits (MMICs) for next-generation high-resolution synthetic aperature radar (SAR) systems. The transfer function requirements for MMIC co...

  18. Ultra-Wideband Signals for Target Detection in Foliage

    Science.gov (United States)

    2007-11-02

    1997], and Fourier analysis [ Papoulis , 1987]. This approach gives a simple intuitive physical explanation for the formation and propagation of...transform or Fast Fourier Transform (FFT) techniques can be applied to compute (2.14) and (2.15) [ Papoulis , 1987; Oppenheim et al., 1997] to obtain the...Assessment of Ultra-Wideband (UWB) Technology, Battelle Tactical Technology Center, July 13, 1990. A. Papoulis , The Fourier Integral and its

  19. Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

    Directory of Open Access Journals (Sweden)

    J. Jilkova

    2008-04-01

    Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

  20. An Ultra-Wideband Millimeter-Wave Phased Array

    Science.gov (United States)

    Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

    2016-01-01

    Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

  1. An Ultra-Wideband Schottky Diode Based Envelope Detector for 2.5 Gbps signals

    DEFF Research Database (Denmark)

    Cimoli, Bruno; Valdecasa, Guillermo Silva; Granja, Angel Blanco

    2016-01-01

    In this paper an ultra-wideband (UWB) Schottky diode based envelope detector is reported. The detector consists of an input matching network, a Schottky diode and wideband output filtering network. The output network is tailored to demodulate ultra-wideband amplitude shift keying (ASK) signals up...

  2. Ultra-wideband and 60 GHz communications for biomedical applications

    CERN Document Server

    Yuce, Mehmet R

    2013-01-01

    This book investigates the design of devices, systems, and circuits for medical applications using the two recently established frequency bands: ultra-wideband (3.1-10.6 GHz) and 60 GHz ISM band. These two bands provide the largest bandwidths available for communication technologies and present many attractive opportunities for medical applications. The applications of these bands in healthcare are wireless body area network (WBAN), medical imaging, biomedical sensing, wearable and implantable devices, fast medical device connectivity, video data transmission, and vital signs monitoring. The r

  3. UCom: Ultra-wideband Communications in Harsh Propagation Environments

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, F

    2007-03-14

    LLNL has developed an ultra-wideband (UWB) system that provides unique, through-the-wall wireless communications in heavy metallic and heavy concrete indoor channels. LLNL's UWB system is the only available wireless communications system that performs successfully and reliably in facilities where conventional narrowband communications usually fail due to destructive reflections from multiple surfaces. These environments include: cargo ships and reinforced, heavy concrete buildings. LLNL's revolutionary system has applications for the military, as well as commercial indoor communications in multistory buildings, and cluttered industrial structures.

  4. Ultra-wideband reflective polarization converter based on anisotropic metasurface

    Science.gov (United States)

    Wu, Jia-Liang; Lin, Bao-Qin; Da, Xin-Yu

    2016-08-01

    In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x- or y-polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471387, 61271250, and 61571460).

  5. Integrated Ultra-Wideband Tracking and Carbon Dioxide Sensing System Design for International Space Station Applications

    Science.gov (United States)

    Ni, Jianjun (David); Hafermalz, David; Dusl, John; Barton, Rick; Wagner, Ray; Ngo, Phong

    2015-01-01

    A three-dimensional (3D) Ultra-Wideband (UWB) Time-of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide (CO2) and felt upset. Recent findings indicate that frequent, short-term crew exposure to elevated CO2 levels combined with other physiological impacts of microgravity may lead to a number of detrimental effects, including loss of vision. To evaluate the risks associated with transient elevated CO2 levels and design effective countermeasures, doctors must have access to frequent CO2 measurements in the immediate vicinity of individual crew members along with simultaneous measurements of their location in the space environment. To achieve this goal, a small, low-power, wearable system that integrates an accurate CO2 sensor with an ultra-wideband (UWB) radio capable of real-time location estimation and data communication is proposed. This system would be worn by crew members or mounted on a free-flyer and would automatically gather and transmit sampled sensor data tagged with real-time, high-resolution location information. Under the current proposed effort, a breadboard prototype of such a system has been developed. Although the initial effort is targeted to CO2 monitoring, the concept is applicable to other types of sensors. For the initial effort, a micro-controller is leveraged to integrate a low-power CO2 sensor with a commercially available UWB radio system with ranging capability. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested

  6. Optically addressed ultra-wideband phased antenna array

    Science.gov (United States)

    Bai, Jian

    Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of ultra-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled oscillators (VCO) cannot provide a tunable range of several octaves, distribution of wideband local oscillator signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides ultra-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an ultra-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization

  7. Micro-Doppler processing for ultra-wideband radar data

    Science.gov (United States)

    Smith, Graeme E.; Ahmad, Fauzia; Amin, Moeness G.

    2012-06-01

    In this paper, we describe an operational pulse Doppler radar imaging system for indoor target localization and classification, and show how a target's micro-Doppler signature (μDS) can be processed when ultra-wideband (UWB) waveforms are employed. Unlike narrowband radars where time-frequency signal representations can be applied to reveal the target time-Doppler frequency signatures, the UWB system permits joint range-time-frequency representation (JRTFR). JRTFR outputs the data in a 3D domain representing range, frequency, and time, allowing both the μDS and high range resolution (HRR) signatures to be observed. We delineate the relationship between the μDS and the HRR signature, showing how they would form a complimentary joint feature for classification. We use real-data to demonstrate the effectiveness of the UWB pulse-Doppler radar, combined with nonstationary signal analyses, in gaining valuable insights into human positioning and motions.

  8. Macro-motion detection using ultra-wideband impulse radar.

    Science.gov (United States)

    Xin Li; Dengyu Qiao; Ye Li

    2014-01-01

    Radar has the advantage of being able to detect hidden individuals, which can be used in homeland security, disaster rescue, and healthcare monitoring-related applications. Human macro-motion detection using ultra-wideband impulse radar is studied in this paper. First, a frequency domain analysis is carried out to show that the macro-motion yields a bandpass signal in slow-time. Second, the FTFW (fast-time frequency windowing), which has the advantage of avoiding the measuring range reduction, and the HLF (high-pass linear-phase filter), which can preserve the motion signal effectively, are proposed to preprocess the radar echo. Last, a threshold decision method, based on the energy detector structure, is presented.

  9. Low sampling frequency processing for ultra-wideband signals

    Science.gov (United States)

    Wan, Yonglun; Si, Qiang; Lu, Youxin; Wang, Hong; Wang, Xuegang

    2005-11-01

    Ultra-wideband (UWB) signals are widely used in radar, navigation and satellite communications. It is rather difficult to process UWB signals. In this paper we adopt dechirp pulse compression method to process the received UWB linear frequency modulated (LFM) signals. UWB signals are converted into signals with frequency components that are proportional to the relative range between the target and the reference target. It means to select low-speed analog-to-digital converters (ADC) for sampling UWB signals. The simulation results show that LFM signal with 600MHz center frequency, 200MHz bandwidth and 30usec pulse width can be processed under 70MHz sampling frequency by means of the method.

  10. Ultra-wideband noise radar based on optical waveform generation

    Science.gov (United States)

    Grodensky, Daniel; Kravitz, Daniel; Zadok, Avi

    2012-06-01

    A microwave-photonic, ultra-wideband (UWB) noise radar system is proposed and demonstrated. The system brings together photonic generation of UWB waveforms and fiber-optic distribution. The use of UWB noise provides high ranging resolution and better immunity to interception and jamming. Distribution over fibers allows for the separation the radar-operating personnel and equipment from the location of the front-end. The noise waveforms are generated using the amplified spontaneous emission that is associated with stimulated Brillouin scattering in a standard optical fiber, or with an erbium-doped fiber amplifier. Our experiments demonstrate a proof of concept for an integrated radar system, driven by optically generated UWB noise waveforms of more than 1 GHz bandwidth that are distributed over 10 km distance. The detection of concealed metallic object and the resolving of two targets with the anticipated ranging resolution are reported.

  11. Ultra wideband reflector antenna log-periodic feed with operating frequency range 1–20 GHz.

    Directory of Open Access Journals (Sweden)

    F. F. Dubrovka

    2010-05-01

    Full Text Available Results of modeling and optimization of electric characteristics of ultra wideband reflector antenna log-periodic feed, based on two log-periodic antennas array for operating over frequency range 1 -20 GHz, are presented.

  12. Ultra-wideband Radar Methods and Techniques of Medical Sensing and Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, C N; Chang, J T; Romero, C E; Watson, J; Pearce, F J; Levin, N

    2005-10-07

    Ultra-wideband radar holds great promise for a variety of medical applications. We have demonstrated the feasibility of using ultra-wideband sensors for detection of internal injuries, monitoring of respiratory and cardiac functions, and continuous non-contact imaging of the human body. Sensors are low-power, portable, and do not require physical contact with the patient. They are ideal for use by emergency responders to make rapid diagnosis and triage decisions. In the hospital, vital signs monitoring and imaging application could improve patient outcomes. In this paper we present an overview of ultra-wideband radar technology, discuss key design tradeoffs, and give examples of ongoing research in applying ultra-wideband technology to the medical field.

  13. Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR)

    Science.gov (United States)

    2013-06-01

    performance in complex scenarios. Among these scenarios are ground penetrating radar and forward-looking radar for landmine and improvised explosive...Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) by Traian Dogaru ARL-TN-0548 June 2013...2013 Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) Traian Dogaru Sensors and Electron

  14. Ultra-Wideband Harmonic Radar for Locating Radio-Frequency Electronics

    Science.gov (United States)

    2015-03-01

    Ultra-Wideband Harmonic Radar for Locating Radio- Frequency Electronics by Gregory J Mazzaro, Kyle A Gallagher, Albert R Owens, Kelly D...Department of the Army position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an...Research Laboratory Adelphi, MD 20783-1138 ARL-TR-7256 March 2015 Ultra-Wideband Harmonic Radar for Locating Radio- Frequency Electronics

  15. Design and Performance Evaluation on Ultra-Wideband Time-Of-Arrival 3D Tracking System

    Science.gov (United States)

    Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Dusl, John

    2012-01-01

    A three-dimensional (3D) Ultra-Wideband (UWB) Time--of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide and felt upset. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested in the Wireless Habitat Testbed which simulates the ISS module environment. In this presentation, we discuss the 3D TOA tracking algorithm and the performance evaluation based on different tracking baseline configurations. The simulation results show that two configurations of the tracking baseline are feasible. With 100 picoseconds standard deviation (STD) of TOA estimates, the average tracking error 0.2392 feet (about 7 centimeters) can be achieved for configuration Twisted Rectangle while the average tracking error 0.9183 feet (about 28 centimeters) can be achieved for configuration Slightly-Twisted Top Rectangle . The tracking accuracy can be further improved with the improvement of the STD of TOA estimates. With 10 picoseconds STD of TOA estimates, the average tracking error 0.0239 feet (less than 1 centimeter) can be achieved for configuration "Twisted Rectangle".

  16. Design of Analytical Model for Ultra Wideband System

    Directory of Open Access Journals (Sweden)

    Alpana P. Adsul

    2010-05-01

    Full Text Available The UWB (Ultra Wideband technology has drawn phenomenal interest in industry as well as academia.Ultra Wide Band impulse radios are microwave systems that communicate using baseband pulses of veryshort duration. UWB systems transmit information data over a wide frequency spectrum with low powerconsumption and high speed for local area wireless network applications. Unlike the traditional digitalcommunication method based on a carrier wave, UWB is pulse based. Pulse Generation, modulation, andmultiple access are time domain dependent functions. This paper presents the development of analyticalmodel for UWB system. A theoretical reference for UWB system performances is designed in non-idealchannels. In this mathematical models for biphase, pulse–position and hybrid modulation are developed.The detection rules are formulated for detecting signals in AWGN channels. The performance of UWBsystem is described with the help of BER. The BER of a UWB system depends on the modulation schemeand detection method it uses. It is observed that for optimum performance modulation parameterselection is important.

  17. Time-Domain Diversity in Ultra-Wideband MIMO Communications

    Directory of Open Access Journals (Sweden)

    Alain Sibille

    2005-03-01

    Full Text Available The development of ultra-wideband (UWB communications is impeded by the drastic transmitted power limitations imposed by regulation authorities due to the “polluting” character of these radio emissions with respect to existing services. Technical solutions must be researched in order either to limit the level of spectral pollution by UWB devices or to increase their reception sensitivity. In the present work, we consider pulse-based modulations and investigate time-domain multiple-input multiple-output (MIMO diversity as one such possible solution. The basic principles of time-domain diversity in the extreme (low multipath density or intermediate (dense multipath UWB regimes are addressed, which predict the possibility of a MIMO gain equal to the product Nt×Nr of the numbers of transmit/receive antenna elements when the channel is not too severe. This analysis is confirmed by simulations using a parametric empirical stochastic double-directional channel model. They confirm the potential interest of MIMO approaches solutions in order to bring a valuable performance gain in UWB communications.

  18. Cross-layer optimization in ultra wideband networks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ultra wideband (UWB) network brings both chance and challenge to personal area wireless communications. Compared with other IEEE 802 small range wireless protocols (such as WLAN and Bluetooth), UWB has both extremely high bandwidth (up to 480 Mbps) and low radiation. Moreover, the structured MAC layer of UWB is the fundamental difference to WLAN. The top one is that only when two UWB devices belong to the same piconet can they communicate with each other directly, which means that we must jointly consider topology formation and routing when deploying UWB networks because the interaction between routing and topology formation makes separate optimization ineffective. This paper tries to optimize UWB network from a cross-layer point of view. Specifically, given device spatial distribution and traffic requirement, we want to form piconets and determine routing jointly, to maximize the overall throughput. We formulate the problem of joint optimization to mixed-integer programming and give a practical lower bound that is very close to the theoretical upper bound in our simulation. Furthermore, our lower bound is much better than an algorithm that only considers topology formation in UWB networks.

  19. A novel auto-reference ultra-wideband receiver scheme

    Institute of Scientific and Technical Information of China (English)

    LIAO Xuewen; ZHU Shihua; ZENG Erlin

    2007-01-01

    A new auto-reference (AR) transmit-receive scheme and a corresponding group decision algorithm on the generaiized likelihood ratio testing(GLRT)principle is proposed in this paper to overcome the drawbacks of the power inefficiency and the high noise vulnerability in transmitted-reference(TR)ultra-wideband(UWB)systems.A partly overlapped detection window structure is introduced in which the decided data frames are regarded as the reference signal so that energy and time resources in the reference frame are saved and full-rate data transmission is achieved.Differential coding was utilized to solve the error propagation problem introduced by the overlapped detection windows.The group decision algorithm on the GLRT principle was utilized to estimate the correlation template through all data frames in detection windows and could offer better noise suppression.Simulation results reveal that the AR scheme with its decision algorithm outperforms the conventional and other modified TR schemes in generalized signal-to-noise ratio(SNR).

  20. A survey of antennas for ultra-wideband applications

    Science.gov (United States)

    Sarfaraz, Maysam; Shirkhodaie, Amir

    2008-04-01

    The usage of ultra-wideband (UWB) technology is growing in many communication systems such as radar systems, communication and measurement systems and imaging systems mainly because unlike the other wireless technologies UWB is not restricted to using a narrow waveband and it has high speed data rate. The large transmission bandwidth makes UWB-based electronic device resistive to interferences and gives immunity against getting detected. Typical operational frequency range of the UWB devices varies from few 100s MHz to 10 GHz. However, the most popular UWB devices are designed to operate between 1-3 GHz. This paper presents an overview of different types of commercially available antennas suitable for UWB applications. The paper begins with the basics of understanding of antennas properties. Next, it discusses the main antenna characteristics like: radiation pattern (directional or omni-directional), gain, bandwidth, size, etc for different UWB applications and explains criterions for quantitative and qualitative performance measure of the antennas. The antennas covered in this paper include: TEM Horn, Folded horn, Dipole, Planner Fat Dipole, Cross Dipole, Rolled Dipole, UWB dielectric, Bowtie, Wire Bowtie, etc. This paper describes the pros and cons of each antenna and highlights the application areas of each antenna. Lastly, this paper summaries the important characteristics of the antennas and presents several promising directions for future enhancement of UWB antenna systems.

  1. Interference Mitigation for Coexistence of Heterogeneous Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2006-01-01

    Full Text Available Two ultra-wideband (UWB specifications, that is, direct-sequence (DS UWB and multiband-orthogonal frequency division multiplexing (MB-OFDM UWB, have been proposed as the candidates of the IEEE 802.15.3a, competing for the standard of high-speed wireless personal area networks (WPAN. Due to the withdrawal of the standardization process, the two heterogeneous UWB technologies will coexist in the future commercial market. In this paper, we investigate the mutual interference of such coexistence scenarios by physical layer Monte Carlo simulations. The results reveal that the coexistence severely degrades the performance of both UWB systems. Moreover, such interference is asymmetric due to the heterogeneity of the two systems. Therefore, we propose the goodput-oriented utility-based transmit power control (GUTPC algorithm for interference mitigation. The feasible condition and the convergence property of GUTPC are investigated, and the choice of the coefficients is discussed for fairness and efficiency. Numerical results demonstrate that GUTPC improves the goodput of the coexisting systems effectively and fairly with saved power.

  2. Ultra-Wideband Printed Slot Radiators with Controllable Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    S. L. Chernyshev

    2015-01-01

    Full Text Available We have studied the possibility of creating ultra-wideband (UWB antennas with controlled frequency response of matching based on the printed slot antenna Vivaldi by introducing controlled resonators directly into the structure of the radiator. In the area of irregular slotline there are printed switched resonators with variable capacitance (varactor model, which allow tuning the frequency characteristics for each state of switching cavities, providing bandpass and band-barrage properties of the antenna. The investigation of reconfigurable printed resonators in the system of reconfigurable resonators of a bandpass filter is conducted. The paper considers filter to provide restructuring in the band (3-9 GHz. Electrodynamic simulation of the device was carried out in the time domain using a finite integration method. A bandstop reconfigurable filter is also investigated. The filter located on the substrate opposite the slit is based on tunable L-shaped resonator that has one end connected to the short-circuitor through the board metallization; the other end remains open and is brought into the region of interaction with the slotline. Such filter provides an effective narrow-band suppression and can be easily tuned to the desired frequency channel. The combination of these two types of filters allows you to create a controlled print Vivaldi slot antenna with combined properties. The paper investigates parameters of the scattering and radiation pattern of the antenna in different modes.

  3. Ultra-wideband spectral analysis using S2 technology

    Energy Technology Data Exchange (ETDEWEB)

    Krishna Mohan, R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States)]. E-mail: krishna@spectrum.montana.edu; Chang, T. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Tian, M. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Bekker, S. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Olson, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Ostrander, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Khallaayoun, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Dollinger, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cole, Z. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Reibel, R.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Merkel, K.D. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Sun, Y. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cone, R. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Schlottau, F. [University of Colorado, Boulder, CO 80309 (United States); Wagner, K.H. [University of Colorado, Boulder, CO 80309 (United States)

    2007-11-15

    This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution ({approx}25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 {mu}s) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed.

  4. SEMICONDUCTOR INTEGRATED CIRCUITS: A 6-9 GHz ultra-wideband CMOS PA for China's ultra-wideband standard

    Science.gov (United States)

    Zhendong, Gao; Zhiqiang, Li; Haiying, Zhang

    2010-09-01

    A 6-9 GHz ultra-wideband CMOS power amplifier (PA) for the high frequency band of China's UWB standard is proposed. Compared with the conventional band-pass filter wideband input matching methodology, the number of inductors is saved by the resistive feedback complementary amplifying topology presented. The output impendence matching network utilized is very simple but efficient at the cost of only one inductor. The measured S22 far exceeds that of similar work. The PA is designed and fabricated with TSMC 0.18 μm 1P6M RF CMOS technology. The implemented PA achieves a power gain of 10 dB with a ripple of 0.6 dB, and S11 < -10 dB over 6-9 GHz, S22 < -35 dB over 4-10 GHz. The measured output power at the 1 dB compression point is over 3.5 dBm from 6 to 9 GHz. The PA dissipates a total power of 21 mW from a 1.8 V power supply. The chip size is 1.1 × 0.8 mm2.

  5. Ultra-Wideband Optical Modulation Spectrometer (OMS) Development

    Science.gov (United States)

    Gardner, Jonathan (Technical Monitor); Tolls, Volker

    2004-01-01

    The optical modulation spectrometer (OMS) is a novel, highly efficient, low mass backend for heterodyne receiver systems. Current and future heterodyne receiver systems operating at frequencies up to a few THz require broadband spectrometer backends to achieve spectral resolutions of R approximately 10(exp 5) to 10(exp 6) to carry out many important astronomical investigations. Among these are observations of broad emission and absorption lines from extra-galactic objects at high redshifts, spectral line surveys, and observations of planetary atmospheres. Many of these lines are pressure or velocity broadened with either large half-widths or line wings extending over several GHz. Current backend systems can cover the needed bandwidth only by combining the output of several spectrometers, each with typically up to 1 GHz bandwidth, or by combining several frequency-shifted spectra taken with a single spectrometer. An ultra-wideband optical modulation spectrometer with 10 - 40 GHz bandwidth will enable broadband ob- servations without the limitations and disadvantages of hybrid spectrometers. Spectrometers like the OMS will be important for both ground-based observatories and future space missions like the Single Aperture Far-Infrared Telescope (SAFIR) which might carry IR/submm array heterodyne receiver systems requiring a spectrometer for each array pixel. Small size, low mass and small power consumption are extremely important for space missions. This report summarizes the specifications developed for the OMS and lists already identified commercial parts. The report starts with a review of the principle of operation, then describes the most important components and their specifications which were derived from theory, and finishes with a conclusion and outlook.

  6. 8th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Tyo, J. Scott; Baum, Carl E; Ultra-Wideband Short-Pulse Electromagnetics 8; UWBSP8

    2007-01-01

    The purpose of the Ultra-Wideband Short-Pulse Electromagnetics Conference series is to focus on advanced technologies for the generation, radiation and detection of ultra-wideband short pulse signals, taking into account their propagation and scattering from and coupling to targets of interest. This Conference series reports on developments in supporting mathematical and numerical methods and presents current and potential future applications of the technology. Ultra-Wideband Short-Pulse Electromagnetics 8 is based on the American Electromagnetics 2006 conference held from June 3-7 in Albuquerque, New Mexico. Topical areas covered in this volume include pulse radiation and measurement, scattering theory, target detection and identification, antennas, signal processing, and communications.

  7. Ultra-Wideband Fermi Antenna Using Microstrip-to-CPS Balun

    Science.gov (United States)

    Woo, Dong-Sik; Kim, Young-Gon; Cho, Young-Ki; Kim, Kang Wook

    A new design and experimental results of a microstrip-fed ultra-wideband Fermi antenna at millimeter-wave frequencies are presented. By utilizing a new microstrip-to-CPS balun (or transition), which provides wider bandwidth than conventional planar balun, the design of microstrip-fed Fermi antenna is greatly simplified. The proposed Fermi antenna demonstrates ultra-wideband performance for the frequency range of 23 to over 58GHz with the antenna gain of 12 to 14dBi and low sidelobe levels. This design yields highly effective solutions to various millimeter-wave phased-arrays and imaging systems.

  8. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    NARCIS (Netherlands)

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft so

  9. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    OpenAIRE

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft solves the bottleneck problems.

  10. First Experimental Impulse-Radio Ultra-Wideband Transmission Under the Russian Spectral Emission Mask

    DEFF Research Database (Denmark)

    Grakhova, Elizaveta P.; Rommel, Simon; Jurado-Navas, Antonio

    2016-01-01

    Ultra-wideband impulse-radio wireless transmission under the stringent conditions and complex shape of the Russian spectral emission mask is experimentally demonstrated for the first time. Transmission of 1Gbit/s and 1.25Gbit/s signals over distances of 6m and 3m is achieved with a BER below 3.8×...

  11. Enhanced bit rate-distance product impulse radio ultra-wideband over fiber link

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Jensen, Jesper Bevensee; Caballero Jambrina, Antonio

    2010-01-01

    We report on a record distance and bit rate-wireless impulse radio (IR) ultra-wideband (UWB) link with combined transmission over a 20 km long fiber link. We are able to improve the compliance with the regulated frequency emission mask and achieve bit rate-distance products as high as 16 Gbit/s·m....

  12. Up to 35 Gbps Ultra-Wideband Wireless Data Transmission Links

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2016-01-01

    For the first time Ultra-Wideband record data transmission rates up to 35.1 Gbps and 21.6 Gbps are achieved, compliant with the restrictions on the effective radiated power established by both the United States Federal Communications Commission and the European Electronic Communications Committee...

  13. A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Pawlik, Michal;

    2009-01-01

    A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconductor laser is proposed and experimentally demonstrated. We numerically simulate the modulation response of a direct modulation laser (DML) and show that due to the relaxation oscillations of the laser...

  14. Conformal antenna array for ultra-wideband direction-of-arrival estimation

    NARCIS (Netherlands)

    Liberal, I.; Caratelli, D.; Yarovoy, A.

    2011-01-01

    The design and full-wave analysis of an antenna system for ultra-wideband radio direction finding applications is presented. The elliptical dipole antenna is selected as antenna element due to its robust circuital and radiation properties. The influence of the conformal deformation on the antenna

  15. Conformal antenna array for ultra-wideband direction-of-arrival estimation

    NARCIS (Netherlands)

    Liberal, I.; Caratelli, D.; Yarovoy, A.

    2011-01-01

    The design and full-wave analysis of an antenna system for ultra-wideband radio direction finding applications is presented. The elliptical dipole antenna is selected as antenna element due to its robust circuital and radiation properties. The influence of the conformal deformation on the antenna pe

  16. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1999-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  17. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1998-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  18. 35 Gb/s Ultra-wideband Technology for Advanced Communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    as ordinary noise. Furthermore, this technology allows unlicensed operation, provided standards and regulations are fulfilled. On the other hand, in current fast evolving scenarios, secure communications at the physical layer will soon become a requirement by the end users. Existing security techniques...... be applied, evolving from classic spectral inefficient pulsebased systems to more advanced and flexible modulation schemes. Ultra-wideband technology is suitable for low-power high-speed wireless communication systems over short distances, and is an appealing alternative for next generation networks ranging...... from high-speed wireless personal area networks, to the internet of things applications. Its popularity stems from the fact that they can be used as an overlay to existing systems, without interference, operating in parallel to existing wireless systems, which perceive ultra-wideband emissions...

  19. Analysis and Design of Tapered Slot Antenna for Ultra-Wideband Applications

    Institute of Scientific and Technical Information of China (English)

    YAO Yuan; CHEN Wenhua; HUANG Bin; FENG Zhenghe; ZHANG Zhijun

    2009-01-01

    The tapered slot antenna,such as Vivaldi,has been widely used due to its ultra-wideband,high gain,simple feed structure,and easy fabrication.However,there is no rigorous analytical theory for this type of antenna.This paper analyzed the metal parts of a tapered slot antenna in a conical coordinate system with the medium analyzed in rectangular coordinates.This mixed mode gave an approximate analytical form for the tapered slot antenna with the field distribution and radiation characteristics.A planar tapered slot antenna was proposed according to the results of the analysis methods.Measured and simulated results demonstrate the antenna performance.The antenna shows good impedance matching over a wide bandwidth of 9 GHz,from 2 GHz to 11 GHz,and good radiation patterns.It is suitable for ultra-wideband applications.

  20. Design and study of a compact planar ultra-wideband antenna

    Institute of Scientific and Technical Information of China (English)

    CHENG Yong; LU Wenjun; CHENG Chonghu; CAO Wei

    2007-01-01

    In this paper,a novel,small,and compact planar antenna for ultra-wideband(UWB)applications is proposed.The antenna is an extension of microstrip slot antenna technology.To achieve ultra-wideband characteristics,a tapered microstrip fork-shaped stub has been employed.A symmetric polygon wide slot has been placed on the antenna ground.The design was investigated numerically to obtain proper dimensions for the antenna and a prototype was constructed.The return loss,pattern and gain of the prototype antenna have been measured.The transient pulse signal fidelity has also been investigated by finite-difference time-domain (FDTD)method.Experimental results show that the proposed antenna design has promising characteristics for UWB applications.

  1. 10th and 11th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Mokole, Eric; UWB SP 10; UWB SP 11

    2014-01-01

    This book presents contributions of deep technical content and high scientific quality in the areas of electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-resolution techniques. Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Like previous books in this series, Ultra-Wideband Short-Pulse Electrom...

  2. 7th conference on ultra-wideband, short-pulse electromagnetics

    CERN Document Server

    Schenk, Uwe; Nitsch, Daniel; Sabath, Frank; Ultra-Wideband, Short-Pulse Electromagnetics 7; UWBSP7

    2007-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-Wideband Short-Pulse Electromagnetics 7 presents selected papers of deep technical content and high scientific quality from the UWB-SP7 Conference, including wide-ranging contributions on electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-res...

  3. High-speed ultra-wideband wireless signals over fiber systems: photonic generation and DSP detection

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We firstly review the efforts in the literature on ultra-wideband (UWB)-over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduc...... the use of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

  4. Tomographic imaging with ultra-wideband noise radar using time-domain data

    Science.gov (United States)

    Shin, Hee Jung; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2013-05-01

    This paper investigates the feasibility of using a noise waveform in an ultra-wideband (UWB) radar system for two-dimensional tomographic imaging of a stationary object with a multistatic tomographic geometry. Multiple UWB transmitters and receivers are positioned along each side of the imaging area. We perform several numerical simulations in time-domain, and the successful imaging of the target is achieved by visual inspection of the formed images.

  5. Ultra-wideband short-pulse radar with range accuracy for short range detection

    Science.gov (United States)

    Rodenbeck, Christopher T; Pankonin, Jeffrey; Heintzleman, Richard E; Kinzie, Nicola Jean; Popovic, Zorana P

    2014-10-07

    An ultra-wideband (UWB) radar transmitter apparatus comprises a pulse generator configured to produce from a sinusoidal input signal a pulsed output signal having a series of baseband pulses with a first pulse repetition frequency (PRF). The pulse generator includes a plurality of components that each have a nonlinear electrical reactance. A signal converter is coupled to the pulse generator and configured to convert the pulsed output signal into a pulsed radar transmit signal having a series of radar transmit pulses with a second PRF that is less than the first PRF.

  6. Design and Validation of an Optimized MB-OFDM Ultra Wideband Transceiver System

    OpenAIRE

    Liang, Guixuan

    2013-01-01

    Esta tesis está incluida dentro del campo del campo de Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband (MB-OFDM UWB), el cual ha adquirido una gran importancia en las comunicaciones inalámbricas de alta tasa de datos en la última década. UWB surgió con el objetivo de satisfacer la creciente demanda de conexiones inalámbricas en interiores y de uso doméstico, con bajo coste y alta velocidad. La disponibilidad de un ancho de banda grande, el potencial para alta velocidad de ...

  7. Paper-based inkjet-printed ultra-wideband fractal antennas

    KAUST Repository

    Maza, Armando Rodriguez

    2012-01-01

    For the first time, paper-based inkjet-printed ultra-wideband (UWB) fractal antennas are presented. Two new designs, a miniaturised UWB monopole, which utilises a fractal matching network and is the smallest reported inkjet-printed UWB printed antenna to date, and a fourth-order Koch Snowflake monopole, which utilises a Sierpinski gasket fractal for ink reduction, are demonstrated. It is shown that fractals prove to be a successful method of reducing fabrication costs in inkjet-printed antennas, while retaining or enhancing printed antenna performance. © 2012 The Institution of Engineering and Technology.

  8. Optical Transmission of OFDM Ultra-wideband Signals beyond 40 Gb/s (Invited Paper

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ezra

    2010-02-01

    Full Text Available We for the first time propose the highly efficient method of RF and optical signal mixing based on two different architectures: the parallel-RF/serial-optics architecture characterized by all-optical mixing for sub-carrier multiplexing, and the parallel-RF/parallel-optics architecture based on the array of 12x10 GHz components with directly modulated VCSELs and 12 multimode optical fibers. The main advantages of the both architectures are simplicity and low-cost implementation. We have carried out numerical simulations of ultra-wideband signals propagation in the proposed systems and proved the high efficiency and feasibility of the proposed method.

  9. Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

    Science.gov (United States)

    Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

    2017-01-01

    Next generation 5G mobile architectures will take advantage of the millimeter-wave spectrum to deliver unprecedented bandwidth. Concurrently, there is a need to consolidate numerous disparate allocations into a single, multi-functional array. Existing arrays are either narrow-band, prohibitively expensive or cannot be scaled to these frequencies. In this paper, we present the first ultra-wideband millimeter-wave array to operate across the six 5G and ISM bands spanning 24-71 GHz. Critically, the array is realized using low-cost PCB. The design concept and optimized layout are presented, and fabrication and measurement considerations are discussed.

  10. Fiber extended ultra-wideband radar for breath tracking through 10 cm concrete

    DEFF Research Database (Denmark)

    Suhr, Lau Frejstrup; Tafur Monroy, Idelfonso; Vegas Olmos, Juan José

    2016-01-01

    This article presents an Ultra-Wideband (UWB) radar with a 20 km NZ-DSF extension on the transmitter side. The radar is based on telecom class signal generation, antennas, and a recording module operating at 20 Gsa/s. The radar is transmitting a pulse covering the frequencies from 3.4 to 9.9 GHz........ The radar system was able to track the breathing of a human through a 10 cm concrete obstacle. The frequency output was verified through the use of a metal pendulum with a fixed oscillation period...

  11. Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide

    DEFF Research Database (Denmark)

    Xiao, Binggang; Li, Sheng-Hua; Xiao, Sanshui

    2016-01-01

    Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN...... and satellite communication interference simultaneously. Both the cutoff frequency and the notch frequency are sensitive to the structure parameters, and the cut-off frequency can reach 20 GHz. An adiabatic transition relying on gradient hole-size and flaring ground is designed to effectively couple energy...

  12. Novel ultra-wideband photonic signal generation and transmission featuring digital signal processing bit error rate measurements

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

    2009-01-01

    We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal.......We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal....

  13. Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, F; Dowla, F

    2009-10-19

    Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

  14. Flexible ultra-wideband antenna incorporated with metamaterial structures: multiple notches for chipless RFID application

    Science.gov (United States)

    Jalil, M. E.; Rahim, M. K. A.; Samsuri, N. A.; Dewan, R.; Kamardin, K.

    2017-01-01

    A coplanar waveguide (CPW) ultra-wideband (UWB) antenna incorporated with metamaterial—split ring resonator structure—that operates from 3.0 to 12.0 GHz is proposed for chipless RFID tag. The 30 mm × 40 mm flexible chipless RFID tag is designed on the fleece substrate ( ɛ r = 1.35, thickness = 1 mm and tan δ = 0.025). A six-slotted modified complementary split ring resonator (MCSRR) is introduced into the ultra-wideband antenna to produce multiple band notches at 3.0, 4.0, 5.0, 6.0 and 7.0 GHz. The frequency shifting technique is introduced for designing a high-capacity chipless RFID tag with compact size. Each MCSRR is able to code in four different allocations (00, 01, 10 and 11). To achieve encoding of 10-bits data (10,234 number), six MCSRRs are proposed with three-slotted MCSRR in the radiator and three-slotted MCSRR in the ground plane.

  15. Ultra-wideband filtering of spoof surface plasmon polaritons using deep subwavelength planar structures

    Science.gov (United States)

    Hu, Ming Zhe; Zhang, Hao Chi; Yin, Jia Yuan; Ding, Zhao; Liu, Jun Feng; Tang, Wen Xuan; Cui, Tie Jun

    2016-11-01

    Novel ultra-wideband filtering of spoof surface plasmon polaritons (SPPs) is proposed in the microwave frequency using deep subwavelength planar structures printed on thin and flexible dielectric substrate. The proposed planar SPPs waveguide is composed of two mirror-oriented metallic corrugated strips, which are further decorated with parallel-arranged slots in the main corrugated strips. This compound structure provides deep subwavelength field confinement as well as flexible parameters when employed as a plasmonic waveguide, which is potential to construct miniaturization. Using momentum and impedance matching technology, we achieve a smooth conversion between the proposed SPPs waveguide and the conventional transmission line. To verify the validity of the design, we fabricate a spoof SPPs filter, and the measured results illustrate excellent performance, in which the reflection coefficient is less than ‑10 dB within the ‑3 dB passband from 1.21 GHz to 7.21 GHz with the smallest insertion loss of 1.23 dB at 2.21 GHz, having very good agreements with numerical simulations. The ultra-wideband filter with low insertion loss and high transmission efficiency possesses great potential in modern communication systems.

  16. Ultra-wideband filtering of spoof surface plasmon polaritons using deep subwavelength planar structures

    Science.gov (United States)

    Hu, Ming Zhe; Zhang, Hao Chi; Yin, Jia Yuan; Ding, Zhao; Liu, Jun Feng; Tang, Wen Xuan; Cui, Tie Jun

    2016-01-01

    Novel ultra-wideband filtering of spoof surface plasmon polaritons (SPPs) is proposed in the microwave frequency using deep subwavelength planar structures printed on thin and flexible dielectric substrate. The proposed planar SPPs waveguide is composed of two mirror-oriented metallic corrugated strips, which are further decorated with parallel-arranged slots in the main corrugated strips. This compound structure provides deep subwavelength field confinement as well as flexible parameters when employed as a plasmonic waveguide, which is potential to construct miniaturization. Using momentum and impedance matching technology, we achieve a smooth conversion between the proposed SPPs waveguide and the conventional transmission line. To verify the validity of the design, we fabricate a spoof SPPs filter, and the measured results illustrate excellent performance, in which the reflection coefficient is less than −10 dB within the −3 dB passband from 1.21 GHz to 7.21 GHz with the smallest insertion loss of 1.23 dB at 2.21 GHz, having very good agreements with numerical simulations. The ultra-wideband filter with low insertion loss and high transmission efficiency possesses great potential in modern communication systems. PMID:27883028

  17. Pulse shaping for high data rate ultra-wideband wireless transmission under the Russian spectral emission mask

    DEFF Research Database (Denmark)

    Rommel, Simon; Grakhova, Elizaveta P.; Jurado-Navas, Antonio

    2017-01-01

    This paper addresses impulse-radio ultra-wideband (IR-UWB) transmission under the Russian spectral emission mask for unlicensed UWB radio communications. Four pulse shapes are proposed and their bit error rate (BER) performance is both estimated analytically and evaluated experimentally. Well-kno...

  18. An ultra-wideband dielectric material characterization method using grounded coplanar waveguide and genetic algorithm optimization

    Science.gov (United States)

    Hadjloum, Massinissa; El Gibari, Mohammed; Li, Hongwu; Daryoush, Afshin S.

    2015-10-01

    An ultra-wideband complex permittivity extraction method is reported here using numerical fitting of scattering parameters to measured results. A grounded coplanar waveguide transmission line is realized on an unknown dielectric material, whose dielectric constant and loss tangent are extracted by the best fitting of the simulated magnitude, |S21|, and phase, ϕ21, of forward scattering parameter using an electromagnetic full-wave simulator (high frequency structure simulator) to the measured results. The genetic algorithm is employed for optimum rapid extraction, where errors between the numerically simulated and measured S21 (|S21| and ϕ21) are minimized in an iterative manner. As long as the convergence criterion is not satisfied, modifications to dielectric properties are made with this genetic algorithm implemented in Matlab. Feasibility of this extraction technique is validated on benzocyclobutane polymer from 10 MHz to 40 GHz.

  19. Low-sampling-rate ultra-wideband digital receiver using equivalent-time sampling

    KAUST Repository

    Ballal, Tarig

    2014-09-01

    In this paper, we propose an all-digital scheme for ultra-wideband symbol detection. In the proposed scheme, the received symbols are sampled many times below the Nyquist rate. It is shown that when the number of symbol repetitions, P, is co-prime with the symbol duration given in Nyquist samples, the receiver can sample the received data P times below the Nyquist rate, without loss of fidelity. The proposed scheme is applied to perform channel estimation and binary pulse position modulation (BPPM) detection. Results are presented for two receivers operating at two different sampling rates that are 10 and 20 times below the Nyquist rate. The feasibility of the proposed scheme is demonstrated in different scenarios, with reasonable bit error rates obtained in most of the cases.

  20. Emerging Communication Technologies (ECT) Phase 2 Report. Volume 3; Ultra Wideband (UWB) Technology

    Science.gov (United States)

    Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

    2003-01-01

    The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB

  1. Ultra-Wideband Geo-Regioning: A Novel Clustering and Localization Technique

    Directory of Open Access Journals (Sweden)

    Armin Wittneben

    2007-12-01

    Full Text Available Ultra-wideband (UWB technology enables a high temporal resolution of the propagation channel. Consequently, a channel impulse response between transmitter and receiver can be interpreted as signature for their relative positions. If the position of the receiver is known, the channel impulse response indicates the position of the transmitter and vice versa. This work introduces UWB geo-regioning as a clustering and localization method based on channel impulse response fingerprinting, develops a theoretical framework for performance analysis, and evaluates this approach by means of performance results based on measured channel impulse responses. Complexity issues are discussed and performance dependencies on signal-to-noise ratio, a priori knowledge, observation window, and system bandwidth are investigated.

  2. UTag: Long-range Ultra-wideband Passive Radio Frequency Tags

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F

    2007-03-14

    Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.

  3. Design of an Ultra-Wideband Transition from Double-Sided Parallel Stripline to Coplanar Waveguide

    Directory of Open Access Journals (Sweden)

    Young-Gon Kim

    2013-01-01

    Full Text Available A design method of an ultra-wideband transition from double-sided parallel stripline (DSPSL to coplanar waveguide (CPW is proposed based on analytical expressions of characteristic impedance. The conformal mapping is used to obtain the characteristic impedance for each section of the transition within 3.7% accuracy as compared with the EM simulation results. An efficient and clear guideline for the design of the transition is proposed. The implemented transition performs less than 0.6 dB insertion loss per transition for frequencies from 40 MHz to 12 GHz and less than 1.2 dB insertion loss to 27 GHz, which well exceeds the previous results in the literature.

  4. Study of ultra-wideband radar signals-generated technology using two-channel signal generator

    Institute of Scientific and Technical Information of China (English)

    Wan Yonglun; Lu Youxin; Si Qiang; Wang Xuegang; Cao Guangping

    2007-01-01

    Synthesis of ultra-wideband (UWB) linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section (RCS) targets. A new method of UWB radar signals generation with two-channel signal generator is presented. The realization structure is given; the principle and errors of signal synthesis are analyzed. At the same time, an automatic adjustment measure of signal phase is proposed because of phase discontinuity of waveform in this method. The simulation experiment and analysis results indicate that radar signals with large instantaneous bandwidth can be generated by means of this method on the condition that the high-speed digital devices are limited.

  5. Millimeter-Wave Ultra-Wideband Six-Port Receiver Using Cross-Polarized Antennas

    Directory of Open Access Journals (Sweden)

    Wu Ke

    2009-01-01

    Full Text Available This paper presents a new low-cost millimeter-wave ultra-wideband (UWB transceiver architecture operating over V-band from 60 to 64 GHz. Since the local oscillator (LO power required in the operation of six-port receiver is generally low (compared to conventional one using diode mixers, the carrier recovery or LO synchronization is avoided by using second transmission path and cross-polarized antennas. The six-port model used in system simulation is based on -parameters measurements of a rectangular waveguide hybrid coupler. The receiver architecture is validated by comparisons between transmitter and receiver bit sequences and bit error rate results of 500 Mb/s pseudorandom QPSK signal.

  6. Millimeter-Wave Ultra-Wideband Six-Port Receiver Using Cross-Polarized Antennas

    Directory of Open Access Journals (Sweden)

    Serioja O. Tatu

    2009-01-01

    Full Text Available This paper presents a new low-cost millimeter-wave ultra-wideband (UWB transceiver architecture operating over V-band from 60 to 64 GHz. Since the local oscillator (LO power required in the operation of six-port receiver is generally low (compared to conventional one using diode mixers, the carrier recovery or LO synchronization is avoided by using second transmission path and cross-polarized antennas. The six-port model used in system simulation is based on S-parameters measurements of a rectangular waveguide hybrid coupler. The receiver architecture is validated by comparisons between transmitter and receiver bit sequences and bit error rate results of 500 Mb/s pseudorandom QPSK signal.

  7. A low-power high-speed ultra-wideband pulse radio transmission system.

    Science.gov (United States)

    Wei Tang; Culurciello, E

    2009-10-01

    We present a low-power high-speed ultra-wideband (UWB) transmitter with a wireless transmission test platform. The system is specifically designed for low-power high-speed wireless implantable biosensors. The integrated transmitter consists of a compact pulse generator and a modulator. The circuit is fabricated in the 0.5-mum silicon-on-sapphire process and occupies 420 mum times 420 mum silicon area. The transmitter is capable of generating pulses with 1-ns width and the pulse rate can be controlled between 90 MHz and 270 MHz. We built a demonstration/testing system for the transmitter. The transmitter achieves a 14-Mb/s data rate. With 50% duty cycle data, the power consumption of the chip is between 10 mW and 21 mW when the transmission distance is from 3.2 to 4 m. The core circuit size is 70 mum times 130 mum.

  8. A compact ultra wideband antenna with WiMax band rejection for energy scavenging

    Science.gov (United States)

    Jalil, Y. E.; Kasi, B.; Chakrabarty, C. K.

    2013-06-01

    Radio Frequency (RF) energy harvesting has been rapidly advancing as a promising alternative to existing energy scavenging system. A well designed broadband antenna such as ultra-wideband (UWB) antenna can be used as one of the major components in an RF energy scavenging system. This paper presents a compact UWB antenna showing good impedance matching over a bandwidth of 2.8 to 11 GHz, suiTable for broadband RF energy scavenging. Nevertheless, the antenna usage in wireless communication has a limitation due to the problem of interference between UWB system and other narrowband systems. Thus, the proposed antenna is successfully designed with a single band-notched at the targeted WiMAX operating band of 3.3 to 3.6 GHz.

  9. Ultra-Wideband Channel Sounder – Design, Construction and Selected Applications

    Directory of Open Access Journals (Sweden)

    R. Zetik

    2013-06-01

    Full Text Available The paper describes construction, design, and application of a real-time ultra-wideband channel sounder. Its specific architecture allows measurements of time-variant radio propagation channels in different frequency bands. The sounder’s stimulation signal is the maximum length binary sequence. Synchronous multi-channel operation is supported by its excellent timing stability and by its low power consumption of miniature sized low temperature co-fired ceramics modules that comprise custom integrated SiGe circuits. This is a prerequisite to build a multiple-input-multiple-output sounder which is suitable for sounding even in distributed scenarios such as sensor networks. Selected application examples demonstrated the performance and possibilities of the sounder.

  10. Pulse shaping method to compensate for antenna distortion in ultra-wideband communications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the ultra-wideband (UWB) communication systems, a critical spectral mask is released to restrict the allowable interference to other wireless devices by the Federal Communications Commission (FCC), and then some pulse shaping methods have been presented to fulfil the mask. However, most pulse shaping methods do not consider the antenna distortion which cannot be neglected in the UWB communication systems compared with the conventional systems. To this end, an orthogonal wavelet based pulse shaping method is proposed in this paper to integrate compensation of antenna distortion into pulse shaping. Simulation results show that the novel pulse shaping method can be used to achieve compensation for antenna distortion, optimization of transmission power spectrum, and simplification of the algorithm, as well as simple implementation of the pulse generator.

  11. Ultra Wideband Signal Detection with a Schottky Diode Based Envelope Detector

    DEFF Research Database (Denmark)

    Rommel, Simon; Cimoli, Bruno; Valdecasa, Guillermo Silva

    its interoperability with existing wireless services and its license free operation. The latter is conditioned on meeting a number of standards and regulations for maximum radiated powers, designed to ensure the former by defining uwb signals as signals with large bandwidths in the frequency range...... of 2.85 GHz to 10.6 GHz and low power spectral density radio frequency (rf) emission. The use of such low power levels ensures non-problematic coexistence with other already deployed wireless technologies – e.g. WiFi, GPS and mobile services – and allows deployment in environments sensitive to rf....... The receiver is able to detect an ultra-wideband signal compliant with the Federal Communications Commission (fcc) regulations for uwb transmission and consisting of a 2.5 Gbit/s non-return-to-zero (nrz) data signal on a 6.9 GHz carrier after 20 cm wireless transmission. Bit error rates (ber) below the forward...

  12. Medium Access Control for Wireless Sensor Networks based on Impulse Radio Ultra Wideband

    CERN Document Server

    Berthe, Abdoulaye; Dragomirescu, Daniela; Plana, Robert

    2010-01-01

    This paper describes a detailed performance evaluation of distributed Medium Access Control (MAC) protocols for Wireless Sensor Networks based on Impulse Radio Ultra Wideband (IR-UWB) Physical layer (PHY). Two main classes of Medium Access Control protocol have been considered: Slotted and UnSlotted with reliability. The reliability is based on Automatic Repeat ReQuest (ARQ). The performance evaluation is performed using a complete Wireless Sensor Networks (WSN) simulator built on the Global Mobile Information System Simulator (GloMoSim). The optimal operating parameters are first discussed for IR-UWB in terms of slot size, retransmission delay and the number of retransmission, then a comparison between IR-UWB and other transmission techniques in terms of reliability latency and power efficiency.

  13. Abstracts of papers presented at the First Los Alamos Symposium on Ultra-Wideband Radar

    Science.gov (United States)

    Noel, B. W.

    1991-07-01

    To provide an open and unbiased forum for exchanging ideas and research results among specialists in the field of radar and related topics, the First Los Alamos Symposium on Ultra-Wideband Radar was held at Los Alamos National Laboratory March 3 to 7, 1990. This document contains copies of the abstracts of the papers presented at the symposium. More than 200 scientists and engineers from the United States, Canada, and Great Britain attended the symposium. They heard 75 papers that I tried to categorize into seven subject areas: fundamental topics, computational electromagnetics, applications, new technologies, signal propagation, signal processing, and testing. Of the 75 papers, roughly 45 of the full texts are scheduled to be published in book form by CRC Press.

  14. Impulse Radio Ultra-Wideband Communication Over Free-Space Optical Links

    CERN Document Server

    Davaslioglu, Kemal

    2013-01-01

    A composite impulse radio ultra-wideband (IR-UWB) communication system is presented. The proposed system model aims to transmit UWB pulses over several kilometers through free-space optical (FSO) links and depending on the link design, the electrical estimates of the FSO system can be directly used or distributed to end-user through radio-frequency (RF) links over short ranges. However, inhomogeneities on the FSO transmission path cause random fluctuations in the received signal intensity and these effects induced by atmospheric turbulence closely effect the system performance. Several distinct probability distributions based on experimental measurements are used to characterize FSO channels and using these probabilistic models, detection error probability analysis of the proposed system for different link designs are carried out under weak, moderate and strong turbulence conditions. The results of the analysis show that depending on the atmospheric conditions, system performance of the composite link can hav...

  15. Statistical-physical model for foliage clutter in ultra-wideband synthetic aperture radar images.

    Science.gov (United States)

    Banerjee, Amit; Chellappa, Rama

    2003-01-01

    Analyzing foliage-penetrating (FOPEN) ultra-wideband synthetic aperture radar (SAR) images is a challenging problem owing to the noisy and impulsive nature of foliage clutter. Indeed, many target-detection algorithms for FOPEN SAR data are characterized by high false-alarm rates. In this work, a statistical-physical model for foliage clutter is proposed that explains the presence of outliers in the data and suggests the use of symmetric alpha-stable (SalphaS) distributions for accurate clutter modeling. Furthermore, with the use of general assumptions of the noise sources and propagation conditions, the proposed model relates the parameters of the SalphaS model to physical parameters such as the attenuation coefficient and foliage density.

  16. Time-domain ultra-wideband radar, sensor and components theory, analysis and design

    CERN Document Server

    Nguyen, Cam

    2014-01-01

    This book presents the theory, analysis, and design of ultra-wideband (UWB) radar and sensor systems (in short, UWB systems) and their components. UWB systems find numerous applications in the military, security, civilian, commercial and medicine fields. This book addresses five main topics of UWB systems: System Analysis, Transmitter Design, Receiver Design, Antenna Design and System Integration and Test. The developments of a practical UWB system and its components using microwave integrated circuits, as well as various measurements, are included in detail to demonstrate the theory, analysis and design technique. Essentially, this book will enable the reader to design their own UWB systems and components. In the System Analysis chapter, the UWB principle of operation as well as the power budget analysis and range resolution analysis are presented. In the UWB Transmitter Design chapter, the design, fabrication and measurement of impulse and monocycle pulse generators are covered. The UWB Receiver Design cha...

  17. Experimental Characterization of Ultra-Wideband Channel Parameter Measurements in an Underground Mine

    Directory of Open Access Journals (Sweden)

    B. Nkakanou

    2011-01-01

    Full Text Available Experimental results for an ultra-wideband (UWB channel parameters in an underground mining environment over a frequency range of 3 GHz to 10 GHz are reported. The measurements were taken both in LOS and NLOS cases in two different size mine galleries. In the NLOS case, results were acquired for different corridor obstruction angles. The results were obtained during an extensive measurement campaign in the UWB frequency, and the measurement procedure allows both the large- and small-scale parameters such as the path loss exponent, coherence bandwidth, and so forth, to be quantified. The capacity of the UWB channel as a function of the physical depth of the mine gallery has also been recorded for comparison purposes.

  18. Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

    Science.gov (United States)

    Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

    2017-01-01

    Growing mobile data consumption has prompted the exploration of the millimeter-wave spectrum for large bandwidth, high speed communications. However, the allocated bands are spread across a wide swath of spectrum: Fifth generation mobile architecture (5G): 28, 38, 39, 6471 GHz; Industrial, Scientific, and Medical bands (ISM): 24, 60 GHz. Moreover, high gain phased arrays are required to overcome the significant path loss associated with these frequencies. Further, it is necessary to incorporate several of these applications in a single, small size and low cost platform. To this end, we have developed a scanning, Ultra-Wideband (UWB) array which covers all 5G, ISM, and other mm-W bands from 2472 GHz. Critically, this is accomplished using mass-production Printed Circuit Board (PCB) fabrication. The results of this work are presented in this poster.

  19. Experimental implant communication of high data rate video using an ultra wideband radio link.

    Science.gov (United States)

    Chávez-Santiago, Raúl; Balasingham, Ilangko; Bergsland, Jacob; Zahid, Wasim; Takizawa, Kenichi; Miura, Ryu; Li, Huan-Bang

    2013-01-01

    Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720 pixels video at 80 Mbps through a UWB multiband orthogonal frequency division multiplexing (MB-OFDM) interface in a porcine chirurgical model. The results demonstrated successful transmission up to a maximum depth of 30 mm in the abdomen and 33 mm in the thorax within the 4.2-4.8 GHz frequency band.

  20. Ultra-wideband signal generator based on cross gain modulation effect in a distributed feedback laser

    Science.gov (United States)

    Chen, Dalei; Wang, Rong; Xiang, Peng; Pu, Tao; Fang, Tao; Li, Yuandong; Su, Yang; Zheng, Jiling; Huang, Long; Zhu, Huatao; Huang, Jie

    2016-10-01

    In this paper, a novel scheme to generate ultra-wideband (UWB) signals based on cross-gain modulation (XGM) effect in a DFB laser is proposed and experimentally demonstrated, and the modulation and transmission of the UWB signals are also experimentally investigated. In the proposed system, a gain-switched laser (GSL) is used as master laser (ML) and the optical pulses from the ML are optically injected into a DFB laser, which is used as slave laser (SL). By proper system configuration, UWB monocycle, doublet or triplet UWB signals can be generated after the balanced photodiode (BPD) detection. Besides, other modulation formats can also be realized, such as on-off keying (OOK) and pulse amplitude modulation (PAM) by properly modulating the ML optical pulses. Finally, fiber transmission of the modulated UWB signals is experimentally investigated, and it is shown that the UWB signals can be well maintained after 40 km optical fiber transmission.

  1. Power-Efficient Ultra-Wideband Waveform Design Considering Radio Channel Effects

    Directory of Open Access Journals (Sweden)

    Yipeng Liu

    2011-04-01

    Full Text Available This paper presents a power-efficient maskconstrained ultra-wideband (UWB waveform design with radio channel effects taken into consideration. Based on a finite impulse response (FIR filter, we develop a convex optimization model with respect to the autocorrelation of the filter coefficients to optimize the transmitted signal power spectrum, subject to a regulatory emission mask. To improve power efficiency, effects of transmitter radio frequency (RF components are included in the optimization of the transmitter-output waveform, and radio propagation effects are considered for obtaining the most efficient waveform at the receiver. Optimum coefficients of the FIR filter are obtained through spectral factorization of their autocorrelations. Simulation results show that the proposed method is able to maximize the transmitted UWB signal power under mask constraints set by regulatory authorities, while mitigating the power loss caused by channel attenuations.

  2. Ultra-Wideband Phased Array for Millimeter-Wave 5G and ISM

    Science.gov (United States)

    Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

    2016-01-01

    Growing mobile data consumption has prompted the exploration of the millimeter-wave spectrum for large bandwidth, high speed communications. However, the allocated bands are spread across a wide swath of spectrum: fifth generation mobile architecture (5G): 28, 38, 39, 64-71 GHz, as well as Industrial, Scientific, and Medical bands (ISM): 24 and 60 GHz. Moreover, high gain phased arrays are required to overcome the significant path loss associated with these frequencies. Further, it is necessary to incorporate several of these applications in a single, small size and low cost platform. To this end, we have developed a scanning, Ultra-Wideband (UWB) array which covers all 5G, ISM, and other mm-W bands from 24-72 GHz. Critically, this is accomplished using mass-production Printed Circuit Board (PCB) fabrication.

  3. Study on the Generation of Ultra-Wideband (UWB) High Power Microwave

    Institute of Scientific and Technical Information of China (English)

    樊亚军; 刘国治; 刘小龙; 宋晓欣; 刘锋; 石磊

    2003-01-01

    The experimental study of ultra-wideband (UWB) technology, its generation and on-line measurement are presented. An experimental repetitive UWB system is designed, manufactured, and tested. High-pressure spark gap switch and its components, as well as oil spark gap switch are studied experimentally on the system. Experimental results indicate that the system operates at a 200 pps repetitive rate with a stable performance. 100 MW peak power UWB pulses are obtained on the system. Fast-time response capacitive divider is designed and fabricated, allowing for an accurate measurement of the high power UWB signal. The main issues related to the design of the switch and the UWB signal online measurement are discussed.

  4. Ultra-wideband wireless receiver front-end for high-speed indoor applications

    Directory of Open Access Journals (Sweden)

    Zhe-Yang Huang

    2014-12-01

    Full Text Available Low-noise, ultra-wideband (UWB wireless receiver front-end circuits were presented in this study. A two-stage common-source low-noise amplifier with wideband input impedance matching network, an active-balun and a double-balanced down-conversion mixer were adopted in the UWB wireless receiver front-end. The proposed wireless receiver front-end circuits were implemented in 0.18 μm radio-frequency-CMOS process. The maximum down-conversion power gain of the front-end is 25.8 dB; minimum single-sideband noise figure of the front-end is 4.9 dB over complete UWB band ranging from 3.1 to 10.6 GHz. Power consumption including buffers is 39.2 mW.

  5. Ultra-wideband noise radar imaging of cylindrical PEC objects using diffraction tomography

    Science.gov (United States)

    Shin, Hee Jung; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2014-05-01

    In this paper, we show that a single transmission of a random noise waveform may not sufficient to obtain a successful tomographic image of an object. In order to overcome this shortcoming, multiple independent and identically distributed (iid) random noise waveforms over a frequency range from 8 to 10 GHz are transmitted to reconstruct the final image of various objects. Diffraction tomography theorem is applied for each noise waveform transmission so that the image of the multiple objects is reconstructed based on the backward scattered field at the end of each noise waveform transmission realization. After all iid noise waveforms are transmitted, the final tomographic image of the target is reconstructed by averaging all obtained images from multiple transmissions. Several numerical simulations in the spatial frequency domain are performed, and the successful tomographic image of the multiple cylindrical PEC objects is achieved after transmission of multiple iid ultra-wideband (UWB) random noise waveforms.

  6. Design and analysis of ultra-wideband antennas for transient field excitations

    Science.gov (United States)

    Kotzev, Miroslav; Kreitlow, Matthias; Gronwald, Frank

    2016-09-01

    This work addresses the design of two ultra-wideband antennas for the application of transient field measurements that are characterized by frequency spectra that typically range from a few MHz to several GHz. The motivation for their design is the excitation of high power transient pulses, such as double exponential or damped sinusoidal pulses, within highly resonant metallic enclosures. The antenna design is based on two independent numerical full-wave solvers and it is aimed to achieve a low return loss over a wide range of frequencies together with a high pulse fidelity. It turns out that antennas of the conical and discone type do achieve satisfactory broadband characteristics while limitations towards low frequencies persist. Also the concept of fidelity factor turns out as advantageous to determine whether the proposed antennas allow transmitting certain broadband pulse forms.

  7. Low-complexity Wireless Monitoring of Respiratory Movements Using Ultra-wideband Impulse Response Estimation

    KAUST Repository

    Sana, Furrukh

    2014-03-01

    In this paper; we present a comprehensive scheme for wireless monitoring of the respiratory movements in humans. Our scheme overcomes the challenges low signal-to-noise ratio, background clutter and high sampling rates. It is based on the estimation of the ultra-wideband channel impulse response. We suggest techniques for dealing with background clutter in situations when it might be time variant. We also present a novel methodology for reducing the required sampling rate of the system significantly while achieving the accuracy offered by the Nyquist rate. Performance results from simulations conducted with pre-recorded respiratory signals demonstrate the robustness of our scheme for tackling the above challenges and providing a low-complexity solution for the monitoring of respiratory movements.

  8. In-Body to On-Body Ultra WidebandPropagation Model Derived from Measurementsin Living Animals

    OpenAIRE

    Floor, Pål Anders; Chavez-Santiago, Raul; Brovoll, Sverre; Aardal, Øyvind; Bergsland, Jacob; Grymyr, Ole-Johannes; Halvorsen, Per Steinar; Palomar, Rafael; Plettemeier, Dirk; Hamran, Svein-Erik; Ramstad, Tor Audun; Balasingham, Ilangko

    2015-01-01

    Ultra wideband (UWB) radio technology for wireless implants has gained significant attention. UWB enables the fabrication of faster and smaller transceivers with ultra low power consumption, which may be integrated into more sophisticated implantable biomedical sensors and actuators. Nevertheless, the large path loss suffered by UWB signals propagating through inhomogeneous layers of biological tissues is a major hindering factor. For the optimal design of implantable transceivers, the accura...

  9. Development of an Ultra-Wideband Receiver for the North America Array

    Science.gov (United States)

    Velazco, J. E.; Soriano, M.; Hoppe, D.; Russell, D.; D'Addario, L.; Long, E.; Bowen, J.; Samoska, L.; Lazio, J.

    2016-11-01

    The North America Array (NAA) is a concept for a radio astronomical interferometric array operating in the 1.2 GHz to 116 GHz frequency range. It has been designed to provide substantial improvements in sensitivity, angular resolution, and frequency coverage beyond the current Karl G. Jansky Very Large Array (VLA). It will have a continuous frequency coverage of 1.2 GHz to 50 GHz and 70 to 116 GHz, and a total aperture 10 times more sensitive than the VLA (and 25 times more sensitive than a 34-m-diameter antenna of the Deep Space Network [DSN]). One of the key goals for the NAA is to reduce the operating costs without sacrificing performance. We are designing an ultra-wideband receiver package designed to operate across the 8 to 48 GHz frequency range in contrast to the current VLA, which covers this frequency range with five receiver packages. Reducing the number of receiving systems required to cover the full frequency range would reduce operating costs. To minimize implementation, operational, and maintenance costs, we are developing a receiver that is compact, simple to assemble, and that consumes less power. The objective of this work is to develop a prototype integrated feed-receiver package with a sensitivity performance comparable to current narrower-band systems on radio telescopes and the DSN, but with a design that meets the requirement of low long-term operational costs. The ultra-wideband receiver package consists of a feedhorn, low-noise amplifier (LNA), and downconverters to analog intermediate frequencies. Both the feedhorn and the LNA are cryogenically cooled. Key features of this design are a quad-ridge feedhorn with dielectric loading and a cryogenic receiver with a noise temperature of no more than 30°K at the low end of the band. In this article, we report on the status of this receiver package development, including the feed design and LNA implementation. We present simulation studies of the feed horn carried out to optimize illumination

  10. FDTD Computation of Human Eye Exposure to Ultra-wideband Electromagnetic Pulses

    CERN Document Server

    Simicevic, Neven

    2007-01-01

    With an increase in the application of ultra-wideband (UWB) electromagnetic pulses in the communications industry, radar, biotechnology and medicine, comes an interest in UWB exposure safety standards. Despite an increase of the scientific research on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. A numerical computational approach, such as a finite-difference time domain (FDTD) method, is required to visualize and understand the complexity of broadband electromagnetic interactions. The FDTD method has almost no limits in the description of the geometrical and dispersive properties of the simulated material, it is numerically robust and appropriate for current computer technology. In this paper, a complete calculation of exposure of the human eye to UWB electromagnetic pulses in the frequency range of 3.1-10.6, 22-29, and 57-64 GHz is performed. Computation in this frequency range required a geometrical resolution of the eye of $\\rm 0.1 \\: mm$ and an...

  11. A Subspace Approach to Blind Multiuser Detection for Ultra-Wideband Communication Systems

    Directory of Open Access Journals (Sweden)

    Liu Ping

    2005-01-01

    Full Text Available Impulse radio-based ultra-wideband (UWB communication systems allow multiple users to access channels simultaneously by assigning unique time-hopping codes to individual users, while each user's information stream is modulated by pulse-position modulation (PPM. However, transmitted signals undergo fading from a number of propagation paths in a dense multipath environment and meanwhile suffer from multiuser interference (MUI. Although RAKE receiver can be employed to maximally exploit path diversity, it is a single-user receiver. Multiuser receiver can significantly improve detection performance. Each of these receivers requires channel parameters. Existing maximum likelihood channel estimators treat MUI as Gaussian noise. In this paper, we derive a blind subspace channel estimator first and then design linear receivers. Following a channel input/output model that transforms a PPM signal into a sum of seemingly pulse-amplitude modulated signals, a structure similar to a code-division multiple-access (CDMA system is observed. Code matrices for each user are identified. After considering unique statistical properties of new inputs such as mean and covariance, the model is further transformed to ensure that all signature waveforms lie in the signal subspace and are orthogonal to the noise subspace. Consequently, a subspace technique is applicable to estimate each channel. Then minimum mean square error receivers of two different versions are designed, suitable for both uplink and downlink. Asymptotic performance of both the channel estimator and receivers is studied. Closed-form bit error rate is also derived.

  12. A VLSI Neural Monitoring System With Ultra-Wideband Telemetry for Awake Behaving Subjects.

    Science.gov (United States)

    Greenwald, E; Mollazadeh, M; Hu, C; Wei Tang; Culurciello, E; Thakor, V

    2011-04-01

    Long-term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for neuroscience and neuroengineering applications. Here, we present a miniature, lightweight, and low-power recording system for monitoring neural activity in awake behaving animals. The system integrates two custom designed very-large-scale integrated chips, a neural interface module fabricated in 0.5 μm complementary metal-oxide semiconductor technology and an ultra-wideband transmitter module fabricated in a 0.5 μm silicon-on-sapphire (SOS) technology. The system amplifies, filters, digitizes, and transmits 16 channels of neural data at a rate of 1 Mb/s. The entire system, which includes the VLSI circuits, a digital interface board, a battery, and a custom housing, is small and lightweight (24 g) and, thus, can be chronically mounted on small animals. The system consumes 4.8 mA and records continuously for up to 40 h powered by a 3.7-V, 200-mAh rechargeable lithium-ion battery. Experimental benchtop characterizations as well as in vivo multichannel neural recordings from awake behaving rats are presented here.

  13. Factors Affecting Image Quality in Near-field Ultra-wideband Radar Imaging for Biomedical Applications

    Science.gov (United States)

    Curtis, Charlotte

    Near-field ultra-wideband radar imaging has potential as a new breast imaging modality. While a number of reconstruction algorithms have been published with the goal of reducing undesired responses or clutter, an in-depth analysis of the dominant sources of clutter has not been conducted. In this thesis, time domain radar image reconstruction is demonstrated to be equivalent to frequency domain synthetic aperture radar. This reveals several assumptions inherent to the reconstruction algorithm related to radial spreading, point source antennas, and the independent summation of point scatterers. Each of these assumptions is examined in turn to determine which has the greatest impact on the resulting image quality and interpretation. In addition, issues related to heterogeneous and dispersive media are addressed. Variations in imaging parameters are tested by observing their influence on the system point spread function. Results are then confirmed by testing on simple and detailed simulation models, followed by data acquired from human volunteers. Recommended parameters are combined into a new imaging operator that is demonstrated to generate results comparable to a more accurate signal model, but with a 50 fold improvement in computational efficiency. Finally, the most significant factor affecting image quality is determined to be the estimate of tissue properties used to form the image.

  14. Performance Analysis of Ultra Wideband Receivers for High Data Rate Wireless Personal Area Network System

    Directory of Open Access Journals (Sweden)

    Bikramaditya Das

    2010-03-01

    Full Text Available For high data rate ultra wideband communication system, performance comparison of Rake, MMSE andRake-MMSE receivers is attempted in this paper. Further a detail study on Rake-MMSE time domainequalizers is carried out taking into account all the important parameters such as the effect of the numberof Rake fingers and equalizer taps on the error rate performance. This receiver combats inter-symbolinterference by taking advantages of both the Rake and equalizer structure. The bit error rateperformances are investigated using MATLAB simulation on IEEE 802.15.3a defined UWB channelmodels. Simulation results show that the bit error rate probability of Rake-MMSE receiver is much betterthan Rake receiver and MMSE equalizer. Study on non-line of sight indoor channel models illustratesthat bit error rate performance of Rake-MMSE (both LE and DFE improves for CM3 model with smallerspread compared to CM4 channel model. It is indicated that for a MMSE equalizer operating at low tomedium SNR values, the number of Rake fingers is the dominant factor to improve system performance,while at high SNR values the number of equalizer taps plays a more significant role in reducing the errorrate.

  15. Fiber-distributed Ultra-wideband noise radar with steerable power spectrum and colorless base station.

    Science.gov (United States)

    Zheng, Jianyu; Wang, Hui; Fu, Jianbin; Wei, Li; Pan, Shilong; Wang, Lixian; Liu, Jianguo; Zhu, Ninghua

    2014-03-10

    A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible.

  16. ON THE PAR REDUCTION OF MB-OFDM ULTRA-WIDEBAND SIGNALS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Peak to Average power Ratio (PAR) of a Multi-Band Orthogonal Frequency-Division Multi-plexing (MB-OFDM) Ultra-Wide Band (UWB) signals can be substantially larger than that of single carrieror carrier-less ultra-wideband signals. In this letter, a novel PAR reduction scheme for the MB-OFDM UWBsystem based on spreading and interleaving is proposed. By spreading the coded bits over each subcarrier incorresponding band and interleaving the spread symbols across all bands, the PAR statistics of theMB-OFDM signals can be improved and the PAR is reduced obviously. In the PAR reduction scheme, there isno loss in transmission data rate or Bit Error Rate (BER) performance decreasing. Since the spreading andinterleaving operation are implemented by unitary Hadamard sequences and used for an approach to providethe robustness of the UWB system to narrowband interference, there is no additional implementation burden.Simulation results show that the investigated scheme gives the PAR reduction of 3dB compared with that ofthe original MB-OFDM signals.

  17. Two-Step Time of Arrival Estimation for Pulse-Based Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    H. Vincent Poor

    2008-05-01

    Full Text Available In cooperative localization systems, wireless nodes need to exchange accurate position-related information such as time-of-arrival (TOA and angle-of-arrival (AOA, in order to obtain accurate location information. One alternative for providing accurate position-related information is to use ultra-wideband (UWB signals. The high time resolution of UWB signals presents a potential for very accurate positioning based on TOA estimation. However, it is challenging to realize very accurate positioning systems in practical scenarios, due to both complexity/cost constraints and adverse channel conditions such as multipath propagation. In this paper, a two-step TOA estimation algorithm is proposed for UWB systems in order to provide accurate TOA estimation under practical constraints. In order to speed up the estimation process, the first step estimates a coarse TOA of the received signal based on received signal energy. Then, in the second step, the arrival time of the first signal path is estimated by considering a hypothesis testing approach. The proposed scheme uses low-rate correlation outputs and is able to perform accurate TOA estimation in reasonable time intervals. The simulation results are presented to analyze the performance of the estimator.

  18. A mm-Wave 2D Ultra-Wideband Imaging Radar for Breast Cancer Detection

    Directory of Open Access Journals (Sweden)

    Stefano Moscato

    2013-01-01

    Full Text Available This paper presents the preliminary design of a mm-wave ultra-wideband (UWB radar for breast cancer detection. A mass screening of women for breast cancer is essential, as the early diagnosis of the tumour allows best treatment outcomes. A mm-wave UWB radar could be an innovative solution to achieve the high imaging resolution required without risks for the patient. The 20–40 GHz frequency band used in the system proposed in this work guarantees high cross/range resolution performances. The developed preliminary architecture employs two monomodal truncated double-ridge waveguides that act as antennas; these radiators are shifted by microstep actuators to form a synthetic linear aperture. The minimum antenna-to-antenna distance achievable, the width of the synthetic aperture, and the minimum frequency step determine the performance of the 2D imaging system. Measures are performed with a mm-wave vector network analyzer driven by an automatic routine, which controls also the antennas shifts. The scattering matrix is then calibrated and the delay-multiply-and-sum (DMAS algorithm is applied to elaborate a high-resolution 2D image of the targets. Experimental results show that 3 mm cross and 8 mm range resolutions were achieved, which is in line with theoretical expectations and promising for future developments.

  19. Compact Elliptically Tapered Slot Antenna with Non-uniform Corrugations for Ultra-wideband Applications

    Directory of Open Access Journals (Sweden)

    F. G. Zhu

    2013-04-01

    Full Text Available A small size elliptically tapered slot antenna (ETSA fed by coplanar waveguide (CPW for ultra-wideband (UWB applications is proposed. It is printed on an FR4 substrate and occupies a size of 37×34×0.8 mm^3. A pair of quarter circular shapes is etched on the radiator to reduce the size. To overcome the limitation of uniform corrugation, non-uniform corrugation is utilized to reduce the cross-polarization level. A parametric study is carried out to investigate the effects of circular cut and corrugations. In order to validate the design, a prototype is fabricated and measured. Both simulated and measured results confirm that the proposed antenna achieves a good performance of a reflection coefficient below -10 dB from 3.1 GHz to 10.6 GHz, including a maximum antenna gain of 8.1dBi, directional patterns in the end-fire direction, low cross-polarization level below -20 dB and linear phase response. The antenna is promising for applications in UWB impulse radar imaging.

  20. A Low Energy Consumption DOA Estimation Approach for Conformal Array in Ultra-Wideband

    Directory of Open Access Journals (Sweden)

    Liangtian Wan

    2013-12-01

    Full Text Available Most direction-of-arrival (DOA estimation approaches for conformal array suffer from high computational complexity, which cause high energy loss for the direction finding system. Thus, a low energy consumption DOA estimation algorithm for conformal array antenna is proposed in this paper. The arbitrary baseline direction finding algorithm is extended to estimate DOA for a conformal array in ultra-wideband. The rotation comparison method is adopted to solve the ambiguity of direction finding. The virtual baseline approach is used to construct the virtual elements. Theoretically, the virtual elements can be extended in the space flexibility. Four elements (both actual and virtual elements can be used to obtain a group of solutions. The space angle estimation can be obtained by using sub-array divided technique and matrix inversion method. The stability of the proposed algorithm can be guaranteed by averaging the angles obtained by different sub-arrays. Finally, the simulation results verify the effectiveness of the proposed method with high DOA estimation accuracy and relatively low computational complexity.

  1. Performance Analysis of Ultra Wideband Receivers for High Data Rate Wireless Personal Area Network System

    CERN Document Server

    Das, Bikramaditya; 10.5121/jgraphhoc.2010.2104

    2010-01-01

    For high data rate ultra wideband communication system, performance comparison of Rake, MMSE and Rake-MMSE receivers is attempted in this paper. Further a detail study on Rake-MMSE time domain equalizers is carried out taking into account all the important parameters such as the effect of the number of Rake fingers and equalizer taps on the error rate performance. This receiver combats inter-symbol interference by taking advantages of both the Rake and equalizer structure. The bit error rate performances are investigated using MATLAB simulation on IEEE 802.15.3a defined UWB channel models. Simulation results show that the bit error rate probability of Rake-MMSE receiver is much better than Rake receiver and MMSE equalizer. Study on non-line of sight indoor channel models illustrates that bit error rate performance of Rake-MMSE (both LE and DFE) improves for CM3 model with smaller spread compared to CM4 channel model. It is indicated that for a MMSE equalizer operating at low to medium SNR values, the number o...

  2. Low-sampling-rate ultra-wideband channel estimation using equivalent-time sampling

    KAUST Repository

    Ballal, Tarig

    2014-09-01

    In this paper, a low-sampling-rate scheme for ultra-wideband channel estimation is proposed. The scheme exploits multiple observations generated by transmitting multiple pulses. In the proposed scheme, P pulses are transmitted to produce channel impulse response estimates at a desired sampling rate, while the ADC samples at a rate that is P times slower. To avoid loss of fidelity, the number of sampling periods (based on the desired rate) in the inter-pulse interval is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this case, and to achieve an overall good channel estimation performance, without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. It is shown that this estimator is related to the Bayesian linear minimum mean squared error (LMMSE) estimator. Channel estimation performance of the proposed sub-sampling scheme combined with the new estimator is assessed in simulation. The results show that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in almost all cases, while in the high SNR regime it also outperforms the LMMSE estimator. In addition to channel estimation, a synchronization method is also proposed that utilizes the same pulse sequence used for channel estimation. © 2014 IEEE.

  3. Design of CMOS RFIC ultra-wideband impulse transmitters and receivers

    CERN Document Server

    Nguyen, Cam

    2017-01-01

    This book presents the design of ultra-wideband (UWB) impulse-based transmitter and receiver frontends, operating within the 3.1-10.6 GHz frequency band, using CMOS radio-frequency integrated-circuits (RFICs). CMOS RFICs are small, cheap, low power devices, better suited for direct integration with digital ICs as compared to those using III-V compound semiconductor devices. CMOS RFICs are thus very attractive for RF systems and, in fact, the principal choice for commercial wireless markets.  The book comprises seven chapters. The first chapter gives an introduction to UWB technology and outlines its suitability for high resolution sensing and high-rate, short-range ad-hoc networking and communications. The second chapter provides the basics of CMOS RFICs needed for the design of the UWB RFIC transmitter and receiver presented in this book. It includes the design fundamentals, lumped and distributed elements for RFIC, layout, post-layout simulation, and measurement. The third chapter discusses the basics of U...

  4. Human Respiration Rate Estimation Using Ultra-wideband Distributed Cognitive Radar System

    Institute of Scientific and Technical Information of China (English)

    Yifan Chen; Predrag Rapajic

    2008-01-01

    It has been shown that remote monitoring of pulmonary activity can be achieved using ultra-wideband (UWB) systems,which shows promise in home healthcare, rescue, and security applications. In this paper, we first present a multi-ray propagation model for UWB signal, which is traveling through the human thorax and is reflected on the air/dry-skin/fat/muscle interfaces. A geometry-based statistical channel model is then developed for simulating the reception of UWB signals in the indoor propagation environment. This model enables replication of time-varying multipath profiles due to the displacement of a human chest. Subsequently,a UWB distributed cognitive radar system (UWB-DCRS) is developed for the robust detection of chest cavity motion and the accurate estimation of respiration rate. The analytical framework can serve as a basis in the planning and evaluation of future measurement programs. We also provide a case study on how the antenna beamwidth affects the estimation of respiration rate based on the proposed propagation models and system architecture.

  5. Ultra-wideband circular-polarization converter with micro-split Jerusalem-cross metasurfaces

    Science.gov (United States)

    Gao, Xi; Yu, Xing-Yang; Cao, Wei-Ping; Jiang, Yan-Nan; Yu, Xin-Hua

    2016-12-01

    An ultrathin micro-split Jerusalem-cross metasurface is proposed in this paper, which can efficiently convert the linear polarization of electromagnetic (EM) wave into the circular polarization in ultra-wideband. By symmetrically employing two micro-splits on the horizontal arm (in the x direction) of the Jerusalem-cross structure, the bandwidth of the proposed device is significantly extended. Both simulated and experimental results show that the proposed metasurface is able to convert linearly polarized waves into circularly polarized waves in a frequency range from 12.4 GHz to 21 GHz, with an axis ratio better than 1 dB. The simulated results also show that such a broadband and high-performance are maintained over a wide range of incident angle. The presented polarization converter can be used in a number of areas, such as spectroscopy and wireless communications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61461016 and 61661012), the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant Nos. 2014GXNSFAA118366, 2014GXNSFAA118283, and 2015jjBB7002), and the Innovation Project of Graduate Education of Guilin University of Electronic Technology, China (Grant No. 2016YJCX82).

  6. Numerical Design of Ultra-Wideband Printed Antenna for Surface Penetrating Radar Application

    Directory of Open Access Journals (Sweden)

    Achmad Munir

    2011-08-01

    Full Text Available Surface penetrating radar (SPR is an imaging device of electromagnetic wave that works by emitting and transmitting a narrow period pulse through the antenna. Due to the use of narrow period pulse, according to the Fourier transform duality, therefore ultra-wideband (UWB antenna becomes one of the most important needs in SPR system. In this paper, a novel UWB printed antenna is proposed to be used for SPR application. Basically, the proposed antenna is developed from a rectangular microstrip antenna fed by symmetric T-shaped. Some investigation methods such as resistive loading, abrupt transition, and ground plane modification are attempted to achieve required characteristics of bandwidth, radiation efficiency, and compactness needed by the system. To obtain the optimum design, the characteristics of proposed antenna are numerically investigated through the physical parameters of antenna. It is shown that proposed antenna deployed on an FR-4 Epoxy substrate with permittivity of 4.3 and thickness of 1.6mm has a compact size of 72.8mm x 60.0mm and a large bandwidth of 50MHz-5GHz which is suitable for SPR application.

  7. Design and investigation of planar technology based ultra-wideband antenna with directional radiation patterns

    Science.gov (United States)

    Meena, M. L.; Parmar, Girish; Kumar, Mithilesh

    2016-03-01

    A novel design technique based on planar technology for ultra-wideband (UWB) antennas with different ground shape having directional radiation pattern is being presented here. Firstly, the L-shape corner reflector ground plane antenna is designed with microstrip feed line in order to achieve large bandwidth and directivity. Thereafter, for the further improvement in the directivity as well as for better impedance matching the parabolic-shape ground plane has been introduced. The coaxial feed line is given for the proposed directional antenna in order to achieve better impedance matching with 50 ohm transmission line. The simulation analysis of the antenna is done on CST Microwave Studio software using FR-4 substrate having thickness of 1.6 mm and dielectric constant of 4.4. The simulated result shows a good return loss (S11) with respect to -10 dB. The radiation pattern characteristic, angular width, directivity and bandwidth performance of the antenna have also been compared at different resonant frequencies. The designed antennas exhibit low cost, low reflection coefficient and better directivity in the UWB frequency band.

  8. Low-sampling-rate ultra-wideband channel estimation using a bounded-data-uncertainty approach

    KAUST Repository

    Ballal, Tarig

    2014-01-01

    This paper proposes a low-sampling-rate scheme for ultra-wideband channel estimation. In the proposed scheme, P pulses are transmitted to produce P observations. These observations are exploited to produce channel impulse response estimates at a desired sampling rate, while the ADC operates at a rate that is P times less. To avoid loss of fidelity, the interpulse interval, given in units of sampling periods of the desired rate, is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this situation and to achieve good performance without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. This estimator is shown to be related to the Bayesian linear minimum mean squared error (LMMSE) estimator. The performance of the proposed sub-sampling scheme was tested in conjunction with the new estimator. It is shown that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in most cases; while in the high SNR regime, it also outperforms the LMMSE estimator. © 2014 IEEE.

  9. Interference Mitigation between Ultra-Wideband Sensor Network and Other Legal Systems

    Directory of Open Access Journals (Sweden)

    Bin Li

    2010-01-01

    Full Text Available Ultra-wideband impulse radio (UWB-IR sensor network has intensive military and commercial applications. However, the interference between UWB and other existed networks should be casually investigated. In this paper, we consider interference mitigation in UWB sensors in the context of cognitive radio (CR. Firstly, we suggest a general state transition model to characterize the working states evolution of legal networks, also referred to as primary users (PU. Spectrum sensing, used to identify the state of PU, is formulated as detection of a corresponding state sequence. Maximum posterior probability (MAP criterion is adopted to perform spectrum sensing. By exploring potential gain of state transitions, detection probability for nearby networks is improved significantly. Subsequently, based on the radius basis function neural network (RBF, we present a novel spectrum sculptor to design UWB waveforms. Attributed to the excellent reconfiguration of RBF, our scheme can produce UWB waveforms tracing available spectrums. The designed waveforms can entirely utilize multiple unoccupied bands to maintain uninterrupted communications. Also, sufficient spectral attenuation can be generated in specific bands to mitigate mutual interference between UWB sensors and other networks. Besides, orthogonal waveforms can be easily derived, which either improves transmission performance or provides a flexible accessing strategy for UWB sensors.

  10. Study of imaging radar using ultra-wideband microwave-modulated infrared laser

    Science.gov (United States)

    Mase, Atsushi; Kogi, Yuichiro; Ikezi, Hiroyuki; Inutake, Masaaki; Wang, Xiaolong

    2016-09-01

    In this paper, we present an ultra-wideband microwave-modulated laser radar which is designed and fabricated for improvement of the spatial resolution both in the range direction and the azimuth direction. The amplitude modulation in a range of 0.01-18 GHz is applied to an infrared laser source of 1550 nm wavelength. The frequency and the bandwidth are assigned by the Administration of Radio under the Ministry of Internal Affairs and Communications in Japan. However, there is no bandwidth limitation in the infrared region. Considering the influence of radiation pattern for microwave antennas case, there is no side lobe in laser beam transmission. Ambiguous signal and interferences which are returned from the ground can be suppressed. A prototype of laser-radar system with a fiber collimator for both transmitting and receiving optics has been fabricated. A vector network analyzer is used to obtain S21 signal between the microwave modulation input and that of received signal. The system is, at first, applied to the measurement of the distance (position) of an object. It is proved that the spatial resolution is less than 1 cm during 5-10 m. As an initial experiment, we have succeeded to obtain 3D image of object by scanning a laser beam in two dimensions.

  11. Jitter-Robust Orthogonal Hermite Pulses for Ultra-Wideband Impulse Radio Communications

    Directory of Open Access Journals (Sweden)

    Ryuji Kohno

    2005-03-01

    Full Text Available The design of a class of jitter-robust, Hermite polynomial-based, orthogonal pulses for ultra-wideband impulse radio (UWB-IR communications systems is presented. A unified and exact closed-form expression of the auto- and cross-correlation functions of Hermite pulses is provided. Under the assumption that jitter values are sufficiently smaller than pulse widths, this formula is used to decompose jitter-shifted pulses over an orthonormal basis of the Hermite space. For any given jitter probability density function (pdf, the decomposition yields an equivalent distribution of N-by-N matrices which simplifies the convolutional jitter channel model onto a multiplicative matrix model. The design of jitter-robust orthogonal pulses is then transformed into a generalized eigendecomposition problem whose solution is obtained with a Jacobi-like simultaneous diagonalization algorithm applied over a subset of samples of the channel matrix distribution. Examples of the waveforms obtained with the proposed design and their improved auto- and cross-correlation functions are given. Simulation results are presented, which demonstrate the superior performance of a pulse-shape modulated (PSM- UWB-IR system using the proposed pulses, over the same system using conventional orthogonal Hermite pulses, in jitter channels with additive white Gaussian noise (AWGN.

  12. Pulse Sign Separation Technique for the Received Bits in Wireless Ultra-Wideband Combination Approach

    Directory of Open Access Journals (Sweden)

    Rashid A. Fayadh

    2014-01-01

    Full Text Available When receiving high data rate in ultra-wideband (UWB technology, many users have experienced multiple-user interference and intersymbol interference in the multipath reception technique. Structures have been proposed for implementing rake receivers to enhance their capabilities by reducing the bit error probability (Pe, thereby providing better performances by indoor and outdoor multipath receivers. As a result, several rake structures have been proposed in the past to reduce the number of resolvable paths that must be estimated and combined. To achieve this aim, we suggest two maximal ratio combiners based on the pulse sign separation technique, such as the pulse sign separation selective combiner (PSS-SC and the pulse sign separation partial combiner (PSS-PC to reduce complexity with fewer fingers and to improve the system performance. In the combiners, a comparator was added to compare the positive quantity of positive pulses and negative quantities of negative pulses to decide whether the transmitted bit was 1 or 0. The Pe was driven by simulation for multipath environments for impulse radio time-hopping binary phase shift keying (TH-BPSK modulation, and the results were compared with those of conventional selective combiners (C-SCs and conventional partial combiners (C-PCs.

  13. Design and investigation of planar technology based ultra-wideband antenna with directional radiation patterns

    Energy Technology Data Exchange (ETDEWEB)

    Meena, M. L., E-mail: madan.meena.ece@gamil.com; Parmar, Girish, E-mail: girish-parmar2002@yahoo.com; Kumar, Mithilesh, E-mail: mith-kr@yahoo.com [Department of Electronics Engineering, Rajasthan Technical University, Kota (India)

    2016-03-09

    A novel design technique based on planar technology for ultra-wideband (UWB) antennas with different ground shape having directional radiation pattern is being presented here. Firstly, the L-shape corner reflector ground plane antenna is designed with microstrip feed line in order to achieve large bandwidth and directivity. Thereafter, for the further improvement in the directivity as well as for better impedance matching the parabolic-shape ground plane has been introduced. The coaxial feed line is given for the proposed directional antenna in order to achieve better impedance matching with 50 ohm transmission line. The simulation analysis of the antenna is done on CST Microwave Studio software using FR-4 substrate having thickness of 1.6 mm and dielectric constant of 4.4. The simulated result shows a good return loss (S11) with respect to -10 dB. The radiation pattern characteristic, angular width, directivity and bandwidth performance of the antenna have also been compared at different resonant frequencies. The designed antennas exhibit low cost, low reflection coefficient and better directivity in the UWB frequency band.

  14. Conformal and Spectrally Agile Ultra Wideband Phased Array Antenna for Communication and Sensing

    Science.gov (United States)

    Novak, M.; Alwan, Elias; Miranda, Felix; Volakis, John

    2015-01-01

    There is a continuing need for reducing size and weight of satellite systems, and is also strong interest to increase the functional role of small- and nano-satellites (for instance SmallSats and CubeSats). To this end, a family of arrays is presented, demonstrating ultra-wideband operation across the numerous satellite communications and sensing frequencies up to the Ku-, Ka-, and Millimeter-Wave bands. An example design is demonstrated to operate from 3.5-18.5 GHz with VSWR2 at broadside, and validated through fabrication of an 8 x 8 prototype. This design is optimized for low cost, using Printed Circuit Board (PCB) fabrication. With the same fabrication technology, scaling is shown to be feasible up to a 9-49 GHz band. Further designs are discussed, which extend this wideband operation beyond the Ka-band, for instance from 20-80 GHz. Finally we will discuss recent efforts in the direct integration of such arrays with digital beamforming back-ends. It will be shown that using a novel on-site coding architecture, orders of magnitude reduction in hardware size, power, and cost is accomplished in this transceiver.

  15. Accurate Permittivity Measurements for Microwave Imaging via Ultra-Wideband Removal of Spurious Reflectors

    Directory of Open Access Journals (Sweden)

    Mathew G. Pelletier

    2010-09-01

    Full Text Available The use of microwave imaging is becoming more prevalent for detection of interior hidden defects in manufactured and packaged materials. In applications for detection of hidden moisture, microwave tomography can be used to image the material and then perform an inverse calculation to derive an estimate of the variability of the hidden material, such internal moisture, thereby alerting personnel to damaging levels of the hidden moisture before material degradation occurs. One impediment to this type of imaging occurs with nearby objects create strong reflections that create destructive and constructive interference, at the receiver, as the material is conveyed past the imaging antenna array. In an effort to remove the influence of the reflectors, such as metal bale ties, research was conducted to develop an algorithm for removal of the influence of the local proximity reflectors from the microwave images. This research effort produced a technique, based upon the use of ultra-wideband signals, for the removal of spurious reflections created by local proximity reflectors. This improvement enables accurate microwave measurements of moisture in such products as cotton bales, as well as other physical properties such as density or material composition. The proposed algorithm was shown to reduce errors by a 4:1 ratio and is an enabling technology for imaging applications in the presence of metal bale ties.

  16. Ultra-Wideband Sensors for Improved Magnetic Resonance Imaging, Cardiovascular Monitoring and Tumour Diagnostics

    Directory of Open Access Journals (Sweden)

    Frank Seifert

    2010-12-01

    Full Text Available The specific advantages of ultra-wideband electromagnetic remote sensing (UWB radar make it a particularly attractive technique for biomedical applications. We partially review our activities in utilizing this novel approach for the benefit of high and ultra-high field magnetic resonance imaging (MRI and other applications, e.g., for intensive care medicine and biomedical research. We could show that our approach is beneficial for applications like motion tracking for high resolution brain imaging due to the non-contact acquisition of involuntary head motions with high spatial resolution, navigation for cardiac MRI due to our interpretation of the detected physiological mechanical contraction of the heart muscle and for MR safety, since we have investigated the influence of high static magnetic fields on myocardial mechanics. From our findings we could conclude, that UWB radar can serve as a navigator technique for high and ultra-high field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard ECG analysis by complementary information where sole ECG analysis fails. Further analytical investigations have proven the feasibility of this method for intracranial displacements detection and the rendition of a tumour’s contrast agent based perfusion dynamic. Beside these analytical approaches we have carried out FDTD simulations of a complex arrangement mimicking the illumination of a human torso model incorporating the geometry of the antennas applied.

  17. An ultra-wideband pattern reconfigurable antenna based on graphene coating

    Science.gov (United States)

    Jiang, YanNan; Yuan, Rui; Gao, Xi; Wang, Jiao; Li, SiMin; Lin, Yi-Yu

    2016-11-01

    An ultra-wideband pattern reconfigurable antenna is proposed. The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating. It consists of a graphene sheet coated onto the inner surface of a cylindrical substrate and a set of independent polysilicon DC gating pads mounted on the outside of the cylindrical substrate. By changing the DC bias voltages to the different gating pads, the surface impedance of the graphene coating can be freely controlled. Due to the tunability of graphene's surface impedance, the radiation pattern of the proposed antenna can be reconfigured. A transmission line method is used to illustrate the physical mechanism of the proposed antenna. The results show that the proposed antenna can reconfigure its radiation pattern in the omnidirectional mode with the relative bandwidth of 58.5% and the directional mode over the entire azimuth plane with the relative bandwidth of 67%. Project supported by the National Natural Science Foundation of China (Grant Nos. 61661012, 61461016, and 61361005), the Natural Science Foundation of Guangxi, China (Grant Nos. 2015GXNSFBB139003 and 2014GXNSFAA118283), Program for Innovation Research Team of Guilin University of Electromagnetic Technology, China, and the Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing, China.

  18. Threshold Selection for Ultra-Wideband TOA Estimation based on Neural Networks

    Directory of Open Access Journals (Sweden)

    Xue-rong Cui

    2012-09-01

    Full Text Available Because of the good penetration into many common materials and inherent fine resolution, Ultra-Wideband (UWB signals are widely used in remote ranging and positioning applications. On the other hand, because of the high sampling rate, coherent Time of Arrival (TOA estimation algorithms are not practical for low cost, low complexity UWB systems. In order to improve the precision of TOA estimation, an Energy Detection (ED based non-coherent TOA estimation algorithm using Artificial Neural Networks (ANN is presented which is based on the skewness after energy detection. The expected values of skewness and kurtosis with respect to the Signal to Noise Ratio (SNR are investigated. It is shown that the skewness is more suitable for TOA estimation. The best threshold values for different SNRs are investigated and the effects of integration period and channel modes are examined. Comparisons with other ED based algorithms show that in CM1 and CM2 channels, the proposed algorithm provides higher precision and robustness in both high and low SNR environments.

  19. Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide

    Science.gov (United States)

    Xiao, Binggang; Kong, Sheng; Xiao, Sanshui

    2016-09-01

    Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN and satellite communication interference simultaneously. Both the cutoff frequency and the notch frequency are sensitive to the structure parameters, and the cut-off frequency can reach 20 GHz. An adiabatic transition relying on gradient hole-size and flaring ground is designed to effectively couple energy into spoof SPP waveguide. The result shows its cut-off frequency of 17.4 GHz with the insertion loss better than 3 dB during the whole pass-band, while having more than 20 dB rejections at 5.36 GHz and 9.32 GHz with 10 dB fractional bandwidth 1.07% and 0.74% respectively to avoid the existing WLAN and satellite communication signals. Due to planar structures proposed here, it is easy to integrate in the microwave integrated systems, which can play an important role in the microwave communication circuit and system.

  20. Ultra-wideband, Wide Angle and Polarization-insensitive Specular Reflection Reduction by Metasurface based on Parameter-adjustable Meta-Atoms

    Science.gov (United States)

    Su, Jianxun; Lu, Yao; Zhang, Hui; Li, Zengrui; (Lamar) Yang, Yaoqing; Che, Yongxing; Qi, Kainan

    2017-02-01

    In this paper, an ultra-wideband, wide angle and polarization-insensitive metasurface is designed, fabricated, and characterized for suppressing the specular electromagnetic wave reflection or backward radar cross section (RCS). Square ring structure is chosen as the basic meta-atoms. A new physical mechanism based on size adjustment of the basic meta-atoms is proposed for ultra-wideband manipulation of electromagnetic (EM) waves. Based on hybrid array pattern synthesis (APS) and particle swarm optimization (PSO) algorithm, the selection and distribution of the basic meta-atoms are optimized simultaneously to obtain the ultra-wideband diffusion scattering patterns. The metasurface can achieve an excellent RCS reduction in an ultra-wide frequency range under x- and y-polarized normal incidences. The new proposed mechanism greatly extends the bandwidth of RCS reduction. The simulation and experiment results show the metasurface can achieve ultra-wideband and polarization-insensitive specular reflection reduction for both normal and wide-angle incidences. The proposed methodology opens up a new route for realizing ultra-wideband diffusion scattering of EM wave, which is important for stealth and other microwave applications in the future.

  1. Design of Vivaldi Microstrip Antenna for Ultra-Wideband Radar Applications

    Science.gov (United States)

    Perdana, M. Y.; Hariyadi, T.; Wahyu, Y.

    2017-03-01

    The development of radar technology has an important role in several fields such as aviation, civil engineering, geology, and medicine. One of the essential components of the radar system is the antenna. The bandwidth can specify the resolution of the radar. The wider the bandwidth, the higher the resolution of radar. For Ground penetrating radar (GPR) or medical applications need with a high-resolution radar so it needs an antenna with a wide bandwidth. In addition, for the radar application is required antenna with directional radiation pattern. So, we need an antenna with wide bandwidth and directional radiation pattern. One of antenna that has meet with these characteristics is vivaldi antenna. In previous research, has designed several vivaldi microstrip antenna for ultra-wideband radar applications which has a working frequency of 3.1 to 10.7 GHz. However, these studies there is still a shortage of one of them is the radiation pattern from lowest to highest frequency radiation pattern is not uniform in the sense that not all directional. Besides the antenna material used is also not easily available and the price is not cheap. This paper will discuss the design of a vivaldi microstrip antenna which has a wide bandwidth with directional radiation pattern works on 3.1 to 10.7 GHz and using cheaper substrate. Substrates used for vivaldi microstrip antenna vivaldi is FR4 with a dielectric constant of 4.3 and a thickness of 1.6 mm. Based on the simulation results we obtained that the antenna design has frequency range 3.1-10.7 GHz for return loss less than -10 dB with a directional radiation pattern. This antenna gain is 4.8 to 8 dBi with the largest dimension is 50 mm x 40 mm.

  2. A technique for the generation of customizable ultra-wideband pseudo-noise waveforms

    Science.gov (United States)

    Vela, Russell; Erisman, David; Narayanan, Ram M.

    2011-06-01

    Noise excitation sources in radar systems have become increasingly useful in applications requiring wideband spectral responses and covertness. However, in applications requiring spectral controllability, traditional analog noise sources prove troublesome and require additional hardware such as sets of digital filters whose own spectral characteristics must also be accounted for. In an effort to reduce these issues and increase the applications of noise waveforms, a technique for generating a fully controllable pseudo-noise waveform is presented. This pseudo-noise waveform will be generated through the use of a multi-tone waveform. By randomizing the phase angles and setting the appropriate amplitudes to the individual tones, the result is a waveform whose temporal pattern resembles noise and frequency response is broadband. The capabilities of this digitally produced pseudo-noise multi-tone waveform is presented by optimization via a water-filling technique, thereby producing a flat spectral response for a user defined amplitude, effectively removing the spectral effects of the radar components. This optimized waveform is used to present methods for increasing signal to noise ratio (SNR) of cross-correlated responses of the waveform through the application of window functions to the waveform. As a whole, this paper showcases the ability to use this pseudo-noise multi-tone waveform for complete ultra-wideband (UWB) spectral control through water-filling and a method for increasing SNR of the cross correlated response of the transmitted and received radar waveform for a bandwidth of 2.5 GHz ranging from 2 to 4.5 GHz.

  3. Photonic Ultra-Wideband 781.25-Mb/s Signal Generation and Transmission Incorporating Digital Signal Processing Detection

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

    2009-01-01

    The generation of photonic ultra-wideband (UWB) impulse signals using an uncooled distributed-feedback laser is proposed. For the first time, we experimentally demonstrate bit-for-bit digital signal processing (DSP) bit-error-rate measurements for transmission of a 781.25-Mb/s photonic UWB signal...... over fiber links. The DSP algorithm is described, the generated UWB signal is shown to comply with the U. S. Federal Communications Commission requirements, and transmission of 1.71 x 10(5) UWB bits over fiber is demonstrated without error....

  4. Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    Science.gov (United States)

    2008-10-16

    stimulated by increasing demands for automation in home and industrial areas, have triggered tremendous interests in the wireless sensor network (WSN...integration interval [17,25,35,36]. A practical implementation of a smart integrator is to control the integrator’s on-duration. Denoted by Hf, the symbol...Zhix(mTs-iTh) i=0 = 4>x, x(r)dr ( 5g ) where 4> is a quasi — Toeplitz matrix and 30 CHAPTER 5. A COMPRESSED SENSING BASED ULTRA- WIDEBAND

  5. Modelling and validation of a simple and compact wide upper stop band ultra-wideband bandpass filter

    Directory of Open Access Journals (Sweden)

    Somdotta Roy Choudhury

    2014-09-01

    Full Text Available A compact ultra-wideband (UWB bandpass filter (BPF is proposed based on end coupled microstrip transmission line, defected ground structure and defected microstrip structure. The experimental filter shows a fractional bandwidth of 110% at a centre frequency, with two observable transmission zeros (attenuation poles at 2.1 and 11.7 GHz. Measured results exhibit an UWB passband from 3.02 to 10.6 GHz with mid-band insertion loss of 1.8 dB and group delay variation <0.45 ns. The BPF achieves a wide stopband with < −18 dB attenuation up to 20 GHz.

  6. 超宽带平面天线研究进展%Progress in ultra-wideband planar antennas

    Institute of Scientific and Technical Information of China (English)

    钟顺时; 梁仙灵

    2007-01-01

    This paper introduces the advances of ultra-wideband (UWB) and super-wideband (SWB) planar antennas based on the printed monopole, microstrip slot and other planar antenna designs in the last decade. A brief history of the ultrawideband antennas is first provided. Several types of planar antennas for UWB systems with band-notched designs are reviewed. Special SWB planar antenna designs with the bandwidth ratio greater than 10:1 including metal-plate and printed monopole antennas and tapered slot antennas are presented and compared.

  7. Ultra-Wideband Radars for Measurements over Land and Sea Ice

    Science.gov (United States)

    Gogineni, S.; Hale, R.; Miller, H. G.; Yan, S.; Rodriguez-Morales, F.; Leuschen, C.; Wang, Z.; Gomez-Garcia, D.; Binder, T.; Steinhage, D.; Gehrmann, M.; Braaten, D. A.

    2015-12-01

    We developed two ultra-wideband (UWB) radars for measurements over the ice sheets in Greenland and Antarctica and sea ice. One of the UWB radars operates over a 150-600 MHz frequency range with a large, cross-track 24-element array. It is designed to sound ice, image the ice-bed interface, and map internal layers with fine resolution. The 24-element array consists of three 8-element sub-arrays. One of these sub-arrays is mounted under the fuselage of a BT-67 aircraft; the other two are mounted under the wings. The polarization of each antenna element can be individually reconfigured depending on the target of interest. The measured inflight VSWR is less than 2 over the operating range. The fuselage sub-array is used both for transmission and reception, and the wing-mounted sub-arrays are used for reception. The transmitter consists of an 8-channel digital waveform generator to synthesize chirped pulses of selectable pulse width, duration, and bandwidth. It also consists of drivers and power amplifiers to increase the power level of each individual channel to about 1 kW and a fast high-power transmit/receive switch. Each receiver consists of a limiter, switches, low-noise and driver amplifiers, and filters to shape and amplify received signals to the level required for digitization. The digital sub-section consists of timing and control sub-systems and 24 14-bit A/D converters to digitize received signals at a rate of 1.6 GSPS. The radar performance is evaluated using an optical delay line to simulate returns from about 2 km thick ice, and the measured radar loop sensitivity is about 215 dB. The other UWB microwave radar operates over a 2-18 GHz frequency range in Frequency-Modulated Continuous Wave (FM-CW) mode. It is designed to sound more than 1 m of snow over sea ice and map internal layers to a depth about 25-40 m in polar firn and ice. We operated the microwave radar over snow-covered sea ice and mapped snow as thin as 5 cm and as thick as 60 cm. We mapped

  8. Model-based sub-Nyquist sampling and reconstruction technique for ultra-wideband (UWB) radar

    Science.gov (United States)

    Nguyen, Lam; Tran, Trac D.

    2010-04-01

    The Army Research Lab has recently developed an ultra-wideband (UWB) synthetic aperture radar (SAR). The radar has been employed to support proof-of-concept demonstration for several concealed target detection programs. The radar transmits and receives short impulses to achieve a wide-bandwidth from 300 MHz to 3000 MHz. Since the radar directly digitizes the wide-bandwidth receive signals, the challenges is to how to employ relatively slow and inexpensive analog-to-digital (A/D) converters to sample the signals with a rate that is greater than the minimum Nyquist rate. ARL has developed a sampling technique that allows us to employ inexpensive A/D converters (ADC) to digitize the widebandwidth signals. However, this technique still has a major drawback due to the longer time required to complete a data acquisition cycle. This in turn translates to lower average power and lower effective pulse repetition frequency (PRF). Compressed Sensing (CS) theory offers a new approach in data acquisition. From the CS framework, we can reconstruct certain signals or images from much fewer samples than the traditional sampling methods, provided that the signals are sparse in certain domains. However, while the CS framework offers the data compression feature, it still does not address the above mentioned drawback, that is the data acquisition must be operated in equivalent time since many global measurements (obtained from global random projections) are required as depicted by the sensing matrix Φ in the CS framework. In this paper, we propose a new technique that allows the sub-Nyquist sampling and the reconstruction of the wide-bandwidth data. In this technique, each wide-bandwidth radar data record is modeled as a superposition of many backscatter signals from reflective point targets. The technique is based on direct sparse recovery using a special dictionary containing many time-delayed versions of the transmitted probing signal. We demonstrate via simulated as well as

  9. Millimeter-wave silicon-based ultra-wideband automotive radar transceivers

    Science.gov (United States)

    Jain, Vipul

    Since the invention of the integrated circuit, the semiconductor industry has revolutionized the world in ways no one had ever anticipated. With the advent of silicon technologies, consumer electronics became light-weight and affordable and paved the way for an Information-Communication-Entertainment age. While silicon almost completely replaced compound semiconductors from these markets, it has been unable to compete in areas with more stringent requirements due to technology limitations. One of these areas is automotive radar sensors, which will enable next-generation collision-warning systems in automobiles. A low-cost implementation is absolutely essential for widespread use of these systems, which leads us to the subject of this dissertation---silicon-based solutions for automotive radars. This dissertation presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors. The first CMOS 22-29-GHz pulse-radar receiver front-end for ultra-wideband radars is presented. The chip includes a low noise amplifier, I/Q mixers, quadrature voltage-controlled oscillators, pulse formers and variable-gain amplifiers. Fabricated in 0.18-mum CMOS, the receiver achieves a conversion gain of 35-38.1 dB and a noise figure of 5.5-7.4 dB. Integration of multi-mode multi-band transceivers on a single chip will enable next-generation low-cost automotive radar sensors. Two highly-integrated silicon ICs are designed in a 0.18-mum BiCMOS technology. These designs are also the first reported demonstrations of mm-wave circuits with high-speed digital circuits on the same chip. The first mm-wave dual-band frequency synthesizer and transceiver, operating in the 24-GHz and 77-GHz bands, are demonstrated. All

  10. 4 Gbps Impulse Radio (IR) Ultra-Wideband (UWB) Transmission over 100 Meters Multi Mode Fiber with 4 Meters Wireless Transmission

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Rodes Lopez, Roberto; Caballero Jambrina, Antonio

    2009-01-01

    We present experimental demonstrations of in-building impulse radio (IR) ultra-wideband (UWB) link consisting of 100 m multi mode fiber (MMF) and 4 m wireless transmission at a record 4 Gbps, and a record 8 m wireless transmission at 2.5 Gbps. A directly modulated vertical cavity surface emitting...

  11. 3.125 Gb/s impulse radio ultra-wideband photonic generation and distribution Over a 50 km Fiber With Wireless Transmission

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Yu, Xianbin; Gamatham, Romeo;

    2010-01-01

    A 3.125 Gb/s photonic impulse radio ultra-wideband signal is created using the incoherent optical field summation resulting from the cross gain modulation of an uncooled distributed feedback laser injected with an external cavity laser. After 50 km of fiber and wireless transmission over 2.9-3.3-m...

  12. Ultra Wideband Polarization-Selective Conversions of Electromagnetic Waves by Metasurface under Large-Range Incident Angles

    Science.gov (United States)

    Yin, Jia Yuan; Wan, Xiang; Zhang, Qian; Cui, Tie Jun

    2015-07-01

    We propose an ultra-wideband polarization-conversion metasurface with polarization selective and incident-angle insensitive characteristics using anchor-shaped units through multiple resonances. The broadband characteristic is optimized by the genetic optimization algorithm, from which the anchor-shaped unit cell generates five resonances, resulting in expansion of the operating frequency range. Owing to the structural feature of the proposed metasurface, only x- and y-polarized incident waves can reach high-efficiency polarization conversions, realizing the polarization-selective property. The proposed metasurface is also insensitive to the angle of incident waves, which indicates a promising future in modern communication systems. We fabricate and measure the proposed metasurface, and both the simulated and measured results show ultra-wide bandwidth for the x- and y-polarized incident waves.

  13. Experimental Analysis of 60-GHz VCSEL and ECL Photonic Generation and Transmission of Impulse-Radio Ultra-Wideband Signals

    DEFF Research Database (Denmark)

    Beltran, Marta; Jensen, Jesper Bevensee; Llorente, Roberto

    2011-01-01

    Optical generation of impulse-radio ultra-wideband (UWB) signals in the 60-GHz band is proposed and experimentally demonstrated. External-cavity laser (ECL) and vertical-cavity surface-emitting laser (VCSEL) is employed for frequency up-conversion by heterodyne mixing with a UWB optical signal...... for comparison purposes. Real-time bit-error-rate (BER) performance of generated signals at 3.125 Gb/s is evaluated combining fiber and 2-m wireless transmission. Different optical fiber types including 1-km bend-insensitive single-mode fiber and 20-km nonzero dispersion-shifted fiber is evaluated. $\\hbox......{BER} for the ECL and $\\hbox{BER} for the VCSEL requiring higher received optical power than the ECL is demonstrated employing electrical power detection....

  14. Outage Analysis of Ultra-Wideband System in Lognormal Multipath Fading and Square-Shaped Cellular Configurations

    Directory of Open Access Journals (Sweden)

    Pirinen Pekka

    2006-01-01

    Full Text Available Generic ultra-wideband (UWB spread-spectrum system performance is evaluated in centralized and distributed spatial topologies comprising square-shaped indoor cells. Statistical distributions for link distances in single-cell and multicell configurations are derived. Cochannel-interference-induced outage probability is used as a performance measure. The probability of outage varies depending on the spatial distribution statistics of users (link distances, propagation characteristics, user activities, and receiver settings. Lognormal fading in each channel path is incorporated in the model, where power sums of multiple lognormal signal components are approximated by a Fenton-Wilkinson approach. Outage performance of different spatial configurations is outlined numerically. Numerical results show the strong dependence of outage probability on the link distance distributions, number of rake fingers, and path losses.

  15. Ultra-Wideband Indoor Channel Modelling Using Ray-Tracing Software for through-the-Wall Imaging Radar

    Directory of Open Access Journals (Sweden)

    Christophe Lièbe

    2010-01-01

    Full Text Available This paper presents a new software for design of through-the-wall imaging radars. The first part describes the evolution of a ray tracing simulator, originally designed for propagation of narrowband signals, and then for ultra-wideband signals. This simulator allows to obtain temporal channel response to a wide-band emitter (3 GHz to 10 GHz. An experimental method is also described to identify the propagation paths. Simulation results are compared to propagation experiments under the same conditions. Different configurations are tested and then discussed. Finally, a configuration of through-the-wall imaging radar is proposed, with different antennas patterns and different targets. Simulated images will be helpful for understanding the experiment obtained images.

  16. Performance Analysis of the Multiband Orthogonal Frequency Division Multiplexing Ultra-Wideband Systems for Multipath Fading and Multiuser Interference Channels

    Directory of Open Access Journals (Sweden)

    Yuan Ouyang

    2015-01-01

    Full Text Available This paper presents the performance analysis of the multiband orthogonal frequency division multiplexing (MB-OFDM ultra-wideband (UWB systems for multipath fading and multiuser interference channels. A closed form approximation of the BER performance of the MB-OFDM UWB system with multiple interferences is proposed. Based on the derived approximation, the effects on the BER performance for the choice of the codeword constraint lengths of the convolutional encoder, the length of the cyclic prefix, and the multiuser environments of two or more interferers are thoroughly discussed. Four UWB multipath fading channels are also investigated for the BER performance of the MB-OFDM UWB system. The simulated results provide us with useful information to appropriately choose the parameters of the MB-OFDM UWB system for the sake of achieving the BER performance that conforms to requirement of the FCC standards.

  17. Performance Analysis of Ultra-Wideband Channel for Short-Range Monopulse Radar at Ka-Band

    Directory of Open Access Journals (Sweden)

    Naohiko Iwakiri

    2012-01-01

    Full Text Available High-range resolution is inherently provided with Ka-band ultra-wideband (UWB vehicular radars. The authors have developed a prototype UWB monopulse radar equipped with a two-element receiving antenna array and reported its measurement results. In this paper, a more detailed verification using these measurements is presented. The measurements were analyzed employing matched filtering and eigendecomposition, and then multipath components were extracted to examine the behavior of received UWB monopulse signals. Next, conventional direction finding algorithms based on narrowband assumption were evaluated using the extracted multipath components, resulting in acceptable angle-of-arrival (AOA from the UWB monopulse signal regardless of wideband signals. Performance degradation due to a number of averaging the received monopulses was also examined to design suitable radar's waveforms.

  18. System Wide Implementation of Photonically Generated Impulse Radio Ultra-Wideband for Gigabit Fiber-Wireless Access

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Rodes Lopez, Roberto

    2013-01-01

    radio ultra-wideband (IR-UWB) signals at 781.25 Mbps with on-off keying (OOK) and binary phase shift keying (BPSK) modulation formats. We further advance the state-of-the-art to include multi-Gigabit IR-UWB signal generation. Both OOK and BPSK signals comply with the Federal Communications Commission......-of-the-art electronic generation method in terms of transmission bit-error rate performance. Moreover, photonic IR-UWB generation is shown to be capable of longer wireless reach due to its lower bandwidth limitation. Finally, we experimentally demonstrate the integration of a relaxation oscillations-based UWB photonic...... generation system into existing wavelength division multiplexing passive optical networks (WDM-PON) infrastructure. This provides converged Gigabit indoor wireless and wireline access services....

  19. Target detection and reconstruction for compressive multiple-input, multiple-output ultra-wideband noise radar imaging

    Science.gov (United States)

    Kwon, Yangsoo; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2013-04-01

    We propose a sample selection method for multiple-input, multiple-output ultra-wideband noise radar imaging using compressive sensing. The proposed sample selection is based on comparing the norm values of candidates among the potential received signal and selecting the largest M samples among N per antenna to obtain selection diversity. Moreover, we propose an adaptive weighting allocation that improves reconstruction accuracy of compressive sensing by maximizing the mutual information between target echoes and transmitted signals. This weighting scheme is applicable to both sample selection schemes, a conventional random sampling and the proposed selection. Further, the weighting allocation with the knowledge of recovery error is proposed for more practical scenarios. Simulations show that the proposed selection and weighting allocation enhance multiple target detection probability and reduce normalized mean square error.

  20. Principle and experimental results of ultra-wideband noise radar imaging of a cylindrical conducting object using diffraction tomography

    Science.gov (United States)

    Shin, Hee Jung; Asmuth, Mark A.; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2015-05-01

    In this paper, the principle, simulation, and experiment results of tomographic imaging of a cylindrical conducting object using random noise waveforms are presented. Theoretical analysis of scattering and the image reconstruction technique are developed based on physical optics approximation and Fourier diffraction tomography, respectively. The bistatic radar system is designed to transmit band-limited ultra-wideband (UWB) random noise waveforms at a fixed position, and a linear scanner allows a single receiving antenna to move along a horizontal axis for backward scattering measurement in the frequency range from 3-5 GHz. The reconstructed tomographic image of the rotating cylindrical conducting object based on experimental results are seen to be in good agreement with the simulation results, which demonstrates the capability of UWB noise radar for complete two-dimensional tomographic image reconstruction of a cylindrical conducting object.

  1. Implementation Status of a Ultra-Wideband Receiver Package for the next-generation Very Large Array

    Science.gov (United States)

    Lazio, T. Joseph W.; Velazco, Jose; Soriano, Melissa; Hoppe, Daniel; Russell, Damon; D'Addario, Larry; Long, Ezra; Bowen, James; Samoska, Lorene; Janzen, Andrew

    2017-01-01

    The next-generation Very Large Array (ngVLA) is a concept for a radio astronomical interferometric array operating in the frequency range 1.2 GHz to 116 GHz and designed to provide substantial improvements in sensitivity, angular resolution, and frequency coverage above the current Very Large Array (VLA). As notional design goals, it would have a continuous frequency coverage of 1.2 GHz to 48 GHz and be 10 times more sensitive than the VLA (and 25 times more sensitive than a 34 m diameter antenna of the Deep Space Network [DSN]). One of the key goals for the ngVLA is to reduce the operating costs without sacrificing performance. We are designing an ultra-wideband receiver package designed to operate across the 8 to 48 GHz frequency range, which can be contrasted to the current VLA, which covers this frequency range with five receiver packages. Reducing the number of receiving systems required to cover the full frequency range would reduce operating costs, and the objective of this work is to develop a prototype integrated feed-receiver package with a sensitivity performance comparable to current narrower band systems on radio telescopes and the DSN, but with a design that meets the requirement of low long-term operational costs. The ultra-wideband receiver package consists of a feed horn, low-noise amplifier (LNA), and down-converters to analog intermediate frequencies. Key features of this design are a quad-ridge feed horn with dielectric loading and a cryogenic receiver with a noise temperature of no more than 30 K at the low end of the band. We will report on the status of this receiver package development including the feed design and LNA implementation. We will present simulation studies of the feed horn including the insertion of dielectric components for improved illumination efficiencies across the band of interest. In addition, we will show experimental results of low-noise 35nm InP HEMT amplifier testing performed across the 8-50 GHz frequency range

  2. Detection of buried objects using ultra-wideband radar: newly launched mine detection project in South Korea

    Science.gov (United States)

    Kam, Kyungryul; Kim, Kangwook

    2008-04-01

    Korea is one of the heavily mined countries in the world. The demand for mine detection and clearance techniques has always been high in South Korea. In support of this, a new project on ground penetrating radar (GPR) for landmine detection has been launched in South Korea. The GPR under development is an ultra wideband sensor system that requires high-resolution imaging of buried targets and database construction based on target signals in various ground conditions. For initial experiments, a simple GPR has been built using a resistive vee dipole antenna and a vector network analyzer. The GPR is scanned over a sand tank with an area of 2.5m × 2.5m and a depth of 1.5m, which is used for target burial. During the first stage of the project, the data obtained by scanning the GPR antenna over a target are processed to evaluate various radar signal waveforms, performance of various antennas, and other system configurations. Based on the evaluation, an advanced GPR system will be built and used to construct the database during the second stage of the project. A description for motivation for the GPR project, overview of the GPR project, experiment setup, and initial experiment results are presented in this paper.

  3. Impulse radio ultra wideband wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry.

    Science.gov (United States)

    Ebrazeh, Ali; Bozorgzadeh, Bardia; Mohseni, Pedram

    2015-01-01

    This paper demonstrates the feasibility of utilizing impulse radio ultra wideband (IR-UWB) signaling technique for reliable, wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) to address the problem of elevated data rates in high-channel-count neurochemical monitoring. Utilizing an FSCV-sensing chip fabricated in AMS 0.35μm 2P/4M CMOS, a 3-5-GHz, IR-UWB transceiver (TRX) chip fabricated in TSMC 90nm 1P/9M RF CMOS, and two off-chip, miniature, UWB antennae, wireless transfer of pseudo-random binary sequence (PRBS) data at 50Mbps over a distance of <;1m is first shown with bit-error rates (BER) <; 10(-3). Further, IR-UWB wireless transmission of dopamine concentration levels prerecorded with FSCV at a CFM during flow injection analysis (FIA) is also demonstrated with transmitter (TX) power dissipation of only ~4.4μW from 1.2V, representing two orders of magnitude reduction in TX power consumption compared to that of a conventional frequency-shift-keyed (FSK) link operating at ~433MHz.

  4. Iterative Frequency-Domain Channel Estimation and Equalization for Ultra-Wideband Systems with Short Cyclic Prefix

    Directory of Open Access Journals (Sweden)

    Salim Bahçeci

    2010-01-01

    Full Text Available In impulse radio ultra-wideband (IR-UWB systems where the channel lengths are on the order of a few hundred taps, conventional use of frequency-domain (FD processing for channel estimation and equalization may not be feasible because the need to add a cyclic prefix (CP to each block causes a significant reduction in the spectral efficiency. On the other hand, using no or short CP causes the interblock interference (IBI and thus degradation in the receiver performance. Therefore, in order to utilize FD receiver processing UWB systems without a significant loss in the spectral efficiency and the performance, IBI cancellation mechanisms are needed in both the channel estimation and equalization operations. For this reason, in this paper, we consider the joint FD channel estimation and equalization for IR-UWB systems with short cyclic prefix (CP and propose a novel iterative receiver employing soft IBI estimation and cancellation within both its FD channel estimator and FD equalizer components. We show by simulation results that the proposed FD receiver attains performances close to that of the full CP case in both line-of-sight (LOS and non-line-of-sight (NLOS UWB channels after only a few iterations.

  5. Performance analysis of a rate adaptive multi-band ultra-wideband system based on quadrature fractal modulation scheme

    Institute of Scientific and Technical Information of China (English)

    LI Yu-hong; ZHOU Zheng

    2005-01-01

    A rate adaptive multi-band ultra-wideband (UWB) system based on the quadrature fractal modulation (QFM)scheme was proposed. Exploring the use of homogeneous signals as modulating waveforms in UWB system, the signal within each 528MHz sub-band was divided into 8 different frequency bandwidths using wavelets transform and these data sequences to be transmitted were embedded into homogeneous waveforms. It is found that the use of homogeneous signals in such UWB system is quite feasible, leadings to a novel multi-rate diversity strategy. Within each 528MHz sub-band, the UWB-QFM system can provide much higher data rates than that of the UWB orthogonal frequency division multiplexing (OFDM) system. Simulation results also show that the bit error rate (BER) performance of the UWB-QFM system achieves a greatly improvement over existing UWB-OFDM system. Due to the fractal properties of the homogeneous signals, these data sequences to be transmitted can be recovered using arbitrarily short receiver signal.

  6. Through-the-Wall Localization of a Moving Target by Two Independent Ultra Wideband (UWB Radar Systems

    Directory of Open Access Journals (Sweden)

    Jana Rovňáková

    2013-09-01

    Full Text Available In the case of through-the-wall localization of moving targets by ultra wideband (UWB radars, there are applications in which handheld sensors equipped only with one transmitting and two receiving antennas are applied. Sometimes, the radar using such a small antenna array is not able to localize the target with the required accuracy. With a view to improve through-the-wall target localization, cooperative positioning based on a fusion of data retrieved from two independent radar systems can be used. In this paper, the novel method of the cooperative localization referred to as joining intersections of the ellipses is introduced. This method is based on a geometrical interpretation of target localization where the target position is estimated using a properly created cluster of the ellipse intersections representing potential positions of the target. The performance of the proposed method is compared with the direct calculation method and two alternative methods of cooperative localization using data obtained by measurements with the M-sequence UWB radars. The direct calculation method is applied for the target localization by particular radar systems. As alternative methods of cooperative localization, the arithmetic average of the target coordinates estimated by two single independent UWB radars and the Taylor series method is considered.

  7. Integrated reconfigurable multiple-input–multiple-output antenna system with an ultra-wideband sensing antenna for cognitive radio platforms

    KAUST Repository

    Hussain, Rifaqat

    2015-06-18

    © The Institution of Engineering and Technology 2015. A compact, novel multi-mode, multi-band frequency reconfigurable multiple-input-multiple-output (MIMO) antenna system, integrated with ultra-wideband (UWB) sensing antenna, is presented. The developed model can be used as a complete antenna platform for cognitive radio applications. The antenna system is developed on a single substrate area of dimensions 65 × 120 mm2. The proposed sensing antenna is used to cover a wide range of frequency bands from 710 to 3600 MHz. The frequency reconfigurable dual-element MIMO antenna is integrated with P-type, intrinsic, N-type (PIN) diodes for frequency agility. Different modes of selection are used for the MIMO antenna system reconfigurability to support different wireless system standards. The proposed MIMO antenna configuration is used to cover various frequency bands from 755 to 3450 MHz. The complete system comprising the multi-band reconfigurable MIMO antennas and UWB sensing antenna for cognitive radio applications is proposed with a compact form factor.

  8. Design guidelines, scan behavior and characteristic mode analysis for a class of ultra-wideband microstrip patch antennas

    Science.gov (United States)

    Elsewe, Mohamed Mahmoud

    Ultra-wideband (UWB), low-profile microstrip patch antennas and phased arrays have their niche in many wireless communication and medical applications. In recent years, the U-slot patch antenna established itself as a versatile antenna that can be fine-tuned for ultra-wideband operations. The L-shaped probe feeding method has additionally led to improved impedance bandwidth for the U-slot patch antenna. The L-probe's simple structure together with its low production cost makes it an attractive feeding method for the U-slot microstrip patch antenna. In phased arrays, scan blindness due to surface wave excitations can reduce the scan bandwidth range. By reducing the mutual coupling between array elements, the scan blindness effects will be reduced. Also, by reducing the sidelobe levels and minimizing the effect of grating lobes in phased arrays, the array's scan performance and power efficiency can be improved. In this dissertation, (1) a parametric study is performed on epsilon r = 2.2 and 4.5 substrates for the design of ideal L-probe feed dimensions with optimum impedance bandwidth. Results show that first-pass optimum impedance bandwidth of over 50% is achieved using the ideal L-probe feed dimensions. (2) The mutual coupling between a 2-element UWB microstrip array using different patch orientations and U-slot topologies is examined for epsilonr = 2.2 and 4.5 substrates to reduce the effect of scan blindness. Results, for epsilonr = 2.2 substrate, indicate that a diamond patch orientation with opposite U-slot topology presents the least coupling between the array elements. For epsilonr = 4.5 substrate, the E-plane patch orientation with parallel U-slot topology has the least coupling. (3) The scan behavior of 5x5 planar phased arrays using different patch orientations and U-slot topologies is examined for epsilonr = 2.2 substrate. Results indicate that blind spots are less prevalent in the diamond patch orientation and more prevalent in the E-plane patch

  9. Penetration and propagation into biological matter and biological effects of high-power ultra-wideband pulses: a review.

    Science.gov (United States)

    Schunck, Thérèse; Bieth, François; Pinguet, Sylvain; Delmote, Philippe

    2016-01-01

    Systems emitting ultra-wideband high power microwave (HP/UWB) pulses are developed for military and civilian applications. HP/UWB pulses typically have durations on the order of nanoseconds, rise times of picoseconds and amplitudes around 100 kV m(-1). This article reviews current research on biological effects from HP/UWB exposure. The different references were classified according to endpoints (cardiovascular system, central nervous system, behavior, genotoxicity, teratology …). The article also reviews the aspects of mechanisms of interactions and tissue damage as well as the numerical work that has been done for studying HP/UWB pulse propagation and pulse energy deposition inside biological tissues. The mechanisms proposed are the molecular conformation change, the modification of chemical reaction rates, membrane excitation and breakdown and direct electrical forces on cells or cell constituents, and the energy deposition. As regards the penetration of biological matter and the deposited energy, mainly computations were published. They have shown that the EM field inside the biological matter is strongly modified compared to the incident EM field and that the energy absorption for HP/UWB pulses occurs in the same way as for continuous waves. However, the energy carried by a HP/UWB pulse is very low and the deposited energy is low. The number of published studies dealing with the biological effects is small and only a few pointed out slight effects. It should be further noted that the animal populations used in the studies were not always large, the statistical analyses not always relevant and the teams involved in this research rather limited in number.

  10. 4 Gbps impulse radio (IR) ultra-wideband (UWB) transmission over 100 meters multi mode fiber with 4 meters wireless transmission.

    Science.gov (United States)

    Jensen, Jesper Bevensee; Rodes, Roberto; Caballero, Antonio; Yu, Xianbin; Gibbon, Timothy Braidwood; Monroy, Idelfonso Tafur

    2009-09-14

    We present experimental demonstrations of in-building impulse radio (IR) ultra-wideband (UWB) link consisting of 100 m multi mode fiber (MMF) and 4 m wireless transmission at a record 4 Gbps, and a record 8 m wireless transmission at 2.5 Gbps. A directly modulated vertical cavity surface emitting laser (VCSEL) was used for the generation of the optical signal. 8 m at 2.5 Gbps corresponds to a bit rate--distance product of 20; the highest yet reported for wireless IR-UWB transmission.

  11. Ultra-wideband ladder filters using zero-th shear mode plate wave in ultrathin LiNbO3 plate with apodized interdigital transducers

    Science.gov (United States)

    Kadota, Michio; Tanaka, Shuji

    2016-07-01

    There are two kinds of plate waves propagating in a thin plate, Lamb and shear horizontal (SH) waves. The former has a velocity higher than 15,000 m/s when the plate is very thin. On the contrary, 0th SH (SH0) mode plate wave in an ultrathin LiNbO3 plate has an electro-mechanical coupling factor larger than 50%. Authors fabricated an ultra-wideband T-type ladder filter with a relative bandwidth (BW) of 41% using the SH0 mode plate wave. Although the BW of the filter fully covers the digital TV band in Japan, it does not have sufficient margin at the lower and higher end of BW. Besides, periodic small ripples due to transverse mode in pass-band of the filter were observed. In this study π-type ladder filters were fabricated by changing the pitch ratio of interdigital transducer (IDT) of parallel and series arm resonators (PR(IDT)) to control the BW, and by apodizing IDTs to improve the periodic small ripples due to transverse mode. Ultra-wideband filters without periodic small transverse mode with ultrawide bandwidth from 41 to 49% were fabricated. The BWs fully cover ultrawide digital television bands in Japan and U.S.A. These filters with an ultrawide BW and a steep characteristic show the possibility to be applied to a reported cognitive radio system and other communication systems requiring an ultrawide BW.

  12. All-optical ultra-wideband doublet signal source based on the cross-gain modulation in a semiconductor optical amplifier

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zan-shan; LI Pei-li; ZHENG Jia-jin; PAN Ting-ting; HUANG Shi-jie; LUO You-hong

    2012-01-01

    We propose a novel scheme to generate the ultra-wideband (UWB) doublet signal pulse based on the cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA).In the scheme,only an optical source and an SOA are needed.As there is only one wavelength included in the output doublet signal pulse,no time difference between the upper and down pulses is introduced during the transmission process.By using the software of Optisystem 7.0,the impacts of the optical power,the SOA current,the wavelength and the input signal pulse width on the generated doublet pulse are simulated and tudied numerically.The results show that when the pulse width of the input signal pulse is larger,the output signal pulse is better,and is insensitive to the change of wavelength.In addition,the ultra-wideband positive and negative monocycles can be generated by choosing suitable optical source power and SOA current.

  13. A Bayesian Retrieval of Greenland Ice Sheet Internal Temperature from Ultra-wideband Software-defined Microwave Radiometer (UWBRAD) Measurements

    Science.gov (United States)

    Duan, Y.; Durand, M. T.; Jezek, K. C.; Yardim, C.; Bringer, A.; Aksoy, M.; Johnson, J.

    2015-12-01

    The ultra-wideband software-defined microwave radiometer (UWBRAD) is designed to provide ice sheet internal temperature product via measuring low frequency microwave emission. Twelve channels ranging from 0.5 to 2.0 GHz are covered by the instrument. A Bayesian framework was designed to retrieve the ice sheet internal temperature from UWBRAD brightness temperature (Tb) measurements for the Greenland air-borne demonstration scheduled for summer 2016. Several parameters would affect the ice sheet physical temperature. And the effective surface temperature, geothermal heat flux and the variance of upper layer ice density were treated as unknown random variables within the retrieval framework. Synthetic brightness temperature were calculated by the snow radiation transfer models as a function of ice temperature, ice density, and an estimate of snow grain size in the upper layers. A incoherent model-the Microwave Emission Model of Layered Snowpacks (MEMLS) and a coherent model were used respectively to estimate the influence of coherent effect. The inputs of the radiation transfer model were generated from a 1-D heat-flow equation developed by Robin and a exponential fit of ice density variation from Borehole measurement. The simulated Tb was corrupted with white noise and served as UWBRAD observation in retrieval. A look-up table was developed between the parameters and the corresponding Tb. In the Bayesian retrieval process, each parameter was defined with its possible range and set to be uniformly distributed. The Markov Chain Monte Carlo (MCMC) approach was applied to make the unknown parameters randomly walk in the parameter space. Experiment results were examined for science goals on three levels: estimation of the 10-m firn temperature, the average temperature integrated with depth, and the entire temperature profile. The 10-m temperature was estimated to within 0.77 K, with a bias of 0.6 K, across the 47 locations on the ice sheet; the 10-m "synthetic true

  14. Ultra-wideband printed antennas for communication applications%用于通信的超宽带印刷天线

    Institute of Scientific and Technical Information of China (English)

    钟顺时; 梁仙灵; 姚风薇; 汪伟; 白晓峰

    2006-01-01

    A new type of ultra-wideband (UWB) printed monopole antennas is presented, which is composed of a circular or annular patch and a trapeziform ground plane with a tapered CPW feeder in the middle. Both simulated and experimental results are presented,showing good agreement and therefore verifying validity of the design. The proposed antenna with a circular monopole patch achieves an 11.6: 1 measured ratio bandwidth of VSWR ≤ 2 ( from 0.79 GHz to 9.16 GHz), while that with an annular patch obtains a measured ratio impedance bandwidth of 10.6:1 (from 0.87 GHz to 9.47 GHz). In addition, these designs exhibit nearly omnidirectional radiation patterns with simple compact structures, which are attractive in communications and others UWB applications.

  15. 改进的圆形单极子超宽带天线%Improved circular monopole ultra-wideband antenna

    Institute of Scientific and Technical Information of China (English)

    郁剑

    2015-01-01

    An improved circular monopole ultra-wideband antenna was proposed. This antenna was designed by cutting the circular patch edge and increasing circle. The thickness of the substrate was 1.6 mm and the substrate material was FR4 with a relative permittivity of 4.4. The antenna was optimized by changing the size of the circular patch. The simulated results demonstrate the bandwidth (S11≤–10 dB) of the antenna is from 3.03 GHz to 11.55 GHz, the relative bandwidth comes to 116.9%, and the size is 30 mm×31 mm. The size of the antenna is decreased and this antenna can be applied to ultra wideband communication system.%为了有效地对圆形单极子超宽带天线进行小型化,在圆形贴片上进行切边和加圆处理,设计了一款尺寸为30 mm×31 mm的改进型圆形单极子天线。该天线印刷在相对介电常数为4.4、厚度为1.6 mm的FR4介质板上,通过改变切边圆和所加圆的尺寸对天线进行优化。实验结果表明,该天线在S11≤–10 dB的工作带宽为3.03~11.55 GHz,相对带宽为116.9%。该天线减小了传统圆形单极子天线的尺寸,可应用于超宽带通信系统中。

  16. 小型化超宽带印刷单极子天线%Miniaturized Ultra-wideband Printed Monopole Antenna

    Institute of Scientific and Technical Information of China (English)

    靳朋远; 温浩

    2012-01-01

    This paper presents a miniaturized ultra-wideband printed monopole antenna,impedance bandwidth of 3.17 -50GHz.The antenna adopts a circular monopole radiation structure,using coplanar waveguide feeding mode,the antenna size is 30 ×32 × 1.6mm,by appropriate adjustment of the floor size and circular radiation unit radius,can make the antenna has very good impedance matching.Com- pared with previous antenna,widening the bandwidth,smaller size,the antenna has good radiation per- formance,achieving miniaturization requirements,can provide future ultra wideband communication application to provide a good choice.%该文提出一种小型化超宽带印刷单极子天线,阻抗带宽为3.17~50GHz。该天线采用圆彤单板子为辐射结构,利用共而波导馈电方式.天线的尺寸为30×32×1.6mm,通过适当地调整板尺寸和阋形辐射单元的半径,可以使天线得到很好的阻抗匹配。与以往的天线相比,带宽更宽,尺寸更小,天线具有良好的辐射性能,达到了小型化的婪求.可为将来的超宽带通信应用提供良好的选择。

  17. 四种超宽带扩频方案的电磁兼容性能研究%Research on the Electromagnetic Compatibility of Four Ultra-wideband Spread Spectrum Schemes

    Institute of Scientific and Technical Information of China (English)

    赵亮; 金梁; 刘双平; 黄开枝; 钟州

    2011-01-01

    As the protection distance is limited, ultra-wideband signals may still interfere another communication system even with the satisfaction of the power spectral density limit. This paper derives the common expressions of bit error rate of another communication system without spread spectrum under the interference of the four ultra-wideband spread spectrum signals which pass through AWGN channel, and the four ultra-wideband spread spectrum schemes are direct sequence spread spectrum, time-hopping spread spectrum, frequency-hopping spread spectrum and chirp spread spectrum. The derived expressions are validated by Monte Carlo simulations. Also provided here are the simulation results obtained when ultra-wideband spread spectrum signals pass through IEEE 802.15.3a CM4 channel. The conclusions can be used as important references for the electromagnetic compatibility performance evaluation and the selection of spread spectrum schemes of ultra-wideband systems.%由于保护距离有限,在满足功率谱密度限制的条件下超宽带信号仍然可能对其它通信系统产生一定的干扰.该文在直接序列扩频、跳时扩频、跳频扩频和线性调频扩频4种超宽带扩频信号通过AWGN信道时,推导了在超宽带扩频信号干扰下未扩频的其它通信系统误比特率的通用表达式,并通过蒙特卡罗仿真验证了理论推导的正确性.同时还给出了超宽带扩频信号通过IEEE802.15.3aCM4信道时的仿真结果.这些结论为超宽带系统的电磁兼容性能评价和扩频方案选择提供了重要参考.

  18. MODIFIED ULTRA WIDEBAND CIRCULAR PRINTED MONOPOLE ANTENNA%改进的圆形超宽带印刷单极子天线

    Institute of Scientific and Technical Information of China (English)

    何小祥; 邓宏伟

    2008-01-01

    A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna is presented.The antenna is composed of a circular radiator and a finitely grounded plane.The antenna occupies about 16.62 GHz absolute bandwidth and 142.7%relative bandwidth covering from 3.38 GHz to 20 GHe with voltage standing wave ratio (VSWR) below two.A quasi-omnidirectional and quasi-symmetrical radiation pattern in H plane is obtained in the whole bandwidth.The high performance of the antenna is validated with measured and simulated results given.The antenna can be applied for the system design of UWB wireless communication.%给出一种新型紧凑的带陷超宽带印刷单极子天线,天线由圆形辐射贴片和有限接地平面组成.天线输入端驻波比小于2的带宽覆盖3.38-20 GHz频率范围,具有16.62GHz的绝对带宽和142.7%的相对带宽.在整个频带范围内,方向图H面近似全向且对称.仿真与测量结果验证了该天线的优越性,该天线可以方便用于超宽带无线通信领域.

  19. Channel Analysis and Estimation and Compensation of Doppler Shift in Underwater Acoustic Communication and Mitigation of IFI, ISI in Ultra-wideband Radio

    Science.gov (United States)

    Ahmed, Sadia

    Water occupies three fourth of earth's surface. The remaining one fourth is land. Although human habitats reside on land, there is no denying of the vital connection between land and water. The future sustainability of human species on this planet depends on wise utilization of all available resources, including that provided by the vast water world. Therefore, it is imperative to explore, understand, and define this massive, varying, and in many areas, unexplored water domain. The water domain exploration and data collection can be conducted using manned or unmanned vehicles, as allowed by the water environment. This dissertation addresses three of the key difficulties that occur during underwater acoustic communication among manned and/or unmanned vehicles and proposes feasible solutions to resolve those difficulties. The focus and the contributions of this research involve the following perspectives: 1) Representation of Underwater Acoustic Communication (UAC) Channels: Providing a comprehensive classification and representation of the underwater acoustic communication channel based on the channel environment. 2) Estimation and Compensation of Doppler Shift: Providing compensation algorithm to mitigate varying Doppler shift effect over subcarriers in UAC Orthogonal Frequency Division Multiplexing (OFDM) systems. 3) Mitigation of Inter-symbol Interference (ISI): Providing feasible solution to long delay spread causing ISI in Ultra-wideband channels.

  20. A Reconfigurable Triple-Notch-Band Antenna Integrated with Defected Microstrip Structure Band-Stop Filter for Ultra-Wideband Cognitive Radio Applications

    Directory of Open Access Journals (Sweden)

    Yingsong Li

    2013-01-01

    Full Text Available A printed reconfigurable ultra-wideband (UWB monopole antenna with triple narrow band-notched characteristics is proposed for cognitive radio applications in this paper. The triple narrow band-notched frequencies are obtained using a defected microstrip structure (DMS band stop filter (BSF embedded in the microstrip feed line and an inverted π-shaped slot etched in the rectangular radiation patch, respectively. Reconfigurable characteristics of the proposed cognitive radio antenna (CRA are achieved by means of four ideal switches integrated on the DMS-BSF and the inverted π-shaped slot. The proposed UWB CRA can work at eight modes by controlling switches ON and OFF. Moreover, impedance bandwidth, design procedures, and radiation patterns are presented for analysis and explanation of this antenna. The designed antenna operates over the frequency band between 3.1 GHz and 14 GHz (bandwidth of 127.5%, with three notched bands from 4.2 GHz to 6.2 GHz (38.5%, 6.6 GHz to 7.0 GHz (6%, and 12.2 GHz to 14 GHz (13.7%. The antenna is successfully simulated, fabricated, and measured. The results show that it has wide impedance bandwidth, multimodes characteristics, stable gain, and omnidirectional radiation patterns.

  1. Compact ultra-wideband microstrip bandpass filter design%一个紧凑型超宽带微带带通滤波器

    Institute of Scientific and Technical Information of China (English)

    李玉龙; 宋树祥; 岑明灿; 凡东东

    2016-01-01

    A compact ultra-wideband microstrip bandpass filter was designed and fabricated, which was composed of a microstrip low-pass filter and two pair of minor lines that included a quarter wavelength SIR resonator and a quarter wavelength short end resonator. The filter was simulated by using ADS software, and was fabricated. Results show that the filter’s relative bandwidth reaches 112%, the stopband bandwidth is more than 4 GHz, the insertion loss is less than 1 dB and the return loss is more than 10 dB in passband range, and the stopband return loss is greater than 20 dB. The filter size is 14.22 mm × 9.65 mm.%设计制作了一种紧凑型超宽带微带带通滤波器。该滤波器采用两对由1/4波长型SIR谐振器和1/4波长终端短路谐振器构成的枝节线对与微带低通滤波器相联而成。在 ADS 软件上对该滤波器进行仿真验证,然后制作实物。结果表明,该滤波器相对带宽达到112%,阻带带宽超过4 GHz,通带范围内插入损耗小于1 dB,回波损耗大于10 dB,阻带范围回波损耗大于20 dB;滤波器尺寸为14.22 mm ×9.65 mm。

  2. Design and performance of an ultra-wideband stepped-frequency radar with precise frequency control for landmine and IED detection

    Science.gov (United States)

    Phelan, Brian R.; Sherbondy, Kelly D.; Ranney, Kenneth I.; Narayanan, Ram M.

    2014-05-01

    The Army Research Laboratory (ARL) has developed an impulse-based vehicle-mounted forward-looking ultra- wideband (UWB) radar for imaging buried landmines and improvised explosive devices (IEDs). However, there is no control of the radiated spectrum in this system. As part of ARL's Partnerships in Research Transition (PIRT) program, the above deficiency is addressed by the design of a Stepped-Frequency Radar (SFR) which allows for precise control over the radiated spectrum, while still maintaining an effective ultra-wide bandwidth. The SFR utilizes a frequency synthesizer which can be configured to excise prohibited and interfering frequency bands and also implement frequency-hopping capabilities. The SFR is designed to be a forward-looking ground- penetrating (FLGPR) Radar utilizing a uniform linear array of sixteen (16) Vivaldi notch receive antennas and two (2) Quad-ridge horn transmit antennas. While a preliminary SFR consisting of four (4) receive channels has been designed, this paper describes major improvements to the system, and an analysis of expected system performance. The 4-channel system will be used to validate the SFR design which will eventually be augmented in to the full 16-channel system. The SFR has an operating frequency band which ranges from 300 - 2000 MHz, and a minimum frequency step-size of 1 MHz. The radar system is capable of illuminating range swaths that have maximum extents of 30 to 150 meters (programmable). The transmitter has the ability to produce approximately -2 dBm/MHz average power over the entire operating frequency range. The SFR will be used to determine the practicality of detecting and classifying buried and concealed landmines and IEDs from safe stand-off distances.

  3. Obstacle avoidance and concealed target detection using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) forward imaging radar

    Science.gov (United States)

    Nguyen, Lam; Wong, David; Ressler, Marc; Koenig, Francois; Stanton, Brian; Smith, Gregory; Sichina, Jeffrey; Kappra, Karl

    2007-04-01

    The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR) for forward imaging to support the Army's vision of an autonomous navigation system for robotic ground vehicles. These unmanned vehicles, equipped with an array of imaging sensors, will be tasked to help detect man-made obstacles such as concealed targets, enemy minefields, and booby traps, as well as other natural obstacles such as ditches, and bodies of water. The ability of UWB radar technology to help detect concealed objects has been documented in the past and could provide an important obstacle avoidance capability for autonomous navigation systems, which would improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U. S. forces on the battlefield. One of the primary features of the radar is the ability to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique where several relatively slow and inexpensive analog-to-digital (A/D) converters are used to sample the wide bandwidth of the radar signals. We conducted an experiment this winter at Aberdeen Proving Ground (APG) to support the phenomenological studies of the backscatter from positive and negative obstacles for autonomous robotic vehicle navigation, as well as the detection of concealed targets of interest to the Army. In this paper, we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the forward imaging techniques used in the experiment. Finally, we will present imagery of man-made obstacles such as barriers, concertina wires, and mines.

  4. An Ultra-Wideband, Microwave Radar for Measuring Snow Thickness on Sea Ice and Mapping Near-Surface Internal Layers in Polar Firn

    Science.gov (United States)

    Panzer, Ben; Gomez-Garcia, Daniel; Leuschen, Carl; Paden, John; Rodriguez-Morales, Fernando; Patel, Azsa; Markus, Thorsten; Holt, Benjamin; Gogineni, Prasad

    2013-01-01

    Sea ice is generally covered with snow, which can vary in thickness from a few centimeters to >1 m. Snow cover acts as a thermal insulator modulating the heat exchange between the ocean and the atmosphere, and it impacts sea-ice growth rates and overall thickness, a key indicator of climate change in polar regions. Snow depth is required to estimate sea-ice thickness using freeboard measurements made with satellite altimeters. The snow cover also acts as a mechanical load that depresses ice freeboard (snow and ice above sea level). Freeboard depression can result in flooding of the snow/ice interface and the formation of a thick slush layer, particularly in the Antarctic sea-ice cover. The Center for Remote Sensing of Ice Sheets (CReSIS) has developed an ultra-wideband, microwave radar capable of operation on long-endurance aircraft to characterize the thickness of snow over sea ice. The low-power, 100mW signal is swept from 2 to 8GHz allowing the air/snow and snow/ ice interfaces to be mapped with 5 c range resolution in snow; this is an improvement over the original system that worked from 2 to 6.5 GHz. From 2009 to 2012, CReSIS successfully operated the radar on the NASA P-3B and DC-8 aircraft to collect data on snow-covered sea ice in the Arctic and Antarctic for NASA Operation IceBridge. The radar was found capable of snow depth retrievals ranging from 10cm to >1 m. We also demonstrated that this radar can be used to map near-surface internal layers in polar firn with fine range resolution. Here we describe the instrument design, characteristics and performance of the radar.

  5. Ultra-wideband electronics, design methods, algorithms, and systems for dielectric spectroscopy of isolated B16 tumor cells in liquid medium

    Science.gov (United States)

    Maxwell, Erick N.

    Quantifying and characterizing isolated tumor cells (ITCs) is of interest in surgical pathology and cytology for its potential to provide data for cancer staging, classification, and treatment. Although the independent prognostic significance of circulating ITCs has not been proven, their presence is gaining clinical relevance as an indicator. However, researchers have not established an optimal method for detecting ITCs. Consequently, this Ph.D. dissertation is concerned with the development and evaluation of dielectric spectroscopy as a low-cost method for cell characterization and quantification. In support of this goal, ultra-wideband (UWB), microwave pulse generator circuits, coaxial transmission line fixtures, permittivity extraction algorithms, and dielectric spectroscopy measurement systems were developed for evaluating the capacity to quantify B16-F10 tumor cells in suspension. First, this research addressed challenges in developing tunable UWB circuits for pulse generation. In time-domain dielectric spectroscopy, a tunable UWB pulse generator facilitates exploration of microscopic dielectric mechanisms, which contribute to dispersion characteristics. Conventional approaches to tunable pulse generator design have resulted in complex circuit topologies and unsymmetrical waveform morphologies. In this research, a new design approach for low-complexity, tunable, sub-nanosecond and UWB pulse generator was developed. This approach was applied to the development of a novel generator that produces symmetrical waveforms (patent pending 60/597,746). Next, this research addressed problems with transmission-reflection (T/R) measurement of cell suspensions. In T/R measurement, coaxial transmission line fixtures have historically required an elaborate sample holder for containing liquids, resulting in high cost and complexity. Furthermore, the algorithms used to extract T/R dielectric properties have suffered from myriad problems including local minima and

  6. TSGC and JSC Alignment

    Science.gov (United States)

    Sanchez, Humberto

    2013-01-01

    NASA and the SGCs are, by design, intended to work closely together and have synergistic Vision, Mission, and Goals. The TSGC affiliates and JSC have been working together, but not always in a concise, coordinated, nor strategic manner. Today we have a couple of simple ideas to present about how TSGC and JSC have started to work together in a more concise, coordinated, and strategic manner, and how JSC and non-TSG Jurisdiction members have started to collaborate: Idea I: TSGC and JSC Technical Alignment Idea II: Concept of Clusters.

  7. 基于并联SOA的全光广播式超宽带脉冲形状调制技术%Research on all-optical broadcasting ultra-wideband pulse shape modulation based on multiple semiconductor optical amplifiers

    Institute of Scientific and Technical Information of China (English)

    马晓璐; 李培丽; 郑加金; 张一; 朱天阳

    2013-01-01

    基于半导体光放大器(SOA)中交叉增益调制(XGM)效应,采用SOA的并联结构,提出了一种全光产生广播式超宽带(UWB)脉冲形状调制(PSM)信号的方案.该方案同时产生三路超宽带PSM信号,具有多用户传输数据的能力,可为多址通信作理论基础;采用相向的工作方式可以改善输出信号的消光比.利用OptiSystem7.0软件对方案进行仿真,分析了输入信号脉冲宽度、输入光功率和波长对产生的超宽带PSM信号的影响,对信号的传输特性进行了研究.结果表明,本文方案对输入信号脉冲宽度和输入光波长具有良好的容忍度,并且给出了输入光功率的优化范围.%An all-optical broadcasting ultra-wideband (UWB) pulse shape modulation (PSM) technology based on the cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA) has been demonstrated.In this novel scheme,two wideband traveling wave SOAs are used,and the structure of the parallel SOAs is adopted to generate the PSM signals.and three kinds of ultra-wideband PSM signals are generated at the smae time.As a consequence,this new scheme has the ability to transmit data among multiple users,and can be used as a theoretical basis of multiple accuess communication.As the opposite working way is used.the scheme has an advantage in improving the extinction ratio (ER) of the output three ultra-wideband PSM signals.By using the software of OptiSystem7.0,the impacts of the input signal pulse width,the optical power and the wavelength of the laser on the generated three kinds of ultrawideband PSM signal are numberically simulated and studied.In addition,the transmission characteristics of the generated PSM signal are discussed.The results show that the PSM signal has a good toleration to the pulse width,and the optimized ranges of other parameters are presented.

  8. 基于超宽带能量检测方案的数字脉冲间隔调制%Energy-detection based ultra-wideband communication using digital pulse interval modulation

    Institute of Scientific and Technical Information of China (English)

    晋本周; 张盛; 程永生; 林孝康

    2011-01-01

    The digital pulse interval modulation (DPIM) is indtroduced into energy-detection based ultra-wideband (UWB) communication systems and the performance of DPIM is studied. The modulation scheme suitable for impulse radio UWB channel is presented. DPIM transmission capacity based on the definition is analyzed and is compared with on-off keying (OOK) and pulse position modulation (PPM). Expressions of slot error probability and packet error probability are derived for DPIM. Numerical results of different modulations in one of IEEE 802. 15. 3a models show that, for certain modulation orders (e. G. , 4-DPIM vs 2-PPM), DPIM is superior to PPM in both error performance and transmission capacity. Furthermore, compared with (X)K, DPIM, with a high modulation order, achieves a better error performance at the cost of certain transmission capacity.%将数字脉冲间隔调制(digital pulse interval modulation,DPIM)引入到基于能量检测方案的超宽带(ultra-wideband,UWB)通信系统中,详细研究了DPIM的性能.给出了适合于脉冲UWB信道的DPIM方案,定义了该调制方式的传输容量并与开关键控( on-off keying,OOK)和脉冲位置调制(pulse position modulation,PPM)做比较.推导出该调制方式的误时隙率和误包率.给出了不同调制方式在IEEE 802.15.3a信道环境下的数值结果,结果表明存在某些调制阶数(如4-DPIM对2-PPM),能够使得DPIM在传输容量和包差错性能上均优于PPM.另外与OOK相比,高阶DPIM可以在损失一些传输容量条件下取得更好的包差错性能.

  9. Application of Ultra-wideband Technology in Mine Rescue Communication Monitoring System%超宽带技术在矿井救援通信监测系统中的应用

    Institute of Scientific and Technical Information of China (English)

    张传锴; 李玉良; 刘井元

    2012-01-01

    The paper put forward a design scheme of the mine rescue communication monitoring system based on the ultra-wideband(UWB) technology,and introduced the characteristics of the UWB technology and the general structure principle of the system and the technological implementation method of each part.This system realized the interactive multimedia communication and the real-time monitoring of underground environmental parameters among the disaster area site,underground coal mine rescue base and the ground command center.%提出了一种基于超宽带(UWB)技术的矿山救援通信监测系统设计方案,介绍了超宽带(UWB)技术的特点,阐述了系统的总体结构原理和各个部分的技术实现方法。实现了救灾现场、井下救援基地、地面指挥中心三者之间交互式的多媒体通信和井下环境参数的实时监测。

  10. Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rana Pratap, E-mail: ranayadav97@gmail.com; Kumar, Sunil; Kulkarni, S. V. [Thapar University, Patiala, Punjab 147004, India and Institute for Plasma Research, Gandhinagar 382428 (India)

    2016-01-15

    Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.

  11. Miniature ultra-wideband CPW-fed monopole antenna with mushroom-shaped structure%一种小型化超宽带共面波导馈电蘑菇形单极子天线

    Institute of Scientific and Technical Information of China (English)

    王宁; 刘运林; 吕春艳; 董兴超

    2013-01-01

    提出一种简单的尺寸为23 mm×25 mm×1 mm小型化超宽带共面波导馈电单极子天线,它由梯形槽口接地板、蘑菇形辐射贴片和RF4介质板构成.详细讨论了梯形槽口结构和矩形渐变结构对阻抗特性的影响,分析了天线的辐射特性和增益特性,获得该天线的回波损耗小于-10 dB的带宽为3~13 GHz,在3~11 GHz频段内具有全向性,增益变化范围是2.2~5 dB.%A simple and compact ultra-wideband monopole antenna fed by coplanar waveguide (CPW) is presented. The overall size of the antenna is 23 mm×25 mm×1 mm, which consists of a ground plane with trapezium-shaped slot and a mush-room-shaped radiating patch printed on the same side of the substrate. By optimizing trapezoid slot and loading rectangular gradient structure, the impedance matching characteristics is analyzed and a wide impedance bandwidth from 3 GHz to more than 13 GHz with 10 dB return loss is obtained. Meanwhile, the radiation characteristics and gain characteristics of the antenna are discussed. The antenna exhibits good radiation behavior and its gain varies from 2.2 dB to 5 dB in 3~11 GHz bandwidth.

  12. LTCC宽边耦合交指型超宽带滤波器设计%Design of an Ultra-Wideband LTCC filter based on broadside-coupled interdigital structure

    Institute of Scientific and Technical Information of China (English)

    惠力; 唐高弟; 李中云

    2011-01-01

    To achieve miniaturization of Ultra-Wideband(UWB) bandpass filters, a novel interdigital filter and its design method are proposed. The filter realizes large coupling coefficient using broadsidecoupled structure, and unnecessary cross coupling is reduced by widening the width of stripline resonator. It simplifies the design method of the filter. A six-pole interdigital bandpass filter is designed using the proposed structure, which is centered at fo GHz with a fractional bandwidth of 58%, and the size of the filter is 8 mm X 11 mm. The simulation results show that the filter keeps the advantages of the traditional interdigital filter with good stopband characteristics and spurious response.%提出用交指型结构实现超宽带(UWB)带通滤波器的小型化,并给出了设计方法.该结构通过宽边耦合实现超宽带滤波器需要的较大耦合系数,并通过加宽带状线谐振器的宽度减少不必要的交叉耦合,简化了滤波器的设计.最终设计了一个中心频率为f0,相对带宽为58%的六阶交指带通滤波器,滤波器尺寸仅为8 mm×11 mm.从仿真结果看,该滤波器保持了传统交指型滤波器阻带特性好,寄生通带远的优点.

  13. Center Innovation Fund: JSC CIF (also includes JSC IRAD) Program

    Data.gov (United States)

    National Aeronautics and Space Administration — JSC provides and applies its preeminent capabilities in science and technology to develop, operate, and integrate human exploration missions.  The Center...

  14. Design of A Novel Ultra-wideband Planar Equiangular Spiral Antenna%一种新颖的超宽带平面等角螺旋天线的设计

    Institute of Scientific and Technical Information of China (English)

    罗旺

    2013-01-01

    The planar spiral antenna research methods are analyzed, and the planar equiangular spiral antenna working in 2~12 GHz novel ultra-wideband is designed. For the balanced structure and broadband characteristics of the antenna, a belt-ring stickers antenna radiating structure for the antenna radiation part is designed, so that the circular polarization axis is less than 3dB than the band, while a two-form microstrip line broadband balun combining the impedance index gradient and trapezoidal grodient is designed for the antenna feed part, and 50 W coaxial probe feed may also be adopted, so that the reflection coefficient could be less than -10dB band. The measurement results indicate that both the antenna and the balun exhibit good circular polarization and broad-band property.%  分析了平面螺旋天线的研究方法,并设计了工作于2~12 GHz 的新颖的超宽带平面等角螺旋天线,由天线的宽带特性指标和平衡结构特性,天线两臂的辐射部分设计了一种带环状贴片的天线辐射结构,使圆极化轴比带内小于3 dB,天线馈电部分设计了一种阻抗为指数渐变和梯形渐变相结合的双线形式微带线宽带巴伦,并可采用50 W 同轴探针馈电,使带内反射系数小于-10 dB。测试结果表明,馈电的微带巴伦和天线带环状的结构形式都表现出良好的宽频带和圆极化特性。

  15. 3GHz~5GHz CMOS超宽带低噪声放大器设计%Design of a 3 GHz~5 GHz CMOS ultra-wideband low noise amplifier

    Institute of Scientific and Technical Information of China (English)

    王宁章; 唐江波; 秦国宾; 卢安栋; 罗婕思

    2011-01-01

    提出了一个低噪声、高线性的超宽带低噪声放大器(UWB LNA).电路由窄带PCSNIM LNA拓扑结构和并联低Q负载结构组成,采用TSMC 0.18 μm RFCMOS工艺,并在其输入输出端引入了高阶带通滤波器.仿真结果表明,在1.8V直流电压下LNA的功耗约为10.6 mW.在3 GHz~5 GHz 的超宽带频段内,增益约为13.5 dB,输入、输出回波损耗S11、S22均小于-14 dB,噪声系数(NF)为0.875 dB~4.072 dB,三阶交调点IIP3均值为5.35 dB.%A low noise, high linearity ultra-wideband low noise amplifier(UWB LNA)is presented. The circuit is constituted by PCSNIM LNA circuit topology and parallel low-Q load structure in TSMC 0.18 μm RF CMOS technology, and the high-order band-pass filters are introduced at the input and output ports. Simulation results show that at 1.8 V supply voltage the consumption of LNA is about 10.6 mW. In the 3 GHz~5 GHz UWB frequency band, gain is about 13.5 dB, input and output return loss S11、S22 is less than -14 dB, noise figure(NF) 0.875 dB~4.072 dB, third-order intercept point ⅡP3 is the average of 5.35 dB.

  16. Real-time ultra-wideband direction finding for the conformal array antenna%共形阵列天线超宽频带波达方向实时估计

    Institute of Scientific and Technical Information of China (English)

    司伟建; 万良田; 刘鲁涛; 田作喜; 蓝晓宇

    2014-01-01

    为了解决航天飞行器系统中共形阵列天线超宽频带测向问题,提出了基于共形阵列天线的任意基线实时测向算法。该算法使用轮换比对的方法实现无模糊测向,将任意基线算法扩展到三维阵列中,结合虚拟基线方法,利用子阵分割技术和矩阵求逆的方法来获得二维方位角和俯仰角信息。最后通过仿真实验对比了基于对数周期天线的立体阵列和基于平面螺旋天线的平面阵列,验证了所提方法的有效性。结果表明:所提算法在相同频率下具有相近的解模糊概率,在相同信噪比下具有较高的测角精度。%In order to solve the problem concerning the ultra-wideband direction finding for the conformal array an-tenna on an airborne system, a real-time arbitrary baseline direction finding algorithm based on the conformal array antenna has been proposed. This algorithm provides unambiguous direction finding using the rotation comparison method. The arbitrary baseline algorithm was extended to 3D array. The 2D azimuth and pitch angles estimation were acquired through use of the sub-array divided technique, matrix inversion method and the arbitrary baseline algorithm combined with the virtual baseline method. Finally, the simulation results verify the effectiveness of the proposed method by comparing the 3D conformal array based on the log-periodic dipole antenna ( LPDA) with the 2D array based on the spiral antenna. The proposed algorithm has similar solving ambiguity probability at the same frequency and high measure angle accuracy at the same SNR.

  17. Solution of the blind zone in ultra-wideband radar based on combined pulses%利用组合脉冲解决超宽带雷达中探测盲区问题

    Institute of Scientific and Technical Information of China (English)

    张朝霞; 周俊杰; 张明江; 张东泽

    2014-01-01

    The technology of pulse compression is used in the ultra-wideband (UWB)radar system to in-crease the detection capabilities.However,the blind zone is augmented at the same time.Binary phase-coded UWB signal which is modulated by the pseudo random noise (PRN)code is used as the novel combined pulses. When the maximum detection range of the short pulses is longer than the blind zone of the long pulses,it could be used to solve the problem of the rising blind zone in the UWB pulse compression radar system.The results simulated by the Matlab show that the theoretical analysis is correct and the proposed method can greatly de-crease the radar detection blind zone.This shows feasibility and superiority of the proposed method.%为了解决脉冲压缩技术运用于超宽带(ultra-wideband,UWB)雷达系统中在增加其最远探测距离的同时也增加了探测盲区这一问题,提出一种利用长短脉冲相组合的伪随机(pseudo random noise,PRN)码调制的二相编码 UWB 信号作为雷达信号发射源,在满足短脉冲的最大探测距离大于长脉冲的最小探测盲区的条件下,解决 UWB 脉冲压缩雷达系统探测盲区的问题。Matlab 仿真结果表明了理论分析的正确性及所提出的方法可以很大程度减小雷达探测盲区,说明所提出方法的可行性与优越性。

  18. JSC Design and Procedural Standards, JSC-STD-8080

    Science.gov (United States)

    Punch, Danny T.

    2011-01-01

    This document provides design and procedural requirements appropriate for inclusion in specifications for any human spaceflight program, project, spacecraft, system, or end item. The term "spacecraft" as used in the standards includes launch vehicles, orbital vehicles, non-terrestrial surface vehicles, and modules. The standards are developed and maintained as directed by Johnson Space Center (JSC) Policy Directive JPD 8080.2, JSC Design and Procedural Standards for Human Space Flight Equipment. The Design and Procedural Standards contained in this manual represent human spacecraft design and operational knowledge applicable to a wide range of spaceflight activities. These standards are imposed on JSC human spaceflight equipment through JPD 8080.2. Designers shall comply with all design standards applicable to their design effort.

  19. Dual constellations space-time modulation

    Institute of Scientific and Technical Information of China (English)

    ZOU Li; ZHAO Yuping; WANG Bing; LIANG Qinglin; XIANG Haige

    2005-01-01

    Next generation communication systems will be expected to operate under environment with high-speed motion and increasing number of antennas where it will be difficult or even impractical to estimate the real-time channel coefficients. For this reason,the DSTM (differential space time modulation) and USTM (unitary space time modulation) approaches that do not require the channel estimation became hot topics in recent years.In this paper, we propose a general approach to designing high spectral-efficiency signaling schemes. A novel modulation, dual constellations space-time modulation (DCSTM), is derived by extending DSTM and USTM theoretically. DCSTM preserves the good features of USTM such as low error rate and the capability of being demodulated without channel estimation. At the same time, it enhances the spectral efficiency and reduces the complexity of the modulation/demodulation. It can be adapted to different data rates and thus has a wider applicable area. Simulation results verify the theoretical analysis and the design of the new modulation method.

  20. 3.1~10.6 GHz低功耗超宽带低噪声放大器%A 3.1-10.6 GHz Low Power Ultra-Wideband Low Noise Amplifier

    Institute of Scientific and Technical Information of China (English)

    赵飞义; 张万荣; 丁春宝; 陈昌麟; 胡瑞心; 卓汇涵; 江之韵; 白杨; 陈亮

    2014-01-01

    采用TSMC 0.18μm CMOS工艺库,设计并验证了一种应用于3.1~10.6 GHz频段的超宽带低噪声放大器.该放大器分为两级:采用跨导增强技术的共栅结构作为输入级,实现了输入阻抗匹配,提高了增益并降低了噪声;第二级是放大输出级,由两个共源放大管和源跟随器缓冲管构成,并采用两级电流复用配置将它们连接在一起,不但对信号进行了二次放大,降低了功耗,而且实现了输出匹配.仿真结果表明,在3.1~10.6 GHz频带范围内,放大器增益为14.8 dB,增益平坦度为±0.6 dB,噪声系数介于2.9~4.5 dB,输入和输出的回波损耗均优于-11 dB,1 dB压缩点为-20.8 dBm,在1.8V电压下,静态功耗仅为8.99 mW.%Based on the TSMC 0.18 μm CMOS process library,a 3.1-10.6 GHz low power ultra-wideband low noise amplifier was designed.The amplifier consisted of two stages.At the input stage of a common-gate structure,a kind of transconductance enhancement technique was used to achieve good input match,high gain and low noise.The second stage was amplification output.It consisted of two common source amplification transistor and source follower buffering transistor which were connected through the current reuse configuration.The signal was magnified two times,therefore the power consumption was reduced,and the output match was obtained.The simulation results showed that over the range of 3.1-10.6 GHz,the power gain was 14.8 dB,the gain flatness was ±0.6 dB,the noise figure was from 2.9 dB to 4.5 dB,the input and output match loss were both below-11 dB,the 1 dB compress point was-20.8 dBm.With the supply voltage of 1.8 V,the static power consumption was only 8.99 mW.

  1. Center Independent Research & Developments: JSC IRAD Program

    Data.gov (United States)

    National Aeronautics and Space Administration — JSC provides and applies its preeminent capabilities in science and technology to develop, operate, and integrate human exploration missions.  The center...

  2. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

    Gaididei, Yu B.; Gorria, C.; Berkemer, R.

    2013-01-01

    in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well......The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case....... This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance...

  3. Controlling traffic jams by time modulating the safety distance

    Science.gov (United States)

    Gaididei, Yu. B.; Gorria, C.; Berkemer, R.; Kawamoto, A.; Shiga, T.; Christiansen, P. L.; Sørensen, M. P.; Starke, J.

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  4. ROTATION CONSTELLATION FOR DIFFERENTIAL UNITARY SPACE-TIME MODULATION

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Cao Haiyan; Wei Gang

    2006-01-01

    A new constellation which is the multiplication of the rotation matrix and the diagonal matrix according to the number of transmitters is proposed to increase the diversity product, the key property to the performance of the differential unitary space-time modulation. Analyses and the simulation results show that the proposed constellation performs better and 2dB or more coding gain can be achieved over the traditional cyclic constellation.

  5. Design of Data Converters for Dual-carrier Orthogonal Frequency-Division Multiplexing Ultra-wideband System%适用于双载波-正交频分复用超宽带系统的数据转换器设计

    Institute of Scientific and Technical Information of China (English)

    夏杰峰; 哈钱钱; 林宇婧; 叶凡; 任俊彦

    2012-01-01

    Dual-carrier orthogonal frequency-division multiplexing (DC-OFDM) is adopted in China as the ultra-wideband (UWB) national standard. Two data converters are designed based on this UWB system standard, including a four-channel 650 MS/s 8 bit current-steering digital-to-analog converter (DAC) and a four- channel 300 MS/s 6 bit folding-and-interpolating analog-to-digital converter (ADC). Both of them are integrated on a printed circuit board (PCB). The DAC has focused on the matching of current sources and its dynamic performance is improved by reducing the voltage swing of the switch transistors. Testing result shows that one sub-DAC can achieve over 52 dB spurious-free dynamic range (SFDR) locating at 68 MHz input. The ADC adopts inter-stage pipelined switches to relax amplifiers' bandwidth, utilizes active interpolators to further mitigate the offset of the comparators and keeps the signal-to-noise-and-distortion ration (SNDR) of sub-ADC over 32 dB in the entire Nyquist band.%国家超宽带(UWB)标准采用了双载波-正交频分复用技术(DC-OFDM),此设计基于该标准的超宽带系统中用数据转换器,包括一个单片集成4通道650 MS/s 8 bit电流舵数模转换器(DAC)和一个单片集成4通道300 MS/s 6 bit折叠内插模数转换器(ADC),在印刷电路板(PCB)上实现集成.DAC设计着重考虑电流源的匹配,并且采用降摆幅电路提高动态性能,当输入频率为68 MHz时,单个子DAC无杂散动态范围(SFDR)可以达到51dB以上;ADC采用级间流水线开关降低放大器建立要求,采用有源内插进一步降低比较器失调影响,单个子ADC信噪失真比(SNDR)在整个奈奎斯特频带内都保持在32 dB以上.

  6. JSC Pharmacy Services for Remote Operations

    Science.gov (United States)

    Stoner, Paul S.; Bayuse, Tina

    2005-01-01

    The Johnson Space Center Pharmacy began operating in March of 2003. The pharmacy serves in two main capacities: to directly provide medications and services in support of the medical clinics at the Johnson Space Center, physician travel kits for NASA flight surgeon staff, and remote operations, such as the clinics in Devon Island, Star City and Moscow; and indirectly provide medications and services for the International Space Station and Space Shuttle medical kits. Process changes that occurred and continued to evolve in the advent of the installation of the new JSC Pharmacy, and the process of stocking medications for each of these aforementioned areas will be discussed. Methods: The incorporation of pharmacy involvement to provide services for remote operations and supplying medical kits was evaluated. The first step was to review the current processes and work the JSC Pharmacy into the existing system. The second step was to provide medications to these areas. Considerations for the timeline of expiring medications for shipment are reviewed with each request. The third step was the development of a process to provide accountability for the medications. Results: The JSC Pharmacy utilizes a pharmacy management system to document all medications leaving the pharmacy. Challenges inherent to providing medications to remote areas were encountered. A process has been designed to incorporate usage into the electronic medical record upon return of the information from these remote areas. This is an evolving program and several areas have been identified for further improvement.

  7. JSC Search System Usability Case Study

    Science.gov (United States)

    Meza, David; Berndt, Sarah

    2014-01-01

    The advanced nature of "search" has facilitated the movement from keyword match to the delivery of every conceivable information topic from career, commerce, entertainment, learning... the list is infinite. At NASA Johnson Space Center (JSC ) the Search interface is an important means of knowledge transfer. By indexing multiple sources between directorates and organizations, the system's potential is culture changing in that through search, knowledge of the unique accomplishments in engineering and science can be seamlessly passed between generations. This paper reports the findings of an initial survey, the first of a four part study to help determine user sentiment on the intranet, or local (JSC) enterprise search environment as well as the larger NASA enterprise. The survey is a means through which end users provide direction on the development and transfer of knowledge by way of the search experience. The ideal is to identify what is working and what needs to be improved from the users' vantage point by documenting: (1) Where users are satisfied/dissatisfied (2) Perceived value of interface components (3) Gaps which cause any disappointment in search experience. The near term goal is it to inform JSC search in order to improve users' ability to utilize existing services and infrastructure to perform tasks with a shortened life cycle. Continuing steps include an agency based focus with modified questions to accomplish a similar purpose

  8. Effects of ultra-wideband electromagnetic irradiation on the ultrastructure of rat pituitary and testis and sex hormones of rat%超宽带电磁辐射对大鼠垂体和睾丸超微结构及性激素水平的影响

    Institute of Scientific and Technical Information of China (English)

    杨明娟; 苗霞; 刘海强; 侯知佑; 曾丽华; 郭国祯

    2011-01-01

    目的 观察超宽带(ultra-wideband,UWB)电磁辐射对大鼠垂体和睾丸超微结构以及血清中性激素水平的影响。方法 将SD雄性大鼠随机分为辐照组和对照组。辐照组大鼠接受脉冲数为30万次的UWB辐照,并于辐照后6、12、24、48 h,应用透射电子显微镜观察垂体及睾丸超微结构的改变,放射免疫法检测大鼠血清中睾酮(T)、黄体生成素(LH)及促卵泡激素(FSH)水平。结果 在辐照后各时间点,大鼠垂体和睾丸均出现不同程度的损伤。在辐照后24h,垂体和睾丸损伤程度最重。垂体嗜碱细胞内质网扩张,胞浆中有空泡,出现脂滴,淋巴细胞渗出,染色质边集;睾丸组织中,精原细胞、支持细胞和间质细胞均出现染色质边集、内质网扩张,毛细血管内皮细胞线粒体肿胀、空泡化,淋巴细胞渗出。辐照组血清中T水平在辐照后24、48 h分别为(1209.7±115.7)、(1340.5±331.1)μg/L,明显低于相应对照组f分别为(2721.8±178.9)、(2820.9±321.4) μg/L],差异均有统计学意义(P<0.05),而LH和FSH均未发生明显改变。结论 UWB电磁辐射可导致大鼠垂体和睾丸超微结构发生变化,对大鼠血清中T含量有一定程度的影响,可能是UWB辐照引起大鼠生殖系统发生改变的原因之一。%Objective To observe the effects of ultra-wideband (UWB) electromagnetic irradiation on the ultrastructure of pituitary or testis and the serum sex hormones level of in rats. Methods SD male rats were divided randomly into control group and irradiation groups exposed to 3×105 pulses UWB irradiation for 6,12, 24, 48 h. After exposure, the ultrastructure changes of pituitary and testis were observed by electron microscope. Serum testosterone (T) , luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay. Results The rat pituitary and testis were injured at the different time after exposure to UWB

  9. Acoustical Direction Finding with Time-Modulated Arrays

    Science.gov (United States)

    Clark, Ben; Flint, James A.

    2016-01-01

    Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal’s direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ±1∘ within an angular range of approximately ±50∘. In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ±2.5∘ of the target signal is readily achieved inside a ±45∘ range using a single switched input stage and a simple hardware setup. PMID:27973432

  10. Acoustical Direction Finding with Time-Modulated Arrays

    Directory of Open Access Journals (Sweden)

    Ben Clark

    2016-12-01

    Full Text Available Time-Modulated Linear Arrays (TMLAs offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal’s direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ± 1 ∘ within an angular range of approximately ± 50 ∘ . In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA estimation within ± 2 . 5 ∘ of the target signal is readily achieved inside a ± 45 ∘ range using a single switched input stage and a simple hardware setup.

  11. Photonics for microwave systems and ultra-wideband signal processing

    Science.gov (United States)

    Ng, W.

    2016-08-01

    The advantages of using the broadband and low-loss distribution attributes of photonics to enhance the signal processing and sensing capabilities of microwave systems are well known. In this paper, we review the progress made in the topical areas of true-time-delay beamsteering, photonic-assisted analog-to-digital conversion, RF-photonic filtering and link performances. We also provide an outlook on the emerging field of integrated microwave photonics (MWP) that promise to reduce the cost of MWP subsystems and components, while providing significantly improved form-factors for system insertion.

  12. Location and Navigation with Ultra-Wideband Signals

    Science.gov (United States)

    2012-06-07

    obtaining the values of J(ñ0Tc) in the right frame where n0 is located, take the difference ∆J(ñ0Tc) = J(ñ0Tc)−J(ñ0Tc− wTc ), where w ∈ [1, Nc] and wTc ...beforehand. As illustrated in Fig. 3(a), the performance of the difference operation depends on the step size wTc . Accordingly, we choose the optimum...value for CM1 in our simulation as wTc = 3ns at low SNR and wTc = 8ns at high SNR. The normalized MSE for the SML algorithm with various K is plotted in

  13. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances.

    Science.gov (United States)

    Alarifi, Abdulrahman; Al-Salman, AbdulMalik; Alsaleh, Mansour; Alnafessah, Ahmad; Al-Hadhrami, Suheer; Al-Ammar, Mai A; Al-Khalifa, Hend S

    2016-05-16

    In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB) is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT) to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space.

  14. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances

    Directory of Open Access Journals (Sweden)

    Abdulrahman Alarifi

    2016-05-01

    Full Text Available In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space.

  15. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances †

    Science.gov (United States)

    Alarifi, Abdulrahman; Al-Salman, AbdulMalik; Alsaleh, Mansour; Alnafessah, Ahmad; Al-Hadhrami, Suheer; Al-Ammar, Mai A.; Al-Khalifa, Hend S.

    2016-01-01

    In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB) is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT) to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space. PMID:27196906

  16. Principles and Limitations of Ultra-Wideband FM Communications Systems

    Directory of Open Access Journals (Sweden)

    Kouwenhoven Michiel HL

    2005-01-01

    Full Text Available This paper presents a novel UWB communications system using double FM: a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low (1–10 kbps and medium (100–1000 kbps bit rate, and short-range WPAN systems. A wideband delay-line FM demodulator that is not preceded by any limiting amplifier constitutes the key component of the UWBFM receiver. This unusual approach permits multiple users to share the same RF bandwidth. Multipath, however, may limit the useful subcarrier bandwidth to one octave. This paper addresses the performance with AWGN and multipath, the resistance to narrowband interference, as well as the simultaneous detection of multiple FM signals at the same carrier frequency. SPICE and Matlab simulation results illustrate the principles and limitations of this new technology. A hardware demonstrator has been realized and has allowed the confirmation of theory with practical results.

  17. 75 FR 62476 - Ultra-Wideband Transmission Systems

    Science.gov (United States)

    2010-10-12

    ... to satellite digital television receivers in this band. Supporting comments were filed by Sprint Corporation (``Sprint'') and supporting reply comments were filed by Cingular and by SIA. Opposing comments... operating frequency, the duty cycle per channel is artificially increased to 100 percent and an...

  18. Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media

    Science.gov (United States)

    2016-03-04

    with the same material parameters as used in [5, 6]. The Fung-Ulaby model gives the relative dielectric permittivity as a mixing formula for water and...Varslot, J. H. Morales, M. Cheney, Waveform design for synthetic- aperture radar imaging through dispersive media, SIAM J. Appl. Math ., 71 (2011), pp. 1780...2010. [6] ——, “Waveform design for synthetic-aperture radar imaging through dispersive media,” SIAM J. Appl. Math ., vol. 71, no. 5, pp. 1780–1800, 2011

  19. Influence of the Antennas on the Ultra-Wideband Transmission

    Directory of Open Access Journals (Sweden)

    Werner Wiesbeck

    2005-03-01

    Full Text Available Spectrum is presently one of the most valuable goods worldwide as the demand is permanently increasing and it can be traded only locally. Since the United States Federal Communications Commission (FCC has opened the spectrum from 3.1 GHz to 10.6 GHz, that is, a bandwidth of 7.5 GHz, for unlicensed use with up to −41.25 dBm/MHz EIRP, numerous applications in communications and sensor areas are showing up. Like all wireless devices, these have an antenna as an integral part of the air interface. The antennas are modeled as linear time-invariant (LTI systems with a transfer function. The measurement of the antenna's frequency-dependent directional transfer function is described. Quality measures for the antennas like the peak value of the transient response, its width and ringing, as well as the transient gain are discussed. The application of these quality measures is shown for measurements of different UWB antennas.

  20. Ultra Wideband Wireless Body Area Network for Medical Applications

    Science.gov (United States)

    2010-04-01

    with a tuning uneven U-shape stub on LPC for microwave tumor detection,” in Proc. of Asia - Pacific Microwave Conf. (APMC), Bangkok, Thailand...monitoring in infants, obstructive sleep apnoea monitoring, allergy and asthma crisis monitoring, etc. The application of UWB radar in obstetrics as a

  1. Algorithms for Indoor Positioning Systems Using Ultra-Wideband Signals

    NARCIS (Netherlands)

    Yan , J.

    2010-01-01

    Positioning systems and techniques have attracted more and more attention in recent years, in particular with satellite navigation technology as a tremendous enabler, and developments in indoor navigation. The work presented in this thesis has been conducted within the research project: \\HERE:

  2. Ultra-Wideband Electromagnetic Induction for UXO Discrimination

    Science.gov (United States)

    2002-11-30

    prolate to oblate shapes do not present problematical considerations, we will just proceed below in terms of the prolate case. The coefficients bpmn in...these equations are known in the sense that they are calculated from the primary field, while the unknown Bpmn must be solved for. Obtaining the... Bpmn constitutes solving the problem, given that the associated Legendre functions m mn nandP Q are readily evaluated. A set of bpmn can be obtained

  3. Next Generation Ultra-Wideband (UWB) Intrusion Detection Radar.

    Science.gov (United States)

    2007-11-02

    Marine, Inc., Charlot- tesville, VA, which marketed the product to law enforcement agencies. The Small Business Administration, in their 5th Annual...A,= - --N,(2.3) so that the equation for determining peak power is given by: 4P 2 - 4G = P, =- watt. (2.4) Solving for the effective radiated power...computers now run- ning at a 100 MHz and high speed graphics cards becoming more prevalent for addressing com- mercial real-time video markets , it is

  4. Ultra-wideband, omni-directional, low distortion coaxial antenna

    Science.gov (United States)

    Eubanks, Travis Wayne; Gibson, Christopher Lawrence

    2015-01-06

    An antenna for producing an omni-directional pattern, and using all frequencies of a frequency range simultaneously, is provided with first and second electrically conductive elements disposed coaxially relative to a central axis. The first element has a first surface of revolution about the axis, the first surface of revolution tapering radially outwardly while extending axially away from the second element to terminate at a first axial end of the first element. The second element has a second surface of revolution about the axis, the second surface of revolution tapering radially outwardly while extending axially toward the first element to terminate at a first axial end of the second element. The first and second surfaces of revolution overlap one another radially and axially, and are mutually non-conformal.

  5. Compact Ultra-Wideband Optical Frequency Comb Fiber Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on our success in developing the world first commercial 10 W femtosecond fiber laser system and our leading technology development in ultrashort pulsed fiber...

  6. Long slot arrays - Part 2: Ultra wideband test results

    NARCIS (Netherlands)

    Lee, J.J.; Livingston, S.; Koenig, R.; Nagata, D.; Lai, L.; Neto, A.

    2005-01-01

    A wideband long slot array was recently developed for radar and EW applications. Theoretically the new design has unlimited bandwidth if no ground plane is included but at the expense of 3 dB loss in gain because of bi-directional radiation. In practice, however, a ground plane is used which limits

  7. Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

    2000-01-01

    to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very...

  8. Status of Low Thrust Work at JSC

    Science.gov (United States)

    Condon, Gerald L.

    2004-01-01

    High performance low thrust (solar electric, nuclear electric, variable specific impulse magnetoplasma rocket) propulsion offers a significant benefit to NASA missions beyond low Earth orbit. As NASA (e.g., Prometheus Project) endeavors to develop these propulsion systems and associated power supplies, it becomes necessary to develop a refined trajectory design capability that will allow engineers to develop future robotic and human mission designs that take advantage of this new technology. This ongoing work addresses development of a trajectory design and optimization tool for assessing low thrust (and other types) trajectories. This work targets to advance the state of the art, enable future NASA missions, enable science drivers, and enhance education. This presentation provides a summary of the low thrust-related JSC activities under the ISP program and specifically, provides a look at a new release of a multi-gravity, multispacecraft trajectory optimization tool (Copernicus) along with analysis performed using this tool over the past year.

  9. JSC “ALFA-BANK” marketing policy. problems and perspectives

    OpenAIRE

    Kirillov, A.; Kuznetcova, E.; Martirosian, M.

    2013-01-01

    The article is devoted to the results of JSC “Alfa-Bank” consumers’ segmentation and the following complex marketing research. The article suggests the ways of the bank’s marketing policy improvement.

  10. 3D Pattern Synthesis of Time-Modulated Conformal Arrays with a Multiobjective Optimization Approach

    Directory of Open Access Journals (Sweden)

    Wentao Li

    2014-01-01

    Full Text Available This paper addresses the synthesis of the three-dimensional (3D radiation patterns of the time-modulated conformal arrays. Due to the nature of periodic time modulation, harmonic radiation patterns are generated at the multiples of the modulation frequency in time-modulated arrays. Thus, the optimization goal of the time-modulated conformal array includes the optimization of the sidelobe level at the operating frequency and the sideband levels (SBLs at the harmonic frequency, and the design can be regarded as a multiobjective problem. The multiobjective particle swarm optimization (MOPSO is applied to optimize the switch-on instants and pulse durations of the time-modulated conformal array. To significantly reduce the optimization variables, the modified Bernstein polynomial is employed in the synthesis process. Furthermore, dual polarized patch antenna is designed as radiator to achieve low cross-polarization level during the beam scanning. A 12 × 13 (156-element conical conformal microstrip array is simulated to demonstrate the proposed synthesis mechanism, and good results reveal the promising ability of the proposed algorithm in solving the synthesis of the time-modulated conformal arrays problem.

  11. JSC Case Study: Fleet Experience with E-85 Fuel

    Science.gov (United States)

    Hummel, Kirck

    2009-01-01

    JSC has used E-85 as part of an overall strategy to comply with Presidential Executive Order 13423 and the Energy Policy Act. As a Federal fleet, we are required to reduce our petroleum consumption by 2 percent per year, and increase the use of alternative fuels in our vehicles. With the opening of our onsite dispenser in October 2004, JSC became the second federal fleet in Texas and the fifth NASA center to add E-85 fueling capability. JSC has a relatively small number of GSA Flex Fuel fleet vehicles at the present time (we don't include personal vehicles, or other contractor's non-GSA fleet), and there were no reasonably available retail E-85 fuel stations within a 15-minute drive or within five miles (one way). So we decided to install a small 1000 gallon onsite tank and dispenser. It was difficult to obtain a supplier due to our low monthly fuel consumption, and our fuel supplier contract has changed three times in less than five years. We experiences a couple of fuel contamination and quality control issues. JSC obtained good information on E-85 from the National Ethanol Vehicle Coalition (NEVC). We also spoke with Defense Energy Support Center, (DESC), Lawrence Berkeley Laboratory, and US Army Fort Leonard Wood. E-85 is a liquid fuel that is dispensed into our Flexible Fuel Vehicles identically to regular gasoline, so it was easy for our vehicle drivers to make the transition.

  12. Engineering massive quantum memories by topologically time-modulated spin rings

    CERN Document Server

    Giampaolo, S M; Lisi, A D; De Siena, S

    2005-01-01

    We introduce a scheme to realize the perfect storage of large sets of local quantum states in systems of interacting qubits. Such systems are described by spin rings with complex XY intersite couplings of suitably time-modulated phases. We show that initially localized excitations undergo perfect periodic revivals after a finite spread, allowing for the simultaneous storage of arbitrary sets of different local states. We also prove the reliability of the scheme in the presence of noise and imperfections both in the time modulation of the phases and in the magnitude of the interaction couplings.

  13. Technicians assembly the Hubble Space Telescope (HST) mockup at JSC

    Science.gov (United States)

    1989-01-01

    At JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A, technicians install a high gain antenna (HGA) on the Hubble Space Telescope (HST) mockup. On the ground a technician operates the controls for the overhead crane that is lifting the HGA into place on the Support System Module (SSM) forward shell. Others in a cherry picker basket wait for the HGA to near its final position so they can secure it on the mockup.

  14. STS-35 DTO 0634 EDO trash compactor demonstration at JSC

    Science.gov (United States)

    1990-01-01

    STS-35 Development Test Objective (DTO) 0634 Trash Compaction and Retention System Demostration extended duration orbiter (EDO) trash compactor is operated by Project Engineer Fred Abolfathi of Lockheed Engineering and Space Corporation (left) and JSC Man-Systems Division Subsystems Manager J.B. Thomas. The EDO trash compactor will occupy one middeck locker and consists of a geared mechanism that allows manual compaction of wet and dry trash.

  15. The JSC Engineering Directorate Product Peer Review Process

    Science.gov (United States)

    Jenks, Kenneth C.

    2009-01-01

    The JSC Engineering Directorate has developed a Product Peer Review process in support of NASA policies for project management and systems engineering. The process complies with the requirements of NPR 7120.5, NPR 7123.1 and NPR 7150.2 and follows the guidance in NASA/SP-2007-6105. This presentation will give an overview of the process followed by a brief demonstration of an actual peer review, with audience participation.

  16. Adsorption of Water on JSC-1A Lunar Simulant Samples

    Science.gov (United States)

    Goering, John; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W.

    2008-01-01

    Remote sensing probes sent to the moon in the 1990s indicated that water may exist in areas such as the bottoms of deep, permanently shadowed craters at the lunar poles, buried under regolith. Water is of paramount importance for any lunar exploration and colonization project which would require self-sustainable systems. Therefore, investigating the interaction of water with lunar regolith is pertinent to future exploration. The lunar environment can be approximated in ultra-high vacuum systems such as those used in thermal desorption spectroscopy (TDS). Questions about water dissociation, surface wetting, degree of crystallization, details of water-ice transitions, and cluster formation kinetics can be addressed by TDS. Lunar regolith specimens collected during the Apollo missions are still available though precious, so testing with simulant is required before applying to use lunar regolith samples. Hence, we used for these studies JSC-1a, mostly an aluminosilicate glass and basaltic material containing substantial amounts of plagioclase, some olivine and traces of other minerals. Objectives of this project include: 1) Manufacturing samples using as little raw material as possible, allowing the use of surface chemistry and kinetics tools to determine the feasibility of parallel studies on regolith, and 2) Characterizing the adsorption kinetics of water on the regolith simulant. This has implications for the probability of finding water on the moon and, if present, for recovery techniques. For condensed water films, complex TDS data were obtained containing multiple features, which are related to subtle rearrangements of the water adlayer. Results from JSC-1a TDS studies indicate: 1) Water dissociation on JSC-1a at low exposures, with features detected at temperatures as high as 450 K and 2) The formation of 3D water clusters and a rather porous condensed water film. It appears plausible that the sub- m sized particles act as nucleation centers.

  17. STS-47 crew extinquishes fire during JSC fire fighting exercises

    Science.gov (United States)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, crewmembers lined up along water hoses direct spray at fire blazing in JSC's Fire Training Pit. At the left are backup Payload Specialist Stan Koszelak, holding the hose nozzle, and Mission Specialist (MS) N. Jan Davis. Manning the hose on the right are backup Payload Specialist Takao Doi, holding the hose nozzle, followed by Commander Robert L. Gibson, Payload Specialist Mamoru Mohri, and MS Jerome Apt. Guiding the teams are MS Mae C. Jemison (front) and a veteran fire fighter and instructor (center). Doi and Mohri represent Japan's National Space Development Agency (NASDA). The Fire Training Pit is located across from the Gilruth Center Bldg 207.

  18. Organic Contamination Baseline Study on NASA JSC Astromaterial Curation Gloveboxes

    Science.gov (United States)

    Calaway, Michael J.; Allton, J. H.; Allen, C. C.; Burkett, P. J.

    2013-01-01

    Future planned sample return missions to carbon-rich asteroids and Mars in the next two decades will require strict handling and curation protocols as well as new procedures for reducing organic contamination. After the Apollo program, astromaterial collections have mainly been concerned with inorganic contamination [1-4]. However, future isolation containment systems for astromaterials, possibly nitrogen enriched gloveboxes, must be able to reduce organic and inorganic cross-contamination. In 2012, a baseline study was orchestrated to establish the current state of organic cleanliness in gloveboxes used by NASA JSC astromaterials curation labs that could be used as a benchmark for future mission designs.

  19. Human Spaceflight Technology Needs - A Foundation for JSC's Technology Strategy

    Science.gov (United States)

    Stecklein, Jonette M.

    2013-01-01

    Human space exploration has always been heavily influenced by goals to achieve a specific mission on a specific schedule. This approach drove rapid technology development, the rapidity of which adds risks as well as provides a major driver for costs and cost uncertainty. The National Aeronautics and Space Administration (NASA) is now approaching the extension of human presence throughout the solar system by balancing a proactive yet less schedule-driven development of technology with opportunistic scheduling of missions as the needed technologies are realized. This approach should provide cost effective, low risk technology development that will enable efficient and effective manned spaceflight missions. As a first step, the NASA Human Spaceflight Architecture Team (HAT) has identified a suite of critical technologies needed to support future manned missions across a range of destinations, including in cis-lunar space, near earth asteroid visits, lunar exploration, Mars moons, and Mars exploration. The challenge now is to develop a strategy and plan for technology development that efficiently enables these missions over a reasonable time period, without increasing technology development costs unnecessarily due to schedule pressure, and subsequently mitigating development and mission risks. NASA's Johnson Space Center (JSC), as the nation s primary center for human exploration, is addressing this challenge through an innovative approach in allocating Internal Research and Development funding to projects. The HAT Technology Needs (TechNeeds) Database has been developed to correlate across critical technologies and the NASA Office of Chief Technologist Technology Area Breakdown Structure (TABS). The TechNeeds Database illuminates that many critical technologies may support a single technical capability gap, that many HAT technology needs may map to a single TABS technology discipline, and that a single HAT technology need may map to multiple TABS technology

  20. Reducing Organic Contamination in NASA JSC Astromaterial Curation Facility

    Science.gov (United States)

    Calaway, M. J.; Allen, C. C.; Allton, J. H.

    2013-01-01

    Future robotic and human spaceflight missions to the Moon, Mars, asteroids and comets will require handling and storing astromaterial samples with minimal inorganic and organic contamination to preserve the scientific integrity of each sample. Much was learned from the rigorous attempts to minimize and monitor organic contamination during Apollo, but it was not adequate for current analytical requirements; thus [1]. OSIRIS-REx, Hayabusa-2, and future Mars sample return will require better protocols for reducing organic contamination. Future isolation con-tainment systems for astromaterials, possibly nitrogen enriched gloveboxes, must be able to reduce organic and inorganic cross-contamination. In 2012, a baseline study established the current state of organic cleanliness in gloveboxes used by NASA JSC astromaterials curation labs that could be used as a benchmark for future mission designs [2, 3]. After standard ultra-pure water (UPW) cleaning, the majority of organic contaminates found were hydrocarbons, plasticizers, silicones, and solvents. Hydro-carbons loads (> C7) ranged from 1.9 to 11.8 ng/cm2 for TD-GC-MS wafer exposure analyses and 5.0 to 19.5 ng/L for TD-GC-MS adsorbent tube exposure. Plasticizers included nano grade solution), and heat sterilization at 130degC for 48 hours to reduce organic contamination. In addition, both heat sterilization and peracetic acid sterilization were used in the atmospheric de-contamination (R) cabinets. Later, Lunar curation gloveboxes were degreased with a pressurized Freon 113 wash. Today, UPW has replaced Freon as the standard cleaning procedure, but does not have the degreasing solvency power of Freon. Future Cleaning Studies: Cleaning experiments are cur-rently being orchestrated to study how to degrease and reduce organics in a JSC curation glovebox lower than the established baseline. Several new chemicals in the industry have replaced traditional degreasing solvents such as Freon and others that are now federally

  1. The JSC Research and Development Annual Report 1993

    Science.gov (United States)

    1994-01-01

    Issued as a companion to Johnson Space Center's Research and Technology Annual Report, which reports JSC accomplishments under NASA Research and Technology Operating Plan (RTOP) funding, this report describes 47 additional projects that are funded through sources other than the RTOP. Emerging technologies in four major disciplines are summarized: space systems technology, medical and life sciences, mission operations, and computer systems. Although these projects focus on support of human spacecraft design, development, and safety, most have wide civil and commercial applications in areas such as advanced materials, superconductors, advanced semiconductors, digital imaging, high density data storage, high performance computers, optoelectronics, artificial intelligence, robotics and automation, sensors, biotechnology, medical devices and diagnosis, and human factors engineering.

  2. [Taylor and Hill, Incorporated's JSC Cryo Chamber A

    Science.gov (United States)

    Morales, Rito

    2008-01-01

    NASA commissioned construction of an environmental simulation test chamber which was completed in 1964 at Johnson Space Center (JSC) in Houston, Texas. The facility, Chamber A, was invaluable for testing spacecraft and satellites before deployment to space. By testing spacecraft in an environment similar to the one they would be functioning in, potential problems could be addressed before launch. A new addition to NASA's observatory inventory is called the James Webb Space Telescope (JWST), after a former Administrator of NASA. The new telescope will have 7 times the mirror area of the Hubble, with a target destination approximately one million miles from earth. Scheduled for launch in 2013, the JWST will allow scientists the ability to see, for the first time, the first galaxies that formed in the early Universe. Pre-launch testing of JWST must be performed in environments that approximate its final target space environment as closely as possible.

  3. STS-26 crew in JSC Shuttle Mockup and Integration Laboratory

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers have donned their new (navy blue) partial pressure suits (launch and entry suits (LESs)) for a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Commander Frederick H. Hauck is in the center foreground. Hauck is flanked by fellow crewmembers (left to right) Mission Specialist (MS) John M. Lounge, MS George D. Nelson, Pilot Richard O. Covey, and MS David C. Hilmers. Astronaut Steven R. Nagel, not assigned as crewmember but assisting in training, is at far right. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  4. Novel differential unitary space-time modulation schemes for fast fading channels

    Institute of Scientific and Technical Information of China (English)

    Tian Jifeng; Jiang Haining; Song Wentao; Luo Hanwen

    2006-01-01

    Differential unitary space-time modulation (DUSTM), which obtains full transmit diversity in slowly flat-fading channels without channel state information, has generated significant interests recently. To combat frequency-selective fading, DUSTM has been applied to each subcarrier of an OFDM system and DUSTM-OFDM system was proposed. Both DUSTM and DUSTM-OFDM, however, are designed for slowly fading channels and suffer performance deterioration in fast fading channels. In this paper, two novel differential unitary space-time modulation schemes are proposed for fast fading channels. For fast flat-fading channels, a sub-matrix interleaved DUSTM (SMI-DUSTM) scheme is proposed, in which matrix-segmentation and sub-matrix based interleaving are introduced into DUSTM system. For fast frequency-selective fading channels, a differential unitary space-frequency modulation (DUSFM) scheme is proposed, in which existing unitary space-time codes are employed across transmit antennas and OFDM subcarriers simultaneously and differential modulation is performed between two adjacent OFDM blocks. Compared with DUSTM and DUSTM-OFDM schemes, SMI-DUSTM and DUSFM-OFDM are more robust to fast channel fading with low decoding complexity, which is demonstrated by performance analysis and simulation results.

  5. A Time Modulated Printed Dipole Antenna Array for Beam Steering Application

    Directory of Open Access Journals (Sweden)

    Ruchi Gahley

    2017-01-01

    Full Text Available This paper presents time modulated beam steered antenna array without phase shifters. The beam steering is analyzed considering a two-element time modulated antenna array (TMAA of printed dipoles with microstrip via-hole balun. The proposed array resonates at the Industrial, Scientific, and Medical (ISM radio bands, 2.45 GHz and 5.8 GHz, and offers wide bandwidth inherited due to modified structure of ground plane. Array elements are excited by complex exponential excitation signal through broadband power divider and radio frequency (RF switches to achieve amplitude and phase variation without phase shifters. Differential Evolution algorithm is used to modify the time sequences of the RF switches connected to the antennas to generate radiation pattern with optimum dynamic efficiency by suppressing sideband radiations. Also switch-on time instant of RF switch connected to the subsequent element is modulated to steer the beam towards different directions. The proposed prototype is fabricated followed by parametric optimization. The fabrication results agree significantly well with simulated results.

  6. STS-29 Discovery, OV-103, MS Springer on JSC crew compartment trainer middeck

    Science.gov (United States)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Robert C. Springer, wearing navy blue launch and entry suit (LES) and launch and entry helmet (LEH), participates in JSC crew compartment trainer (CCT) exercises. MS Springer is seated in mission specialist seat on CCT middeck, the position he will occupy during the entry phase of flight. Behind Springer is the closed airlock hatch and stowed treadmill. The crew escape system (CES) pole extends overhead from starboard wall to side hatch. On Springer's left is the galley. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  7. Information transfer via implicit encoding with delay time modulation in a time-delay system

    Energy Technology Data Exchange (ETDEWEB)

    Kye, Won-Ho, E-mail: whkye@kipo.go.kr [Korean Intellectual Property Office, Government Complex Daejeon Building 4, 189, Cheongsa-ro, Seo-gu, Daejeon 302-701 (Korea, Republic of)

    2012-08-20

    A new encoding scheme for information transfer with modulated delay time in a time-delay system is proposed. In the scheme, the message is implicitly encoded into the modulated delay time. The information transfer rate as a function of encoding redundancy in various noise scales is presented and it is analyzed that the implicit encoding scheme (IES) has stronger resistance against channel noise than the explicit encoding scheme (EES). In addition, its advantages in terms of secure communication and feasible applications are discussed. -- Highlights: ► We propose new encoding scheme with delay time modulation. ► The message is implicitly encoded with modulated delay time. ► The proposed scheme shows stronger resistance against channel noise.

  8. Mixer-Duplexer-Antenna Leaky-Wave System Based on Periodic Space-Time Modulation

    CERN Document Server

    Taravati, Sajjad

    2016-01-01

    We present a mixer-duplexer-antenna leaky-wave system based on periodic space-time modulation. This system operates as a full transceiver, where the upconversion and downconversion mixing operations are accomplished via space-time transitions, the duplexing operation is induced by the nonreciprocal nature of the structure, and the radiation operation is provided by the leaky-wave nature of the wave. A rigorous electromagnetic solution is derived for the dispersion relation and field distributions. The system is implemented in the form of a spatio-temporally modulated microstrip leaky-wave structure incorporating an array of sub-wavelengthly spaced varactors modulated by a harmonic wave. In addition to the overall mixer-duplexer-antenna operation, frequency beam scanning at fixed input frequency is demonstrated as one of the interesting features of the system. A prototype is realized and demonstrated by full-wave and experimental results.

  9. Differential space-time modulation based on orthogonal design for cooperative network

    Institute of Scientific and Technical Information of China (English)

    Ding Sheng; Yan Kai; Qiu Yunzhou; Zhu Minghua; Liu Haitao

    2008-01-01

    Differential modulation was widely used for wireless networks in which channel estimation was difficult. Based on orthogonal design, a novel distributed differential space-time coding/decoding scheme for M-PSK modulations was proposed, which had a high code rate of 2/3 and second-order diversity for the two-user cooperative networks. The performance of decode-and-forward (DF) protocols was evaluated. Simulations show that the differential space-time modulation scheme in this paper has better bit error rate (BER) performance or higher code rate than the schemes proposed by Tarasak and Wang when interuser channel states are good enough. The impacts of transmission error between two users for the whole system BER performance were also investigated.

  10. Astronaut Kenneth D. Cameron in T-38A cockpit at Ellington Field near JSC

    Science.gov (United States)

    1989-01-01

    Astronaut Kenneth D. Cameron seated in the forward cockpit of a T-38A conducts preflight checkout procedures at Ellington Field near JSC. Cameron is preparing for a flight to Fairchild Air Force Base (AFB) in Spokane, Washington.

  11. STS-30 crewmembers pose for informal portrait on JSC FB-SMS middeck

    Science.gov (United States)

    1988-01-01

    STS-30 Atlantis, Orbiter Vehicle (OV) 104, crewmembers pause briefly from their training schedule to pose for informal portrait in JSC fixed base (FB) shuttle mission simulator (SMS). On FB-SMS middeck are (left to right) Commander David M. Walker, Mission Specialist (MS) Mark C. Lee, MS Mary L. Cleave, Pilot Ronald J. Grabe, and MS Norman E. Thagard. FB-SMS is located in JSC's Mission Simulation and Training Facility Bldg 5.

  12. Human Thermal Model Evaluation Using the JSC Human Thermal Database

    Science.gov (United States)

    Bue, Grant; Makinen, Janice; Cognata, Thomas

    2012-01-01

    Human thermal modeling has considerable long term utility to human space flight. Such models provide a tool to predict crew survivability in support of vehicle design and to evaluate crew response in untested space environments. It is to the benefit of any such model not only to collect relevant experimental data to correlate it against, but also to maintain an experimental standard or benchmark for future development in a readily and rapidly searchable and software accessible format. The Human thermal database project is intended to do just so; to collect relevant data from literature and experimentation and to store the data in a database structure for immediate and future use as a benchmark to judge human thermal models against, in identifying model strengths and weakness, to support model development and improve correlation, and to statistically quantify a model s predictive quality. The human thermal database developed at the Johnson Space Center (JSC) is intended to evaluate a set of widely used human thermal models. This set includes the Wissler human thermal model, a model that has been widely used to predict the human thermoregulatory response to a variety of cold and hot environments. These models are statistically compared to the current database, which contains experiments of human subjects primarily in air from a literature survey ranging between 1953 and 2004 and from a suited experiment recently performed by the authors, for a quantitative study of relative strength and predictive quality of the models.

  13. Target Recognition Using Late-Time Returns from Ultra-Wideband, Short-Pulse Radar

    Science.gov (United States)

    2004-06-01

    WIDEBAND, SHORT-PULSE RADAR DISSERTATION Kenneth J. Pascoe, B.S.E.E., M.S. Major, USAF Approved: Dr. Michael J. Havrilla Dissertation Advisor Date Dr...Acknowledgments Thanks to all the people who helped to make this research happen. Thanks to my committee: Dr. Michael Havrilla , the late Major Bill Wood...Singularity Expansion Method 16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON Michael J. Havrilla , Ph.D. (ENG) a. REPORT U b

  14. Multi-pulse frequency shifted (MPFS) multiple access modulation for ultra wideband

    Science.gov (United States)

    Nekoogar, Faranak [San Ramon, CA; Dowla, Farid U [Castro Valley, CA

    2012-01-24

    The multi-pulse frequency shifted technique uses mutually orthogonal short duration pulses o transmit and receive information in a UWB multiuser communication system. The multiuser system uses the same pulse shape with different frequencies for the reference and data for each user. Different users have a different pulse shape (mutually orthogonal to each other) and different transmit and reference frequencies. At the receiver, the reference pulse is frequency shifted to match the data pulse and a correlation scheme followed by a hard decision block detects the data.

  15. Theoretical study of ultra-wideband slow light in dual-stub-coupled plasmonic waveguide

    Science.gov (United States)

    Li, Chunlei; Su, Runzhou; Wang, Yuxiao; Zhang, Xueru

    2016-10-01

    We propose and demonstrate a metal-insulator-metal (MIM) waveguide side coupled double stubs to realize broadband slow surface plasmon polaritons (SPPs) around the telecom frequency 193.5 THz. When the depth of single stub is approximately equal to integral multiple of half plasmon wavelength, owing to the constructive interferences between the electromagnetic wave propagating through the MIM waveguide and that reflected from the stubs, wideband slow light effect appears. The improved transmission line theory calculation indicates that the group velocity of SPPs in the plasmonic waveguide system for stub depth 1111 nm is 0.1c (c is light speed in vacuum.) over a broad bandwidth of 69 THz. Exploiting the finite-difference time-domain (FDTD) numerical simulation, the group velocity of pulse for width 20 fs (Full width at half high) is calculated. The result agrees well with that predicted by the transmission line theory. This plasmonic waveguide for slow light effect has important potential application in optical delay lines.

  16. High-speed ultra-wideband wireless signals over fiber systems: Photonic generation and DSP detection

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We firstly review the efforts in the literature on UWB over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduce the use of digi...... of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

  17. Short-Range Ultra-Wideband Imaging with Multiple-Input Multiple-Output Arrays

    NARCIS (Netherlands)

    Zhuge, X.

    2010-01-01

    Compact, cost-efficient and high-resolution imaging sensors are especially desirable in the field of short-range observation and surveillance. Such sensors are of great value in fields of security, rescue and medical applications. Systems can be formed for various practical purposes, such as detecti

  18. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  19. Ultra-wideband phased array antennas for low frequency radio astronomy

    OpenAIRE

    Lera Acedo, Eloy de

    2011-01-01

    Esta tesis se centra en el desarrollo de antenas diferenciales de banda ultra ancha para arrays de apertura, como los que han sido propuestos por el consorcio internacional para cubrir las bandas bajas de frecuencia del telescopio (SKA-AAlo (0.07-0.45 GHz) y SKA-AAhi (0.3-1 GHz)). La tesis comienza con una introducción al campo de la radioastronomía y una presentación del estado del arte de la teoría y las tecnologías de arrays de antenas de banda ultra ancha para radioastronomía. Los capítul...

  20. Progress on Ultra-Wideband (UWB Multi-Antenna radar imaging for MIGA

    Directory of Open Access Journals (Sweden)

    Yedlin Matthew

    2016-01-01

    Full Text Available Progress on the development of the multi-channel, ground penetrating radar imaging system is presented from hardware and software perspectives. A new exponentially tapered slot antenna, with an operating bandwidth from 100 MHz to 1.5 GHz was fabricated and tested using the eight-port vector network analyzer, designed by Rhode and Schwarz Incorporated for this imaging project. An eight element antenna array mounted on two carts with automatic motor drive, was designed for optimal common midpoint (CMP data acquisition. Data acquisition scenarios were tested using the acoustic version of the NORSAR2D seismic ray-tracing software. This package enables the synthesis and analysis of multi-channel, multi-offset data acquisitions comprising more than a hundred thousand traces. Preliminary processing is in good agreement with published bistatic ground-penetrating radar images obtained in the tunnels of the Low-noise Underground Laboratory (LSBB at Rustrel, France.

  1. An Ultra-Wideband Cross-Correlation Radiometer for Mesoscopic Experiments

    Science.gov (United States)

    Toonen, Ryan; Haselby, Cyrus; Qin, Hua; Eriksson, Mark; Blick, Robert

    2007-03-01

    We have designed, built and tested a cross-correlation radiometer for detecting statistical order in the quantum fluctuations of mesoscopic experiments at sub-Kelvin temperatures. Our system utilizes a fully analog front-end--operating over the X- and Ku-bands (8 to 18 GHz)--for computing the cross-correlation function. Digital signal processing techniques are used to provide robustness against instrumentation drifts and offsets. The economized version of our instrument can measure, with sufficient correlation efficiency, noise signals having power levels as low as 10 fW. We show that, if desired, we can improve this performance by including cryogenic preamplifiers which boost the signal-to-noise ratio near the signal source. By adding a few extra components, we can measure both the real and imaginary parts of the cross-correlation function--improving the overall signal-to-noise ratio by a factor of sqrt[2]. We demonstrate the utility of our cross-correlator with noise power measurements from a quantum point contact.

  2. Ultra-Wideband Transceiver for Integrated Communication and Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many space missions require relative navigation between several spacecraft systems or between spacecraft and rovers or remote controlled probes, such as spacecraft...

  3. 2nd International Conference on Ultra-Wideband, Short-Pulse Electromagnetics

    CERN Document Server

    Felsen, Leopold

    1995-01-01

    The papers published in this volume were presented at the Second International Conference on Ultra-WidebandiShort-Pulse (UWB/SP) Electromagnetics, ApriIS-7, 1994. To place this second international conference in proper perspective with respect to the first conference held during October 8-10, 1992, at Polytechnic University, some background information is necessary. As we had hoped, the first conference struck a responsive cord, both in timeliness and relevance, among the electromagnetic community 1. Participants at the first conference already inquired whether and when a follow-up meeting was under consideration. The first concrete proposal in this direction was made a few months after the first conference by Prof. A. Terzuoli of the Air Force Institute of Technology (AFIT), Dayton, Ohio, who has been a strong advocate of time-domain methods and technologies. He initially proposed a follow-up time-domain workshop under AFIT auspices. Realizing that interest in this subject is lodged also at other Air Force i...

  4. Ultra-Wideband Impulse Radio for Tactical Ad-Hoc Military Communications

    Science.gov (United States)

    2010-09-02

    21], [23]. Rather than using simulations to show the bit-error- probability ( BEP ) performance with MAI as found in [14] and [15], we incorporate...the power 4 delay profile (PDP) of the channel, inspired by the work in [13], to derive the variance of the MAI, enabling theoretical BEP analysis. Our...an upper bound on the BEP , the number of equal-power users that the system can support is evaluated for different modulation order M. The network

  5. Range extension and channel capacity increase in impulse-radio ultra-wideband communications

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Yu, Xianbin; Caballero Jambrina, Antonio

    2010-01-01

    and its performance is compared. By utilizing optimum UWB pulse design and employing a digital signal processing (DSP) receiver, a bit-error-rate above the forward error correction (FEC) limit for 8 meters of wireless emission is obtained in our photonic generation UWB system. A noticeable increase...

  6. Ultra-Wideband Multi-Dye-Sensitized Upconverting Nanoparticles for Information Security Application.

    Science.gov (United States)

    Lee, Jongha; Yoo, Byeongjun; Lee, Hakyong; Cha, Gi Doo; Lee, Hee-Su; Cho, Youngho; Kim, Sang Yeon; Seo, Hyunseon; Lee, Woongchan; Son, Donghee; Kang, Myungjoo; Kim, Hyung Min; Park, Yong Il; Hyeon, Taeghwan; Kim, Dae-Hyeong

    2017-01-01

    Multi-dye-sensitized upconverting nanoparticles (UCNPs), which harvest photons of wide wavelength range (450-975 nm) are designed and synthesized. The UCNPs embedded in a photo-acid generating layer are integrated on destructible nonvolatile resistive memory device. Upon illumination of light, the system permanently erases stored data, achieving enhanced information security.

  7. High-Speed Turbo-TCM-Coded Orthogonal Frequency-Division Multiplexing Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available One of the UWB proposals in the IEEE P802.15 WPAN project is to use a multiband orthogonal frequency-division multiplexing (OFDM system and punctured convolutional codes for UWB channels supporting a data rate up to 480 Mbps. In this paper, we improve the proposed system using turbo TCM with QAM constellation for higher data rate transmission. We construct a punctured parity-concatenated trellis codes, in which a TCM code is used as the inner code and a simple parity-check code is employed as the outer code. The result shows that the system can offer a much higher spectral efficiency, for example, 1.2 Gbps, which is 2.5 times higher than the proposed system. We identify several essential requirements to achieve the high rate transmission, for example, frequency and time diversity and multilevel error protection. Results are confirmed by density evolution.

  8. Receiving and Detection of Ultra-Wideband Microwave Signals Radiated by Pulsed Excitation of Monopole Antennas

    Directory of Open Access Journals (Sweden)

    Steponas AŠMONTAS

    2014-06-01

    Full Text Available Pulsed excitation of small size monopole antennas for generating wideband electromagnetic pulses was used. The monopoles were excited by electrical pulses having rise times of 600 ps, 200 ps, 70 ps and voltages 100 V, 15 V, and 0.4 V respectively. Antennas spanning (0.3 – 26 GHz bandwidth, including broadband horns with coaxial outputs, were employed to receive signals, which were investigated using (0 – 26 GHz passband sampling oscilloscope. It was found that waveforms of signals, received by the antennas, mostly depend on the pulse rise time and on the details of geometry of monopoles. The electromagnetic pulses have relatively long duration of about 30 ns and spectral harmonics up to 22 GHz. Therefore they can be attributed to pulses with large base. The results show that the upper frequencies of the spectrum most probably are cut off by existing arrangement. Usage of such pulses can find wide practical application when they are received after transmission trough different media by a number of antennas having different operational frequency ranges, followed by digital signal processing. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.6330

  9. An ultra-wideband CMOS PA with dummy filling for reliability

    Science.gov (United States)

    Chang, Yu-Ting; Ye, Yu; Xu, Hongtao; Domier, Calvin; Luhmann, N. C.; Gu, Q. Jane

    2017-03-01

    A V-band power amplifier in a bulk 65 nm CMOS technology with a peak gain 14.5 dB and 3-dB bandwidth of 28.8 GHz (50.8-79.6 GHz) is presented. The techniques to boost bandwidth and power efficiency are presented. In addition, the design of dummy filling to satisfy manufacturing density requirements while having negligible effects on performances is discussed in details. The PA features a three stage transformer coupled differential architecture with integrated input and output baluns on-chip. The PA achieves a measured saturated output power of 15.1 dBm and output 1 dB compression power of 12.9 dBm at 65 GHz. The peak power-added efficiency is 18.9%. The entire PA occupies area of 0.31 mm2, while consuming 150 mW from a 1.25 V supply.

  10. Experimental demonstration of ultra-wideband and high-efficiency terahertz spoof surface plasmon polaritons coupler

    Science.gov (United States)

    Tang, Heng-He; Ma, Tian-Jun; Liu, Pu-Kun

    2016-05-01

    Spoof surface plasmon polaritons (SSPPs) are promising for subwavelength waveguiding in the terahertz (THz) frequency range. However, they cannot be efficiently excited from spatial propagating or guided waves due to the mismatched momenta. In this paper, a THz coupler is designed to smoothly bridge SSPPs and guided (or propagating) waves. By using a tapered parallel-plate waveguide, the incident energies are efficiently compressed and coupled into a subwavelength gap. Then, the momenta differences are mitigated with a graded grating. The numerical simulations show that the relative bandwidth of the coupler reaches up to 127%, and the maximum coupling efficiency is 99%. More importantly, experiment results in the 0.22 THz-0.33 THz frequency range are also presented to verify the good performance of the coupler. The work provides a technical support for terahertz waveguiding.

  11. A high-speed Schottky detector for ultra-wideband communications

    DEFF Research Database (Denmark)

    Valdecasa, Guillermo Silva; Cimoli, Bruno; Blanco Granja, Ángel;

    2017-01-01

    of the detector performance. The designed circuit is reviewed and measurements are provided for a manufactured prototype. The detector can successfully demodulate 2.5 Gbps video signals around a 7 GHz carrier. The bitrate to carrier frequency ratio of 35.7% is the highest reported for detectors at UWB frequencies......This letter reviews the design procedure of a high‐speed Schottky video detector for high‐data‐rate communications within the ultra‐wideband (UWB) frequencies. The classic design approach for video detectors is extended with a mixer‐like analysis, which results in a more detailed assessment...

  12. High Voltage Properties of Insulating Materials Measured in the Ultra Wideband

    Science.gov (United States)

    2005-06-01

    2.287 3.80 VRI 704 2.516 2.00 Dolphon 1.763 15.00 Conathane 2.265 2.80 Ultem 1000 2.879 3.15 Rexolite 2.069 2.53 Udel 2.755 4.10 Pomalux 2.755 3.80...spec 1 MHz Epoxy 815c/3140 3.73 -- VRI 704 4.00 -- Dolphon 1.10E+07 -- Conathane 4.81E+01 2.80E-02 Ultem 1.72 4.09E-03 Rexolite 1.35 3.04E-04 Udel...815c/3140 none 37 none 266.4 2664 -- VRI 70 23 27 165.6 194.4 1944 2692.4 Conathane 22 27 158.4 194.4 1944 609.6 Ultem 1000 29 33 208.8 237.6 2376

  13. A Baseband, Impulse Ultra-Wideband Transceiver Front-end for Low Power Applications

    Science.gov (United States)

    2006-05-08

    Jim Young , and Roy Sutton who had a similar long, strange road to travel. Here’s to the end and what lies beyond. I also would like to thank ST...taken at “plusN” ( modulo 32) from the DLL phases to generate the output control. For example, if phase N is “plus00” and starts sampling (ending reset...Berkeley, Berkeley, CA, 1990. [107] I. A. Young , J. K. Greason, and K. L. Wong, “A pll clock generator with 5 to 110 mhz of lock range for

  14. Human Motion Recognition Using Ultra-Wideband Radar and Cameras on Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    LI Tuanjie; GE Mengmeng

    2009-01-01

    Cameras can reliably detect human motions in a normal environment, but they are usually affected by sudden illumination changes and complex conditions, which are the major obstacles to the reliability and robustness of the system. To solve this problem, a novel integration method was proposed to combine bi-static uitra-wideband radar and cameras. In this recognition system, two cameras are used to localize the object's region, regions while a radar is used to obtain its 3D motion models on a mobile robot. The recognition results can be matched in the 3D motion library in order to recognize its motions. To confirm the effectiveness of the proposed method, the experi-mental results of recognition using vision sensors and those of recognition using the integration method were com-pared in different environments. Higher correct-recognition rate is achieved in the experiment.

  15. Ultra-wideband and broad-angle linear polarization conversion metasurface

    Science.gov (United States)

    Sun, Hengyi; Gu, Changqing; Chen, Xinlei; Li, Zhuo; Liu, Liangliang; Martín, Ferran

    2017-05-01

    In this work, a metasurface acting as a linear polarization rotator, that can efficiently convert linearly polarized electromagnetic waves to cross polarized waves within an ultra wide frequency band and with a broad incident angle, is proposed. Based on the electric and magnetic resonant features of the unit cell, composed by a double-head arrow, a cut-wire, and two short V-shaped wire structures, three resonances, which lead to the bandwidth expansion of cross-polarization reflections, are generated. The simulation results show that an average polarization conversion ratio of 90% from 17.3 GHz to 42.2 GHz can be achieved. Furthermore, the designed metasurface exhibits polarization insensitivity within a broad incident angle, from 0° to 50°. The experiments conducted on the fabricated metasurface are in good agreement with the simulations. The proposed metasurface can find potential applications in reflector antennas, imaging systems, and remote sensors operating at microwave frequencies.

  16. Self organization of wireless sensor networks using ultra-wideband radios

    Science.gov (United States)

    Dowla, Farid U.; Nekoogar, Franak; Spiridon, Alex

    2009-06-16

    A novel UWB communications method and system that provides self-organization for wireless sensor networks is introduced. The self-organization is in terms of scalability, power conservation, channel estimation, and node synchronization in wireless sensor networks. The UWB receiver in the present invention adds two new tasks to conventional TR receivers. The two additional units are SNR enhancing unit and timing acquisition and tracking unit.

  17. Trapped-Victim Detection in Post-Disaster Scenarios using Ultra-Wideband Radar

    NARCIS (Netherlands)

    Nezirović, A.N.

    2010-01-01

    Rescue dogs are commonly used during the urban search-and-rescue (USAR) operations for the initial indication on the presence of trapped victims after the collapse of man-made structures. However, dogs are not able to inform the rescue crews whether the trapped victims are alive or not and where exa

  18. A Rugged Ultra-Wideband (UWB) Circular Planar Monopole for Multichannel Radar

    Science.gov (United States)

    2016-03-01

    ordered metallic enclosure is made of welded aluminum measuring 12 inches x 12 inches x 5 inches x 3 32 inch (with respect to the inside). The...issues that became apparent in designing the baseline. Substituting a welded aluminum enclosure for the intended plastic enclosure solved the...performance of the fabricated antenna. The outer conductor had to be kept isolated from the walls of the enclosure while maintaining a rigid structure, so a

  19. The National Geoelectromagnetic Facility - an open access resource for ultra wideband electromagnetic geophysics (Invited)

    Science.gov (United States)

    Schultz, A.; Urquhart, S.; Slater, M.

    2010-12-01

    At present, the US academic community has access to two national electromagnetic (EM) instrument pools that support long-period magnetotelluric (MT) equipment suitable for crust-mantle scale studies. The requirements of near surface geophysics, hydrology, glaciology, as well as the full range of crust and mantle investigations require development of new capabilities in data acquisition with broader frequency bandwidth than these existing units, increased instrument numbers, and concomitant developments in 3D/4D data interpretation. NSF Major Research Instrumentation support has been obtained to meet these requirements by developing an initial set of next-generation instruments as a National Geoelectromagnetic Facility (NGF), available to all PIs on a cost recovery basis, and operated by Oregon State University (OSU). In contrast to existing instruments with data acquisition systems specialized to operate within specific frequency bands and for specific electromagnetic methods, the NGF model "Zen/5" instruments being co-developed by OSU and Zonge Research and Engineering Organization are based on modular receivers with a flexible number of digital and analog input channels, designed to acquire EM data at dc, and from frequencies ranging from micro-Hz to MHz. These systems can be deployed in a compact, low power configuration for extended deployments (e.g. for crust-mantle scale experiments), or in a high frequency sampling mode for near surface work. The NGF is also acquiring controlled source EM transmitters, so that investigators may carry out magnetotelluric, audio-MT, radiofrequency-MT, as well as time-domain/transient EM and DC resistivity studies. The instruments are designed to simultaneously accommodate multiple electric field dipole sensors, magnetic fluxgates and induction coil sensors. Sample rates as high as 2.5 MHz with resolution between 24 and 32 bits, depending on sample rate, are specified to allow for high fidelity recording of waveforms. The NGF is accepting instrument use requests from investigators planning electromagnetic surveys via webform submission on its web site ngf.coas.oregonstate.edu. The site is also a port of entry to request access to the 46 long period magnetotelluric instruments also operated by OSU as national instrument pools. Cyberinfrastructure support is available to investigators, including field computers, EM data processing software, and access to a hybrid CPU-GPU parallel computing environment, currently configured with dual Intel Westmere hexacore CPUs and 960 NVidia Tesla and 1792 Nvidia Fermi GPU cores. The capabilities of the Zen/5 receivers will be presented, with examples of data acquired from a recent shallow water marine controlled source experiment conducted in coastal Oregon as part of an effort to locate a buried submarine pipeline, using a 1.1 KW 256 Hz signal source imposed on the pipeline from shore. A Zen/5 prototype instrument, modified for marine use through support by the Oregon Wave Energy Trust, demonstrated the marine capabilities of the NGF instrument design.

  20. Ultra-wideband fiber optical parametric amplifier for spectrally-encoded microscopy (Conference Presentation)

    Science.gov (United States)

    Wei, Xiaoming; Tan, Sisi; Mussot, Arnaud; Kudlinski, Alexandre; Tsia, Kevin K.; Wong, Kenneth

    2016-03-01

    Fiber optical parametric amplifier (FOPA) has gained its popularity in the telecommunication systems at the 1.5-um window for its gain, bandwidth etc. Unfortunately, its practical application at the bio-favorable window, i.e. 1.0 um, still requires substantial efforts. Thus, here we report a versatile all-fiber optical parametric amplifier for life-science (OPALS) at 1.0 um as an add-on module for optical imaging system. The parametric gain fiber (photonic-crystal fiber (PCF), 110 m in length) is specially designed to reduce the longitudinal dispersion fluctuation, which yields a superior figure of merit, i.e. a total insertion loss of ~2.5 dB and a nonlinear coefficient of 34 /(W•km). Our OPALS delivers a superior performance in terms of gain (~158,000), bandwidth (>100 nm) and gain flatness (Experimentally, we show that: 1) a wavelength-varying quasi-monochrome pump achieves a 52-dB gain and 160-nm bandwidth, but at the expense of a larger gain-spectrum ripple, i.e. a bell-shaped; 2) the birefringence of the parametric gain medium, i.e. PCF in this case, can be utilized to improve the gain-spectrum flatness of OPALS by 10.5 dB, meanwhile a 100-nm bandwidth can be guaranteed; 3) the gain-spectrum flatness of OPALS can be further flattened by using a high-speed wavelength-sweeping pump, which exhibits a 110-nm flat gain spectrum with ripple less than 3 dB. Finally, we employ this versatile all-fiber OPALS as an add-on module to enhance the sensitivity of a spectrally-encoded microscope by 47 dB over an ultra-wide spectral range.

  1. Utilizing Symmetry of Planar Ultra-Wideband Antennas for Size Reduction and Enhanced Performance

    CERN Document Server

    Mobashsher, Ahmed Toaha

    2015-01-01

    With the increasingly new ultra wide-band applications, antenna researchers face huge challenges in designing novel operational geometries. Mono-pole and quasi-mono-pole antennas are seen to be the most compact and easily incorporate able solution for portable devices taking the advantages of printed circuit board (PCB) techniques. Most antennas of such type have symmetrical structures. It is possible to attain wider operating bandwidths by meeting symmetry conditions while chopping the antenna into halves for a compact structure. However, there is no generalized way of applying such a technique. The presented paper addresses this issue by proposing a common feeding technique that can be applied to any antenna which is miniaturized using its symmetrical structure. The proposed technique enables feeding the halved structure to achieve wider and better impedance matching than the reported full-size antennas. The theory of characteristic modes is applied to quasi-mono-pole structures to get an insight of the ant...

  2. Design of mid-infrared ultra-wideband metallic absorber based on circuit theory

    Science.gov (United States)

    Arik, Kamalodin; Abdollahramezani, Sajjad; Farajollahi, Saeed; Khavasi, Amin; Rejaei, Behzad

    2016-12-01

    An ultra-broadband absorber of light is proposed by using periodic array of ultra-thin metallic ribbons on top of a lossless quarter-wavelength dielectric spacer placed on a metallic reflector. We propose a fully analytical circuit model for the structure, and then the absorber is duly designed based on the impedance matching concept. As a result, normalized bandwidth of 99.5% is realized by the proposed absorbing structure in mid-infrared regime. Performing a numerical optimization algorithm, we could also reach to normalized bandwidth of 103%.

  3. Low-Cost Ultra-Wideband EM Sensor for UXO Detection and Classification

    Science.gov (United States)

    2012-04-01

    chose to use a MOTU audio signal processing system that ESS already had on hand. This system provides 24 ADC channels and 24 DAC channels, and...processing system with a PC and the MOTU digital audio unit (left). Photograph of the MOTU digital audio unit and signal cables that connect to the...resistance COTS Commercial-Off-The-Shelf DAC Digital to Analog Converter DC Direct Current DSP Digital Signal Processor EM Electromagnetic EMI

  4. Low-Cost Transceiver Architectures for 60 GHz Ultra Wideband WLANs

    Directory of Open Access Journals (Sweden)

    S. O. Tatu

    2009-01-01

    Full Text Available Millimeter-wave multiport transceiver architectures dedicated to 60 GHz UWB short-range communications are proposed in this paper. Multi-port circuits based on 90° hybrid couplers are intensively used for phased antenna array, millimeter-wave modulation and down-conversion, as a low-cost alternative to the conventional architecture. This allows complete integration of circuits including antennas, in planar technology, on the same substrate, improving the overall transceiver performances.

  5. Handbook of ultra-wideband short-range sensing theory, sensors, applications

    CERN Document Server

    Sachs, Jürgen

    2013-01-01

    Ranging from the theoretical basis of UWB sensors via implementation issues to applications, this much-needed book bridges the gap between designers and appliers working in civil engineering, biotechnology, medical engineering, robotic, mechanical engineering, safety and homeland security. From the contents: * History * Signal and systems in time and frequency domain * Propagation of electromagnetic waves (in frequency and time domain) * UWB-Principles * UWB-antennas and applicators * Data processing * Applications

  6. Ultra Wideband (UWB) Synchronous Impulse Reconstruction (SIRE) Radar Upgrade Assessment Field Experiment

    Science.gov (United States)

    2011-04-01

    various orientations : forward- looking at 0°, left and right side-looking at angles of ±45° and ±90°. The RF electronic switch was incorporated to...receive channels housed in a Versa Module Europa (VME) eight-slot, 6U form factor chassis. Four receive channels are located on a single circuit...a) verifying proper placement (location and orientation ) of targets, (b) monitoring GPS surveys, and (c) verifying digital documentation of targets

  7. High-Speed Turbo-TCM-Coded Orthogonal Frequency-Division Multiplexing Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    Wang Yanxia

    2006-01-01

    Full Text Available One of the UWB proposals in the IEEE P802.15 WPAN project is to use a multiband orthogonal frequency-division multiplexing (OFDM system and punctured convolutional codes for UWB channels supporting a data rate up to 480 Mbps. In this paper, we improve the proposed system using turbo TCM with QAM constellation for higher data rate transmission. We construct a punctured parity-concatenated trellis codes, in which a TCM code is used as the inner code and a simple parity-check code is employed as the outer code. The result shows that the system can offer a much higher spectral efficiency, for example, 1.2 Gbps, which is 2.5 times higher than the proposed system. We identify several essential requirements to achieve the high rate transmission, for example, frequency and time diversity and multilevel error protection. Results are confirmed by density evolution.

  8. Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna

    Science.gov (United States)

    duToit, Cornelis

    2014-01-01

    A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA's EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35deg off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array. EcoSAR is an airborne interferometric P-band synthetic aperture radar (SAR) research application for studying two- and three-dimensional fine-scale measurements of terrestrial ecosystem structure and biomass, which will ultimately aid in the broader study of the carbon cycle and climate change. The two 2×8 element Pband antenna arrays required by the system will be separated by a baseline of about 25 m, allowing for interferometry measurements. The wide 100-to- 200-MHz bandwidth dual-polarized beams employed will allow the determination of the amount of biomass and even tree height on the ground. To reduce the size of the patches along the boresight dimension in order to fit them into the available space, two techniques were employed. One technique is to add slots along the edges of each patch where the main electric currents are expected to flow, and the other technique is to bend the central part of the patch away from the ground plane. The latter also facilitates higher mechanical rigidity. The high port isolation of more than 40 dB was achieved by employing a highly symmetrical feed mechanism for each pair of elements: three apertures coupling to the patch elements were placed along the two symmetry lines of the antenna element pair. Two apertures were used in tandem to excite two of the stacked patch elements for one polarization; the other was used to excite one element from one side and the other element from the other side, opposite in phase, taking care of the remaining polarization. The apertures narrow down to a small gap where they are excited by a crossing microstrip line to prevent any asymmetrical excitation of the two sides of the aperture gap, minimizing port-to-port coupling. Using patches that are non-planar leads to higher mechanical rigidity and smaller patch sizes to fit into the available space. Aperture coupling minimizes direct metal-to-metal connections. Using an aperture coupling feed mechanism results in a feed network for two antenna elements with a total of three feed points, plus one simple in-phase combiner to reduce it to two ports. It greatly reduces the complexity of the alternative, but more conventional, way of feeding a pair of two dual-polarized elements with high port isolation.

  9. A novel and simple coplanar waveguide-fed planar monopole antenna for ultra-wideband applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, a novel and simple CPW-fed planar monopole antenna is presented for UWB application. The antenna is fabricated on inexpensive FR4 substrate and fed by 50Ω CPW on the same layer. Measured data show that the antenna provides an impedance bandwidth of about 8GHz for the return loss less than 10dB. It is also observed that the radiation patterns are nearly omni-directional over the entire frequency range. Details of the proposed antenna are presented, and simulated results are presented and discussed.

  10. Low-Power Ultra-Wideband Radio and Radar Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Prime Research LC (PRLC), Virginia Tech (VT), and the University of Texas at Arlington (UTA) propose to develop an ultra-low power radio/radar based on a CMOS...

  11. Ultra-Wideband Radar for Breath Tracking with Optical Fiber for Remote Reach Extension

    DEFF Research Database (Denmark)

    Suhr, Lau Frejstrup; Tafur Monroy, Idelfonso; Vegas Olmos, Juan José

    2016-01-01

    We report on the experimental demonstration of an UWB radar with fiber extension for remote breath tracking through 10 cm of concrete. The radar is based on telecom class equipment.......We report on the experimental demonstration of an UWB radar with fiber extension for remote breath tracking through 10 cm of concrete. The radar is based on telecom class equipment....

  12. Short-Range Ultra-Wideband Imaging with Multiple-Input Multiple-Output Arrays

    NARCIS (Netherlands)

    Zhuge, X.

    2010-01-01

    Compact, cost-efficient and high-resolution imaging sensors are especially desirable in the field of short-range observation and surveillance. Such sensors are of great value in fields of security, rescue and medical applications. Systems can be formed for various practical purposes, such as

  13. Time Modulated Arrays: From their Origin to Their Utilization in Wireless Communication Systems

    Directory of Open Access Journals (Sweden)

    Roberto Maneiro-Catoira

    2017-03-01

    Full Text Available Time-modulated arrays (TMAs are electromagnetic systems whose radiated power pattern is controlled by the application of variable-width periodical pulses to the individual elements. The nonlinear nature of the array operation causes the appearance of radiation patterns at the harmonic frequencies of such periodic pulses. The technique can be used for improving the side-lobe level (SLL topology of the radiation pattern at the central frequency and/or to profitably exploit the harmonic patterns in order to supply smart antenna capabilities. Among the latter features, the TMA harmonic beamforming takes on special importance due to its attractive trade-off performance-hardware complexity. From this perspective, TMAs are sensors capable of transforming the spatial diversity of a communication channel into frequency diversity, thus improving the performance of a wireless communication. In addition to a walk through the origins of the concept, and a brief analysis of the mathematical fundamentals, this paper organizes the prolific state of the art of TMAs in two major thematic blocks: (1 TMA design from an antenna perspective; and (2 TMA design from a signal processing perspective.

  14. Primary sleep enuresis in childhood: polysomnography evidences of sleep stage and time modulation

    Directory of Open Access Journals (Sweden)

    Rubens Reimäo

    1993-03-01

    Full Text Available The objective of this study was to evaluate enuretic events and its relations to sleep stages, sleep cycles and time durations in a selected group of children with primary essential sleep enuresis. We evaluated 18 patients with mean age of 8.2 years old (ranging from 5 to 12 years; 10 were males and 8 females (n.s.. They were referred to the Sleep Disorders Center with the specific complaint of enuresis since the first years of life (primary. Pediatric, urologic and neurologic workup did not show objective abnormalities (essential. The standard all-night polysomnography including an enuresis sensor attached to the shorts in the crotch area was performed. Only enuretic events nights were included. All were drug free patients for two weeks prior to polysomnography. In this report, only one polysomnography per patient was considered. The enuretic events were phase related, occurring predominantly in non-REM (NREM sleep (p<0.05. There was no predominance of enuretic events among the NREM stages (n.s.. A tendency of these events to occur in the first two sleep cycles was detected but may be due to the longer duration of these cycles. The events were time modulated, adjusted to a normal distribution with a mean of 213.4 min of recording time.

  15. Time Modulated Arrays: From their Origin to Their Utilization in Wireless Communication Systems

    Science.gov (United States)

    Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis

    2017-01-01

    Time-modulated arrays (TMAs) are electromagnetic systems whose radiated power pattern is controlled by the application of variable-width periodical pulses to the individual elements. The nonlinear nature of the array operation causes the appearance of radiation patterns at the harmonic frequencies of such periodic pulses. The technique can be used for improving the side-lobe level (SLL) topology of the radiation pattern at the central frequency and/or to profitably exploit the harmonic patterns in order to supply smart antenna capabilities. Among the latter features, the TMA harmonic beamforming takes on special importance due to its attractive trade-off performance-hardware complexity. From this perspective, TMAs are sensors capable of transforming the spatial diversity of a communication channel into frequency diversity, thus improving the performance of a wireless communication. In addition to a walk through the origins of the concept, and a brief analysis of the mathematical fundamentals, this paper organizes the prolific state of the art of TMAs in two major thematic blocks: (1) TMA design from an antenna perspective; and (2) TMA design from a signal processing perspective. PMID:28335415

  16. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    Science.gov (United States)

    Balvert, Marleen; Gorissen, Bram L.; den Hertog, Dick; Hoffmann, Aswin L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2-5 cc. However, this comes at a cost of a reduction in D90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D90% against uncertainty in dwell positions for both models.

  17. Engineer Calvin H. Seaman demonstrates STS-49 INTELSAT capture bar at JSC

    Science.gov (United States)

    1992-01-01

    Project Engineer Calvin H. Seaman (center) briefs news media representatives on the grapple fixture (capture bar) expected to be instrumental in the capture of the International Telecommunications Satellite Organization (INTELSAT) VI satellite in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9. Seaman is a JSC engineer who designed the capture bar. After Endeavour, Orbiter Vehicle (OV) 105, is maneuvered into a tight proximity operations configuration with the errant satellite, two STS-49 crewmembers will attach the grapple device to the aft side of INTELSAT, as demonstrated with this full-scale mockup. The communications satellite will then be mated with a perigee stage, which the crewmembers will carry with them on their May launch, and released into space. Its motor will be fired many hours afterward, sending it on its way to a higher, geosynchronous orbit. The Errant Satellite Simulator is set up on the Air Bearing Floor for the demonstration. Photo taken by NASA JSC contract

  18. MODERN RESOURCE-SAVING TECHNOLOGIES IN FOUNDRY PRODUCTION OF JSC «MINSK TRAKTOR PLANT»

    Directory of Open Access Journals (Sweden)

    F. A. Domotenko

    2016-01-01

    Full Text Available In article the main world tendencies of development of the production technology of sandy cores and value of this production in complex technology of manufacture of castings are considered. It is established that the most rational way of production technically and economically is manufacture of wafer sandy cores using the Cold-box-amin technology. Scientific, technical, technological and economic aspects of modernization of foundry production of JSC MTZ with complete transition to production of sandy cores on the resource-saving Cold-box-amin technology are provided. The main distinctive feature of this reequipment – all planned works are based on the domestic technological developments and the equipment created in the cooperation by specialists of JSC BELNIILIT and JSC MTZ. Within GNTP essential support to the provided works was given by the state.

  19. Improvement of Operational Reliability Resource for JSC “Beltransgaz” Main Pipelines

    Directory of Open Access Journals (Sweden)

    V. Mayorov

    2013-01-01

    Full Text Available  The paper considers prospects for modernization of the operating linear portion of JSC “Beltransgaz” gas transportation system, various methods and materials which are used while implementing  construction and installation works in the oil and gas sector. It has been shown that in the recent decade one of the most technically, technologically and economically efficient application of the material is double-composite polyurethane coating. The method for coating deposition has been tested and introduced by JSC “Beltransgaz” with significant economic efficiency.

  20. ASTP crewmen in Apollo Command Module Trainer during training session at JSC

    Science.gov (United States)

    1975-01-01

    The three members of the American ASTP prime crew are photographed inside the Apollo Command Module (CM) trainer in a water tank in bldg 260 during water egress training at JSC. They are, left to right, Astronauts Thomas P. Stafford, commander; Vance D. Brand, command module pilot; and Donald K. Slayton, docking module pilot (23430); Slayton attaches his life preserver as he egresses an Apollo Command Module trainer in a water tank in bldg 260 during water egresss training at JSC. Astronauts Brand (on left) and Stafford have already egressed the trainer and are seated in a three-man life raft.

  1. STS-31 crewmembers during simulation on the flight deck of JSC's FB-SMS

    Science.gov (United States)

    1988-01-01

    On the flight deck of JSC's fixed based (FB) shuttle mission simulator (SMS), Mission Specialist (MS) Steven A. Hawley (left), on aft flight deck, looks over the shoulders of Commander Loren J. Shriver, seated at the commanders station (left) and Pilot Charles F. Bolden, seated at the pilots station and partially blocked by the seat's headrest (right). The three astronauts recently named to the STS-31 mission aboard Discovery, Orbiter Vehicle (OV) 103, go through a procedures checkout in the FB-SMS. The training simulation took place in JSC's Mission Simulation and Training Facility Bldg 5.

  2. Organic Contamination Baseline Study: In NASA JSC Astromaterials Curation Laboratories. Summary Report

    Science.gov (United States)

    Calaway, Michael J.

    2013-01-01

    In preparation for OSIRIS-REx and other future sample return missions concerned with analyzing organics, we conducted an Organic Contamination Baseline Study for JSC Curation Labsoratories in FY12. For FY12 testing, organic baseline study focused only on molecular organic contamination in JSC curation gloveboxes: presumably future collections (i.e. Lunar, Mars, asteroid missions) would use isolation containment systems over only cleanrooms for primary sample storage. This decision was made due to limit historical data on curation gloveboxes, limited IR&D funds and Genesis routinely monitors organics in their ISO class 4 cleanrooms.

  3. 77 FR 31794 - Financial Crimes Enforcement Network; Imposition of Special Measure Against JSC CredexBank as a...

    Science.gov (United States)

    2012-05-30

    ... Against JSC CredexBank as a Financial Institution of Primary Money Laundering Concern AGENCY: Financial... that JSC CredexBank is a financial institution of primary money laundering concern pursuant to 31 U.S.C...), Public Law 107-56. Title III of the USA PATRIOT Act amends the anti- money laundering provisions of...

  4. STS-46 MS Chang-Diaz floats in life raft during water egress training at JSC

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Franklin R. Chang-Diaz, wearing launch and entry suit (LES) and launch and entry helmet (LEH), relies on a one-person life raft to get him to 'safety' during a launch emergency egress (bailout) simulation conducted in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

  5. STS-35 Pilot Gardner shoots picture during water egress training at JSC

    Science.gov (United States)

    1990-01-01

    STS-35 Pilot Guy S. Gardner shoots picture using a 35mm camera during water egress training conducted in the Weightless Environment Training Facility (WETF) Bldg 29 at JSC. Gardner is wearing a launch and entry suit and a life jacket.

  6. STS-56 Commander Cameron, in LES, during JSC emergency egress training

    Science.gov (United States)

    1992-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron, wearing launch and entry suit (LES), poses at the Crew Compartment Trainer (CCT) side hatch before climbing into the mockup. Cameron, along with the other STS-56 crewmembers, is participating in an emergency egress simulation at JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  7. STS-37 Pilot Kenneth D. Cameron during egress training in JSC's WETF Bldg 29

    Science.gov (United States)

    1990-01-01

    STS-37 Pilot Kenneth D. Cameron, wearing launch and entry suit (LES), discusses simulated emergency egress training on the pool side of JSC's Weightless Environment Training Facility (WETF) Bldg 29. Cameron will be dropped into a simulated ocean, the WETF's 25-ft pool, into which a parachute landing might be made.

  8. STS-37 Mission Specialist (MS) Godwin during simulation in JSC's FB-SMS

    Science.gov (United States)

    1991-01-01

    STS-37 Mission Specialist (MS) Linda M. Godwin rehearses some phases of her scheduled duties on the middeck of the fixed-based (FB) shuttle mission simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. Godwin is inspecting supplies stowed in the middeck lockers during this unsuited simulation.

  9. STS-37 Mission Specialist (MS) Ross during simulation in JSC's FB-SMS

    Science.gov (United States)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross 'borrows' the pilots station to rehearse some of his scheduled duties for his upcoming mission. He is on the flight deck of the fixed-based (FB) shuttle mission simulator (SMS) during this unsuited simulation. The SMS is part of JSC's Mission Simulation and Training Facility Bldg 5.

  10. STS-44 Atlantis, OV-104, MS Musgrave on FB-SMS middeck during JSC training

    Science.gov (United States)

    1991-01-01

    STS-44 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) F. Story Musgrave, wearing lightweight headset (HDST), adjusts controls on communications module mounted on a middeck overhead panel. Musgrave is on the middeck of the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. The STS-44 crewmembers are participating in a flight simulation.

  11. STS-31 Pilot Bolden with beverages on the FB-SMS middeck during JSC training

    Science.gov (United States)

    1988-01-01

    STS-31 Pilot Charles F. Bolden holds three beverage containers while in front of the galley on the middeck of the fixed based (FB) shuttle mission simulator (SMS) during a training simulation at JSC's Mission Simulation and Training Facility Bldg 5. From the middeck, Bolden, wearing lightweight headset, simulates a communications link with ground controllers and fellow crewmembers.

  12. STS-31 crewmembers review checklist with instructor on JSC's FB-SMS middeck

    Science.gov (United States)

    1988-01-01

    STS-31 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Bruce McCandless II (left) and Pilot Charles F. Bolden (right) discuss procedures with a training instructor on the middeck of JSC's fixed-based (FB) Shuttle Mission Simulator (SMS). The three are pointing to a checklist during this training simulation in the Mission Simulation and Training Facility Bldg 5.

  13. STS-44 Atlantis, OV-104, Pilot Henricks in FB-SMS training at JSC

    Science.gov (United States)

    1991-01-01

    STS-44 Atlantis, Orbiter Vehicle (OV) 104, Pilot Terence T. Henricks, seated at the pilots station on the forward flight deck, reviews checklists before a flight simulation in the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. Surrounding Henricks are the seat back, the overhead panels, forward panels, and forward windows.

  14. STS-32 MS Dunbar trains in JSC Manipulator Development Facility (MDF)

    Science.gov (United States)

    1989-01-01

    STS-32 Mission Specialist (MS) Bonnie J. Dunbar reviews checklist with training personnel in the Manipulator Development Facility (MDF) in JSC's Mockup and Integration Facility (MAIL) Bldg 9A. Dunbar (left) discusses procedures with trainer in front of the aft flight deck onorbit station controls. Overhead window W8 is visible above their heads.

  15. Technicians assist STS-47 MS Jemison prior to JSC bailout training

    Science.gov (United States)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) Mae C. Jemison, assisted by technicians, adjusts a strap on her launch and entry suit (LES) prior to launch emergency egress (bailout) exercises in JSC's Mockup and Integration Laboratory Bldg 9A. Jemison is making her first flight in space.

  16. Spacelab Life Sciences (SLS) echocardiograph in mockup rack in JSC's Bldg 36

    Science.gov (United States)

    1987-01-01

    Spacelab Life Sciences (SLS) life sciences laboratory equipment (LSLE) echocardiograph is documented in the JSC Bioengineering and Test Support Facility Bldg 36. Displayed on the echocardiograph monitor is a heart image. The echocardiograph equipment is located in Rack 6 and will be used in conjunction with Experiment No. 294 Cardiovascular Adaptation to Zero Gravity during the STS-40 SLS-1 mission.

  17. STS-46 Payload Specialist Malerba sits at the pilots station in JSC mockup

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Italian Payload Specialist Franco Malerba sits at the pilots station on the forward flight deck of the Full Fuselage Trainer (FFT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9. Malerba, wearing a flight suit, is participating in a hardware familiarity training session.

  18. STS-41 MS Akers looks up at mockup prior to egress training in JSC's MAIL

    Science.gov (United States)

    1990-01-01

    STS-41 Mission Specialist (MS) Thomas D. Akers, wearing launch and entry suit (LES), looks up at crew compartment trainer (CCT) prior to emergency egress training exercises. The exercises were conducted in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A.

  19. STS-28 Columbia, OV-102, MS Brown dons LES in JSC Mockup and Integration Lab

    Science.gov (United States)

    1989-01-01

    STS-28 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist (MS) Mark N. Brown, wearing communications carrier assembly (CCA) and launch and entry suit (LES), prepares to don launch and entry helmet (LEH). Brown suits up for shuttle emergency egress (bailout) procedures in JSC Mockup and Integration Laboratory Bldg 9A.

  20. STS-46 MS Chang-Diaz floats in life raft during water egress training at JSC

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Franklin R. Chang-Diaz, wearing launch and entry suit (LES) and launch and entry helmet (LEH), relies on a one-person life raft to get him to 'safety' during a launch emergency egress (bailout) simulation conducted in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

  1. The 2015-2016 SEPMAP Program at NASA JSC: Science, Engineering, and Program Management Training

    Science.gov (United States)

    Graham, L.; Archer, D.; Bakalyar, J.; Berger, E.; Blome, E.; Brown, R.; Cox, S.; Curiel, P.; Eid, R.; Eppler, D.; Fries, M.; Gruener, J.; Haddock, M.; Harder, K.; Hong, T.; McCann, C.; Neiss, K.; Newswander, J.; Odina, J.; Peslier, A.; Quadri, Z.; Ross, S.; Rutovic, M.; Schulte, R.; Thomas, R.; Vos, J.; Waid, M.; William, B.

    2017-01-01

    The Systems Engineering Project Management Advancement Program (SEPMAP) at NASA Johnson Space Center (JSC) is an employee development program designed to provide graduate level training in project management and systems engineering. The program includes an applied learning project with engineering and integrated science goals requirements. The teams were presented with a task: Collect a representative sample set from a field site using a hexacopter platform, as if performing a scientific reconnaissance to assess whether the site is of sufficient scientific interest to justify exploration by astronauts. Four teams worked through the eighteen-month course to design customized sampling payloads integrated with the hexacopter, and then operate the aircraft to meet sampling requirements of number (= 5) and mass (= 5g each). The "Mars Yard" at JSC was utilized for this purpose. This project activity closely parallels NASA plans for the future exploration of Mars, where remote sites will be reconnoitered ahead of crewed exploration.

  2. STS-56 Commander Cameron, in LES, with sky genie during JSC egress training

    Science.gov (United States)

    1992-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron, wearing launch and entry suit (LES), gives the sky-genie escape device a tug as training instructor Kenneth D. Trujillo holds it in position and explains its operation. Cameron, along with the other STS-56 crewmembers, is briefed on emergency egress procedures at JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE prior to a training simulation. The sky-genie is carried on all Space Shuttle flights for emergency egress purposes.

  3. STS-56 Commander Cameron and Pilot Oswald at CCT hatch during JSC training

    Science.gov (United States)

    1993-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron (right) and Pilot Stephen S. Oswald, wearing launch and entry suits (LESs), stand at the side hatch of the crew compartment trainer (CCT), a shuttle mockup, prior to entering the mockup. Once inside the CCT, they will don their launch and entry helmets (LEHs) and participate in emergency egress (bailout) procedures. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  4. ASTP crewmen in Docking Module trainer during training session at JSC

    Science.gov (United States)

    1975-01-01

    An interior view of the Docking Module trainer in bldg 35 during Apollo Soyuz Test Project (ASTP) joint crew training at JSC. Astronaut Donald K. Slayton (right) is the docking module pilot of the American ASTP prime crew. The other man is Cosmonaut Valeriy N. Kubasov, engineer on the Soviet ASTP first (prime) crew. The training session simulated activities on the second day in space. The Docking module is designed to link the Apollo and Soyuz spacecraft.

  5. STS-37 crewmembers train in JSC's FB shuttle mission simulator (SMS)

    Science.gov (United States)

    1991-01-01

    STS-37 Commander Steven R. Nagel (left) and Mission Specialist (MS) Jerry L. Ross rehearse some of their scheduled duties on the flight deck of JSC's fixed-based (FB) shuttle mission simulator (SMS) located in the Mission Simulation and Training Facility Bldg 5. During the unsuited simulation, Nagel reviews checklist while seated at the commanders station as Ross looks on from the pilots station.

  6. STS-36 crewmembers train in JSC's FB shuttle mission simulator (SMS)

    Science.gov (United States)

    1989-01-01

    STS-36 Mission Specialist (MS) David C. Hilmers, seated on the aft flight deck, discusses procedures with Commander John O. Creighton (left) and Pilot John H. Casper during a simulation in JSC's Fixed Based (FB) Shuttle Mission Simulator (SMS). Casper reviews a checklist at the pilots station on the forward flight deck. The crewmembers are rehearsing crew cabin activities for their upcoming Department of Defense (DOD) mission aboard Atlantis, Orbiter Vehicle (OV) 104.

  7. STS-44 Atlantis, OV-104, crewmembers participate in JSC FB-SMS training

    Science.gov (United States)

    1991-01-01

    STS-44 Atlantis, Orbiter Vehicle (OV) 104, Commander Frederick D. Gregory and Pilot Terence T. Henricks are stationed at their appointed positions on the forward flight deck of the Fixed Base (FB) Shuttle Mission Simulator (SMS) in JSC's Mission Simulation and Training Facility Bldg 5. Gregory (left) in the commanders seat and Henricks (right) in the pilots seat look back toward aft flight deck and the photographer. Seat backs appear in the foreground and forward flight deck control panels in the background.

  8. STS-44 Atlantis, OV-104, crewmembers participate in FB-SMS training at JSC

    Science.gov (United States)

    1991-01-01

    STS-44 Atlantis, Orbiter Vehicle (OV) 104, Commander Frederick D. Gregory (left) and Pilot Terence T. Henricks, positioned at their appointed stations on the forward flight deck, are joined by Mission Specialist (MS) F. Story Musgrave (center) and MS James S. Voss (standing). The crewmembers are participating in a flight simulation in the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. A maze of panel switches appear overhead and in the background.

  9. STS-49 crew in JSC's FB Shuttle Mission Simulator (SMS) during simulation

    Science.gov (United States)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, crewmembers participate in a simulation in JSC's Fixed Base (FB) Shuttle Mission Simulator (SMS) located in the Mission Simulation and Training Facility Bldg 5. Wearing launch and entry suits (LESs) and launch and entry helmets (LEH) and seated on the FB-SMS middeck are (left to right) Mission Specialist (MS) Thomas D. Akers, MS Kathryn C. Thornton, and MS Pierre J. Thuot.

  10. STS-46 crewmembers participate in Fixed Base (FB) SMS training at JSC

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Pilot Andrew M. Allen hands Mission Specialist (MS) and Payload Commander (PLC) Jeffrey A. Hoffman checklists from middeck locker MF43E during training session in JSC's fixed base (FB) shuttle mission simulator (SMS) located in Mission Simulation and Training Facility Bldg 5. European Space Agency (ESA) MS Claude Nicollier outfitted with communications kit assembly headset (HDST) and equipment looks beyond Hoffman to the opposite side of the middeck.

  11. STS-38 Mission Specialist (MS) Robert C. Springer dons EMU in JSC's WETF

    Science.gov (United States)

    1990-01-01

    STS-38 Mission Specialist (MS) Robert C. Springer, wearing extravehicular mobility unit (EMU), fastens the strap on his communications carrier assembly (CCA) cap during suit donning in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Positioned on the WETF platform at pool side, Springer is preparing for an underwater extravehicular activity (EVA) simulation. During the training exercise, Springer will rehearse contingency EVA procedures for the STS-38 mission aboard Atlantis, Orbiter Vehicle (OV) 104.

  12. STS-38 Mission Specialist (MS) Robert C. Springer dons EMU in JSC's WETF

    Science.gov (United States)

    1990-01-01

    STS-38 Mission Specialist (MS) Robert C. Springer dons extravehicular mobility unit (EMU) upper torso with technicians' assistance in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Positioned on the WETF platform at pool side, Springer is preparing for an underwater extravehicular activity (EVA) simulation. During the training session, Springer will rehearse contingency EVA procedures for the STS-38 mission aboard Atlantis, Orbiter Vehicle (OV) 104.

  13. STS-34 crewmembers train with the IMAX camera in JSC's Bldg 9B mockup area

    Science.gov (United States)

    1989-01-01

    STS-34 crewmembers participate in IMAX camera training session held in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9B. The crew is briefed on the operation and handling of the IMAX camera scheduled to fly aboard Atlantis, Orbiter Vehicle (OV) 104. Standing behind the IMAX camera is Mission Specialist (MS) Franklin R. Chang-Diaz with IMAX instructors Grant Ferguson and David Douglas on his left. Commander Donald E. Williams (looking at IMAX lens) is at the right edge of the photo.

  14. Technicians complete assembly of Hubble Space Telescope (HST) mockup at JSC

    Science.gov (United States)

    1989-01-01

    A technician listens to instructions as he operates the controls for the overhead crane that is lifting one of the Hubble Space Telescope (HST) high gain antennas (HGAs) into place on the HST Support System Module (SSM) forward shell. Others in a cherry picker basket wait to install the HGA on the SSM mockup. The HST mockup will be used for astronaut training and is being assembled in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A.

  15. STS-29 crewmembers launch/landing procedural training in JSC mockup

    Science.gov (United States)

    1986-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, Pilot John E. Blaha and Mission Specialist (MS) Robert C. Springer participate in launch and landing training on JSC mockup flight deck in the Mockup and Integration Laboratory Bldg 9A. Blaha sits at the pilots station controls in front of Springer who is seated on aft flight deck in mission specialist seat. Springer prepares to don communications kit assembly headset.

  16. STS-40 Payload Specialist Millie Hughes-Fulford trains in JSC's SLS mockup

    Science.gov (United States)

    1987-01-01

    STS-40 Payload Specialist Millie Hughes-Fulford conducts Spacelab Life Sciences 1 (SLS-1) Experiment No. 198, Pulmonary Function During Weightlessness, in JSC's Life Sciences Project Division (LSPD) SLS mockup located in the Bioengineering and Test Support Facility Bldg 36. Hughes-Fulford monitors instruments and settings on Rack 8's panels. Behind her in the center aisle are the body mass measurement device (foreground) and the stowed bicycle ergometer.

  17. STS-26 Pilot Covey, wearing launch and entry suit, trains in JSC mockup area

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing the orange launch and entry suit (LES) and launch and entry helmet (LEH), pauses during a training exercise in JSC Mockup and Integration Laboratory Bldg 9A crew compartment trainer (CCT). LES, a partial pressure suit to be worn during launch and entry phases of the space shuttle flight, was evaluated and checked out.

  18. STS-34 crewmembers review IFM procedures on JSC's CCT mockup middeck

    Science.gov (United States)

    1989-01-01

    STS-34 crewmembers review inflight maintenance (IFM) procedures on the middeck of JSC's crew compartment trainer (CCT) located in the Mockup and Integration Laboratory (MAIL) Bldg 9A. IFM trainer, holding cable, discusses procedures with Mission Specialist (MS) Ellen S. Baker (center) and Pilot Michael J. McCulley. An open stowage locker appears in front of the group. Visible on the mockup's middeck are forward and aft stowage lockers, the airlock hatch, and the starboard wall mounted sleep restraints.

  19. STS-26 MS Nelson during training exercise in JSC Mockup and Integration Lab

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson, wearing navy blue launch and entry suit (LES) and launch and entry helmet (LEH), is seated in his launch and entry position on crew compartment trainer (CCT) middeck during a training exercise in JSC Mockup and Integration Laboratory Bldg 9A. Visible in the background are the airlock, stowed treadmill, and sleep restraints. NOTE: Photo was taken by William H. Bowers, crew photo instructor, with wide angle lens.

  20. STS-46 Payload Specialist Malerba at aft flight deck controls in JSC mockup

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Italian Payload Specialist Franco Malerba, wearing flight suit, operates controls on the aft flight deck of the Full Fuselage Trainer (FFT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9. During the training session, Malerba adjusts a control on the A3 panel closed circuit television (CCTV). Onorbit station panels appear in front of Malerba and payload station controls behind him.

  1. STS-26 crewmembers, wearing launch and entry suits, train in JSC mockup area

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck (left) and Pilot Richard O. Covey, wearing the orange launch and entry suits (LESs), discuss training exercise with technicians in JSC Mockup and Integration Laboratory Bldg 9A. During the exercise, the LES, a partial pressure suit to be worn during launch and entry phases of the space shuttle flight, was evaluated and checked out.

  2. STS-28 Columbia, OV-102, crewmembers train in JSC Mockup and Integration Lab

    Science.gov (United States)

    1989-01-01

    STS-28 Columbia, Orbiter Vehicle (OV) 102, crewmembers participate in shuttle emergency egress (bailout) procedures in JSC Mockup and Integration Laboratory Bldg 9A. Wearing orange launch and entry suits (LESs), crewmembers (left to right) Mission Specialist (MS) Mark C. Brown, MS David C. Leestma, MS James C. Adamson, Pilot Richard N. Richards, and Commander Brewster H. Shaw pause before training exercise. In the background are training personnel and the Manipulator Development Facility (MDF) surrounded by helium-filled mockups.

  3. STS-26 Commander Hauck, wearing launch and entry suit, trains in JSC mockup

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing the orange launch and entry suit (LES) and launch and entry helmet (LEH), gets assistance from a suit technician prior to participating in a training exercise in JSC Mockup and Integration Laboratory Bldg 9A crew compartment trainer (CCT). During the exercise, the LES, a partial pressure suit to be worn during launch and entry phases of the space shuttle flight, was evaluated and checked out.

  4. ESA MS Nicollier extends mockup tetherline prior to JSC WETF simulation

    Science.gov (United States)

    1987-01-01

    European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier, turning a crank, extends a tetherline from a reel mounted on a mockup of the forward payload bay (PLB) bulkhead. Nicollier familiarizes himself with the operation of the safety tether system prior to donning an extravehicular mobility unit (EMU) and participating in an underwater extravehicular activity (EVA) simu- lation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

  5. STS-47 MS Jemison extends side hatch mockup CES pole during JSC training

    Science.gov (United States)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) Mae C. Jemison extends crew escape system (CES) pole through a side hatch mockup during launch emergency egress (bailout) training in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. MS Jerome Apt (right) looks on. The crewmembers practiced extending the CES pole prior to donning their launch and entry suits (LESs) and conducting the simulation in the Crew Compartment Trainer (CCT).

  6. At JSC's MCC, CAPCOMs display score cards rating STS-26 Discovery landing

    Science.gov (United States)

    1988-01-01

    In JSC's Mission Control Center (MCC) Bldg 30, astronauts and spacecraft communicators (CAPCOMs) L. Blaine Hammond, Jr, John O. Creighton, Frank L. Culbertson, Jr, and an unidentified man display score cards rating the STS-26 Discovery, Orbiter Vehicle (OV) 103, landing at Edwards Air Force Base(EAFB), California. Flight control room (FCR) front visual displays show world tracking map, EAFB post landing activity, and head alignment cone (HAC).

  7. STS-48 MS Gemar uses laptop during training session in JSC's MB SMS

    Science.gov (United States)

    1991-01-01

    STS-48 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Charles D. Gemar, wearing lightweight headset, enters data into a portable laptop computer on the middeck of JSC's Motion Based (MB) Shuttle Mission Simulator (SMS). Gemar is participating in a preflight familiarization session in the MB-SMS located in the Mission Simulation and Training Facility Bldg 5. Visible to Gemar's right is a stowed extravehicular mobility unit (EMU) and on his left are forward locker mockups.

  8. Characterization and Glass Formation of JSC-1 Lunar and Martian Soil Simulants

    Science.gov (United States)

    Sen, Subhayu

    2008-01-01

    The space exploration mission of NASA requires long duration presence of human being beyond the low earth orbit (LEO), especially on Moon and Mars. Developing a human habitat or colony on these planets would require a diverse range of materials, whose applications would range from structural foundations, (human) life support, (electric) power generation to components for scientific instrumentation. A reasonable and cost-effective approach for fabricating the materials needed for establishing a self-sufficient human outpost would be to primarily use local (in situ) resources on these planets. Since ancient times, glass and ceramics have been playing a vital role on human civilization. A long term project on studying the feasibility of developing glass and ceramic materials using Lunar and Martian soil simulants (JSC-1) as developed by Johnson Space Center has been undertaken. The first step in this on-going project requires developing a data base on results that fully characterize the simulants to be used for further investigations. The present paper reports characterization data of both JSC-1 Lunar and JSC Mars-1 simulants obtained up to this time via x-ray diffraction analysis, scanning electron microscopy, thermal analysis (DTA, TGA) and chemical analysis. The critical cooling rate for glass formation for the melts of the simulants was also measured in order to quantitatively assess the glass forming tendency of these melts. The importance of the glasses and ceramics developed using in-situ resources for constructing human habitats on Moon or Mars is discussed.

  9. Gas Phase Pressure Effects on the Apparent Thermal Conductivity of JSC-1A Lunar Regolith Simulant

    Science.gov (United States)

    Yuan, Zeng-Guang; Kleinhenz, Julie E.

    2011-01-01

    Gas phase pressure effects on the apparent thermal conductivity of a JSC-1A/air mixture have been experimentally investigated under steady state thermal conditions from 10 kPa to 100 kPa. The result showed that apparent thermal conductivity of the JSC-1A/air mixture decreased when pressure was lowered to 80 kPa. At 10 kPa, the conductivity decreased to 0.145 W/m/degree C, which is significantly lower than 0.196 W/m/degree C at 100 kPa. This finding is consistent with the results of previous researchers. The reduction of the apparent thermal conductivity at low pressures is ascribed to the Knudsen effect. Since the characteristic length of the void space in bulk JSC-1A varies over a wide range, both the Knudsen regime and continuum regime can coexist in the pore space. The volume ratio of the two regimes varies with pressure. Thus, as gas pressure decreases, the gas volume controlled by Knudsen regime increases. Under Knudsen regime the resistance to the heat flow is higher than that in the continuum regime, resulting in the observed pressure dependency of the apparent thermal conductivity.

  10. Development and Validation of a Model for Hydrogen Reduction of JSC-1A

    Science.gov (United States)

    Hegde, U.; Balasubramaniam, R.; Gokoglu, S.

    2009-01-01

    Hydrogen reduction of lunar regolith has been proposed as a viable technology for oxygen production on the moon. Hydrogen reduces FeO present in the lunar regolith to form metallic iron and water. The water may be electrolyzed to recycle the hydrogen and produce oxygen. Depending upon the regolith composition, FeO may be bound to TiO2 as ilmenite or it may be dispersed in glassy substrates. Some testing of hydrogen reduction has been conducted with Apollo-returned lunar regolith samples. However, due to the restricted amount of lunar material available for testing, detailed understanding and modeling of the reduction process in regolith have not yet been developed. As a step in this direction, hydrogen reduction studies have been carried out in more detail with lunar regolith simulants such as JSC-1A by NASA and other organizations. While JSC-1A has some similarities with lunar regolith, it does not duplicate the wide variety of regolith types on the moon, for example, it contains almost no ilmenite. Nonetheless, it is a good starting point for developing an understanding of the hydrogen reduction process with regolith-like material. In this paper, a model utilizing a shrinking core formulation coupled with the reactor flow is described and validated against experimental data on hydrogen reduction of JSC-1A.

  11. Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber-A

    Science.gov (United States)

    Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

    2013-01-01

    NASA's Space Environment Simulation Laboratory's (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN2) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN2 cooling with centrifugal pumps, requiring 200,000 liters of LN2 to cool-down and consuming 180,000 liters per day of LN2 in steady operation. The LN2 system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the sub-contractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC's request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 70,000 liters to cool-down and less than 90,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

  12. Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber A

    Science.gov (United States)

    Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

    2013-01-01

    NASA s Space Environment Simulation Laboratory s (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN cooling with centrifugal pumps, requiring 220,000 liters of LN to cool-down and consuming 180,000 liters per day of LN in steady operation. The LN system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the subcontractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC s request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 68,000 liters to cool-down and less than 91,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

  13. Coordinated Analysis 101: A Joint Training Session Sponsored by LPI and ARES/JSC

    Science.gov (United States)

    Draper, D. S.; Treiman, A. H.

    2017-01-01

    The Lunar and Planetary Institute (LPI) and the Astromaterials Research and Exploration Science (ARES) Division, part of the Exploration Integration and Science Directorate at NASA Johnson Space Center (JSC), co-sponsored a training session in November 2016 for four early-career scientists in the techniques of coordinated analysis. Coordinated analysis refers to the approach of systematically performing high-resolution and -precision analytical studies on astromaterials, particularly the very small particles typical of recent and near-future sample return missions such as Stardust, Hayabusa, Hayabusa2, and OSIRIS-REx. A series of successive analytical steps is chosen to be performed on the same particle, as opposed to separate subsections of a sample, in such a way that the initial steps do not compromise the results from later steps in the sequence. The data from the entire series can then be integrated for these individual specimens, revealing important in-sights obtainable no other way. ARES/JSC scientists have played a leading role in the development and application of this approach for many years. Because the coming years will bring new sample collections from these and other planned NASA and international exploration missions, it is timely to begin disseminating specialized techniques for the study of small and precious astromaterial samples. As part of the Cooperative Agreement between NASA and the LPI, this training workshop was intended as the first in a series of similar training exercises that the two organizations will jointly sponsor in the coming years. These workshops will span the range of analytical capabilities and sample types available at ARES/JSC in the Astromaterials Research and Astro-materials Acquisition and Curation Offices. Here we summarize the activities and participants in this initial training.

  14. Configuration Management (CM) Support for KM Processes at NASA/Johnson Space Center (JSC)

    Science.gov (United States)

    Cioletti, Louis

    2010-01-01

    Collection and processing of information are critical aspects of every business activity from raw data to information to an executable decision. Configuration Management (CM) supports KM practices through its automated business practices and its integrated operations within the organization. This presentation delivers an overview of JSC/Space Life Sciences Directorate (SLSD) and its methods to encourage innovation through collaboration and participation. Specifically, this presentation will illustrate how SLSD CM creates an embedded KM activity with an established IT platform to control and update baselines, requirements, documents, schedules, budgets, while tracking changes essentially managing critical knowledge elements.

  15. STS-35 Pilot Gardner during fire fighting exercises at JSC fire training pit

    Science.gov (United States)

    1990-01-01

    STS-35 Pilot Guy S. Gardner extinguishes a small blaze during a fire handling training session for crewmembers at JSC Fire Training Pit across from the Gilruth Center Bldg 207. Wearing a navy blue flight suit, Gardner approaches fire while operating a fire extinguisher as Commander Vance D. Brand (far right) and Payload Specialist Samuel T. Durrance look on. The crew was briefed on types of potential blazes and the correct means of controlling each type. STS-35 will mark the first seven-member crew staffing since the Challenger accident of January 1986.

  16. STS-35 Pilot Gardner and MS Hoffman during egress training at JSC

    Science.gov (United States)

    1990-01-01

    STS-35 Pilot Guy S. Gardner (standing) and Mission Specialist (MS) Jeffrey A. Hoffman prepare for egress training at JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Gardner and Hoffman, wearing orange launch and entry suits (LESs), adjust their parachute harnesses as they listen to instructions before training begins. The astronaut crewmembers and payload specialists for the scheduled May flight were specifically learning proper measures to take in the event of an emergency on the launch pad necessitating emergency evacuation of the orbiter.

  17. STS-56 Commander Cameron and Pilot Oswald on CCT flight deck in JSC's MAIL

    Science.gov (United States)

    1993-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron, (left) and Pilot Stephen S. Oswald, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), are seated on the forward flight deck of the crew compartment trainer (CCT), a shuttle mockup. Cameron mans the commander station controls and Oswald the pilots station controls during an emergency egress (bailout) simulation. The view was taken from the aft flight deck looking forward and includes Cameron's and Oswald's profiles and the forward flight deck controls and checklists. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  18. STS-57 crewmembers train in JSC's FB Shuttle Mission Simulator (SMS)

    Science.gov (United States)

    1993-01-01

    STS-57 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist 2 (MS2) Nancy J. Sherlock, holding computer diskettes and procedural checklist, discusses equipment operation with Commander Ronald J. Grabe on the middeck of JSC's fixed based (FB) shuttle mission simulator (SMS). Payload Commander (PLC) G. David Low points to a forward locker location as MS3 Peter J.K. Wisoff switches controls on overhead panels MO42F and MO58F, and MS4 Janice E. Voss looks on. The FB-SMS is located in the Mission Simulation and Training Facility Bldg 5.

  19. Spectral properties of simulated impact glasses produced from martian soil analogue JSC Mars-1

    Science.gov (United States)

    Moroz, L. V.; Basilevsky, A. T.; Hiroi, T.; Rout, S. S.; Baither, D.; van der Bogert, C. H.; Yakovlev, O. I.; Fisenko, A. V.; Semjonova, L. F.; Rusakov, V. S.; Khramov, D. A.; Zinovieva, N. G.; Arnold, G.; Pieters, C. M.

    2009-07-01

    To simulate the formation of impact glasses on Mars, an analogue of martian bright soil (altered volcanic soil JSC Mars-1) was melted at relevant oxygen fugacities using a pulsed laser and a resistance furnace. Reduction of Fe3+ to Fe2+ and in some cases formation of nanophase Fe0 in the glasses were documented by Mössbauer spectroscopy and TEM studies. Reflectance spectra for several size fractions of the JSC Mars-1 sample and the glasses were acquired between 0.3 and 25 μm. The glasses produced from the JSC Mars-1 soil show significant spectral variability depending on the method of production and the cooling rate. In general, they are dark and less red in the visible compared to the original JSC Mars-1 soil. Their spectra do not have absorption bands due to bound water and structural OH, have positive spectral slopes in the near-infrared range, and show two broad bands centered near 1.05 and 1.9 μm, typical of glasses rich in ferrous iron. The latter bands and low albedo partly mimic the spectral properties of martian dark regions, and may easily be confused with mafic materials containing olivine and low-Ca pyroxene. Due to their disordered structures and vesicular textures, the glasses show relatively weak absorption features from the visible to the thermal infrared. These weak absorption bands may be masked by the stronger bands of mafic minerals. Positive near-infrared spectral slopes typical of fresh iron-bearing impact or volcanic glasses may be masked either by oxide/dust coatings or by aerosols in the Mars' atmosphere. As a result, impact glasses may be present on the surface of Mars in significant quantities that have been either misidentified as other phases or masked by phases with stronger infrared features. Spectrometers with sufficient spatial resolution and wavelength coverage may detect impact glasses at certain locations, e.g., in the vicinity of fresh impact craters. Such dark materials are usually interpreted as accumulations of mafic

  20. STS-35 crewmembers during fire fighting exercises at JSC fire training pit

    Science.gov (United States)

    1990-01-01

    STS-35 crewmembers extinguish a small blaze during a fire handling training session at JSC Fire Training Pit across from the Gilruth Center Bldg 207. Wearing navy blue flight suits, Mission Specialist (MS) Robert A.R. Parker (second right) and MS John M. Lounge (third left) approach fire while operating a fire extinguishers. The crew was briefed on types of potential blazes and the correct means of controlling each type. Also pictured are (left to right) Commander Vance D. Brand, Payload Specialist Samuel T. Durrance, Pilot Guy S. Gardner, and training officer Al Putnam. STS-35 will mark the first seven-member crew staffing since the Challenger accident of January 1986.

  1. STS-26 crew in JSC Shuttle Mockup and Integration Laboratory Bldg 9A

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers model the new (navy blue) partial pressure suits (launch and entry suits (LESs)) for entry and launch phases before a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Pictured (left to right) are Mission Specialist (MS) David C. Hilmers, Commander Frederick H. Hauck, Pilot Richard O. Covey, MS John M. Lounge, and MS George D. Nelson. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  2. STS-45 payload specialists with crew escape system (CES) mockup at JSC's MAIL

    Science.gov (United States)

    1991-01-01

    STS-45 Atlantis, Orbiter Vehicle (OV) 104, Payload Specialist Dirk D. Frimout (European Space Agency (ESA) Belgian crewmember) (left), backup Payload Specialist Charles R. Chappell (center), and Payload Specialist Byron K. Lichtenberg (right) listen to technician explain the operation of the crew escape system (CES) pole. Frimout is engaging the handle which extends the CES pole out the side hatch. The payload specialists along with the other STS-45 crewmembers are participating in side hatch emergency egress exercises in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A.

  3. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck tests cushion outside the crew compartment trainer (CCT) side hatch. Hauck, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, tumbles out CCT side hatch onto cushion as technicians look on. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A.

  4. STS-31 MS Sullivan exits airlock mockup during JSC WETF underwater simulation

    Science.gov (United States)

    1990-01-01

    STS-31 Mission Specialist (MS) Kathryn D. Sullivan, fully suited in an extravehicular mobility unit (EMU) and holding a semirigid tether (SRT) and ratchet caddy assembly, egresses the airlock (AL) mockup during an underwater simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. The open AL extravehicular (EV) hatch appears in the foreground as Sullivan backs out into the payload bay (PLB). Though no extravehicular activity (EVA) is planned for STS-31, two crewmembers train for contingencies that would necessitate leaving the shirt sleeve environment of Discovery's, Orbiter Vehicle (OV) 103's, cabin and performing chores with their Hubble Space Telescope (HST) payload or related hardware in the PLB.

  5. STS-46 Payload Specialist Malerba on the middeck of JSC's FFT mockup

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis, Orbiter Vehicle (OV) 104, Italian Payload Specialist Franco Malerba with his hand resting on the crew escape system (CES) pole stands on the middeck of the Full Fuselage Trainer (FFT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9. Malerba, wearing a flight suit, familiarizes himself with the operation of the CES pole which extends out the shuttle mockup's open side hatch. The CES pole is used if emergency egress is required during the launch or ascent phase of flight.

  6. Glassmaking Units and Glass Feeders Production——a New Production Development Stage at JSC "Krastsvetmet"

    Institute of Scientific and Technical Information of China (English)

    MALTSEV E. V.; MAMONOV S. N.; DMITRIEV V. A.; KHORIKOV P. A.

    2012-01-01

    JSC "Krastsvetmet" has launched the production of glass melting units (GU) and glass feeders (GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide-forming and reinforcing elements.The proprietary technology for dispersion-stabilized material of PtRh10DS composition having high strength and performance properties has been developed and applied.Combined products production was launched where bushings made of PtRh-20 alloy are welded to the plate of the dispersion-stabilized PtRh10DS material.The manufacture of seamless spinning assemblies has been organized.

  7. Development and Making of New Jewellery Palladium Based Alloys at JSC "Krastsvetmet"

    Institute of Scientific and Technical Information of China (English)

    YEFIMOV V. N.; MAMONOV S. N.; SHULGIN D. R.; YELTSIN S. I.

    2012-01-01

    Complex of research and development work aimed at implementation of jewellery palladium based alloys technology has been carried out at JSC Krastsvetmet.A range of palladium alloys jewellery fabrication has been organized.Compositions of a number of jewellery palladium alloys grade 850,900,950 and 990 have been proposed,their production and application in jewellery manufacture has been organized.To produce palladium alloys induction melting in inert atmosphere and melt pouring into a copper mould has been used.The ingots heat treatment conditions,as well as semi-finished jewelry plastic deformation parameters have been determined.

  8. Human spaceflight technology needs-a foundation for JSC's technology strategy

    Science.gov (United States)

    Stecklein, J. M.

    Human space exploration has always been heavily influenced by goals to achieve a specific mission on a specific schedule. This approach drove rapid technology development, the rapidity of which added risks and became a major driver for costs and cost uncertainty. The National Aeronautics and Space Administration (NASA) is now approaching the extension of human presence throughout the solar system by balancing a proactive yet less schedule-driven development of technology with opportunistic scheduling of missions as the needed technologies are realized. This approach should provide cost effective, low risk technology development that will enable efficient and effective manned spaceflight missions. As a first step, the NASA Human Spaceflight Architecture Team (HAT) has identified a suite of critical technologies needed to support future manned missions across a range of destinations, including in cis-lunar space, near earth asteroid visits, lunar exploration, Mars moons, and Mars exploration. The challenge now is to develop a strategy and plan for technology development that efficiently enables these missions over a reasonable time period, without increasing technology development costs unnecessarily due to schedule pressure, and subsequently mitigating development and mission risks. NASA's Johnson Space Center (JSC), as the nation's primary center for human exploration, is addressing this challenge through an innovative approach in allocating Internal Research and Development funding to projects. The HAT Technology Needs (Tech Needs) Database has been developed to correlate across critical technologies and the NASA Office of Chief Technologist Technology Area Breakdown Structure (TABS). The TechNeeds Database illuminates that many critical technologies may support a single technical capability gap, that many HAT technology needs may map to a single TABS technology discipline, and that a single HAT technology need may map to multiple TABS technology disciplines. Th

  9. Isolation and Identification of Microorganisms in JSC Mars-1 Simulant Soil

    Science.gov (United States)

    Mendez, Claudia; Garza, Elizabeth; Gulati, Poonam; Morris, Penny A.; Allen, Carlton C.

    2005-01-01

    Microorganisms were isolated and identified in samples of JSC Mars-1, a Mars simulant soil. JSC Mars-1 is an altered volcanic ash from a cinder cone south of Mauna Kea, Hawaii. This material was chosen because of its similarity to the Martian soil in physical and chemical composition. The soil was obtained by excavating 40 cm deep in a vegetated area to prevent contamination. In previous studies, bacteria from this soil has been isolated by culturing on different types of media, including minimal media, and using biochemical techniques for identification. Isolation by culturing is successful only for a small percentage of the population. As a result, molecular techniques are being employed to identify microorganisms directly from the soil without culturing. In this study, bacteria were identified by purifying and sequencing the DNA encoding the 16s ribosomal RNA (16s rDNA). This gene is well conserved in species and demonstrates species specificity. In addition, biofilm formation, an indicator of microbial life, was studied with this soil. Biofilms are microbial communities consisting of microbes and exopolysaccharides secreted by them. This is a protective way of life for the microbes as they are more resistant to environmental pressures.

  10. Lyndon B. Johnson Space Center (JSC) proposed dual-use technology investment program in intelligent robots

    Science.gov (United States)

    Erikson, Jon D.

    1994-01-01

    This paper presents an overview of the proposed Lyndon B. Johnson Space Center (JSC) precompetitive, dual-use technology investment project in robotics. New robotic technology in advanced robots, which can recognize and respond to their environments and to spoken human supervision so as to perform a variety of combined mobility and manipulation tasks in various sectors, is an obejective of this work. In the U.S. economy, such robots offer the benefits of improved global competitiveness in a critical industrial sector; improved productivity by the end users of these robots; a growing robotics industry that produces jobs and profits; lower cost health care delivery with quality improvements; and, as these 'intelligent' robots become acceptable throughout society, an increase in the standard of living for everyone. In space, such robots will provide improved safety, reliability, and productivity as Space Station evolves, and will enable human space exploration (by human/robot teams). The proposed effort consists of partnerships between manufacturers, universities, and JSC to develop working production prototypes of these robots by leveraging current development by both sides. Currently targeted applications are in the manufacturing, health care, services, and construction sectors of the U.S. economy and in the inspection, servicing, maintenance, and repair aspects of space exploration. But the focus is on the generic software architecture and standardized interfaces for custom modules tailored for the various applications allowing end users to customize a robot as PC users customize PC's. Production prototypes would be completed in 5 years under this proposal.

  11. Model polymer etching and surface modification by a time modulated RF plasma jet: role of atomic oxygen and water vapor

    Science.gov (United States)

    Luan, P.; Knoll, A. J.; Wang, H.; Kondeti, V. S. S. K.; Bruggeman, P. J.; Oehrlein, G. S.

    2017-01-01

    The surface interaction of a well-characterized time modulated radio frequency (RF) plasma jet with polystyrene, poly(methyl methacrylate) and poly(vinyl alcohol) as model polymers is investigated. The RF plasma jet shows fast polymer etching but mild chemical modification with a characteristic carbonate ester and NO formation on the etched surface. By varying the plasma treatment conditions including feed gas composition, environment gaseous composition, and treatment distance, we find that short lived species, especially atomic O for Ar/1% O2 and 1% air plasma and OH for Ar/1% H2O plasma, play an essential role for polymer etching. For O2 containing plasma, we find that atomic O initiates polymer etching and the etching depth mirrors the measured decay of O atoms in the gas phase as the nozzle-surface distance increases. The etching reaction probability of an O atom ranging from 10-4 to 10-3 is consistent with low pressure plasma research. We also find that adding O2 and H2O simultaneously into Ar feed gas quenches polymer etching compared to adding them separately which suggests the reduction of O and OH density in Ar/O2/H2O plasma.

  12. Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    P. B. Tchounwou

    2005-04-01

    Full Text Available Ultra–wideband (UWB technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5-20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8-24 h post exposure. UWBR exerted a statistically significant (p < 0.05 dose-dependent response in cell viability in both serum-treated and serum free medium (SFM -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.

  13. Pulse Shaping for High Capacity Impulse Radio Ultra-Wideband Wireless Links Under the Russian Spectral Emission Mask

    DEFF Research Database (Denmark)

    Grakhova, Elizaveta P.; Rommel, Simon; Jurado-Navas, Antonio

    2016-01-01

    Two pulse shapes for IR-UWB transmission under the Russian spectral emission mask are proposed and their potential experimentally demonstrated. Pulses based on the hyperbolic secant square function and the frequency B-spline wavelet are shown to enable transmission of 1.25 Gbit/s signals, reachin...

  14. An Analysis of the Feasibility of Implementing Ultra Wideband and Mesh Network Technology in Support of Military Operations

    Science.gov (United States)

    2005-03-01

    Link Quality MID Multiple Interface Declaration MMRP Mobile Mesh Routing Protocol MPR Multipoint Relay NIC Network Interface Card NLQ...Neighbor Link Quality NOC Network Operations Center NPS Naval Postgraduate School OLSR Optimized Link State Routing xvi OSI Open System...information is at the Camp Roberts Network Operations Center ( NOC ), the information is processed and sent to the Naval Postgraduate School Global

  15. An Ultra Wideband VHF CMOS LC VCO%超宽频带VHF频段CMOS LC VCO

    Institute of Scientific and Technical Information of China (English)

    宁彦卿; 王志华; 陈弘毅

    2006-01-01

    This paper presents a VHF CMOS VCO. The most significant improvement on the VCO is that the cross-coupled MOSFET pairs are divided into several switchable parts so the characteristics can compensate the state change that results from the frequency tuning of the oscillator. This VCO is implemented in 0.18μm CMOS with a core area of about 550μm × 700μm. The test results show that the tuning range covers 31~111MHz with a power consumption between 0.3~6.9mW and a phase noise at a 100kHz offset of about - 110dBc/Hz.%实现了一个宽频带VHF频段CMOS VCO.其最大的改进在于将振荡器中交叉耦合MOS管分为并联可开关的若干段.这样使其特性可以在较大范围内补偿VCO调频过程中状态的变化.该VCO使用标准0.18μmCMOS工艺制作,核心版图面积约为550μm×700μm.测试结果表明:该VCO频率覆盖范围为31~111MHz;功耗为0.3~6.9mW;在100kHz频偏处相位噪声约-110dBc/Hz.

  16. Time-Reversal Based Range Extension Technique for Ultra-wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    Science.gov (United States)

    2009-04-16

    physical PCB routing limitation in the cable -connector adapting PCB. A high speed ribbon cable /bus has been successfully used to connect the DAC...and the FPGA board in the transmitter. However, It is doubtable for this type of cables to meet our higher sampling rate requirement. One solution to...frequency • Local Oscillator: MITEQ LPLM15000 with 8 GHz - 15 GHz output frequency • PA: MITEQ AMF -6B-08001800-60-34P with 8 GHz - 18 GHz frequency

  17. 10Gb/s Ultra-Wideband Wireless Transmission Based on Multi-Band Carrierless Amplitude Phase Modulation

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2016-01-01

    In this paper, for the first time, a record UWB transmission of 10Gb/s is experimentally demonstrated employing a multi-band approach of carrierless amplitude phase modulation (MultiCAP). The proposed solution complies with the restrictions on the effective radiated power established by both...

  18. Spectrum-averaged Harmonic Path (SHAPA) algorithm for non-contact vital sign monitoring with ultra-wideband (UWB) radar.

    Science.gov (United States)

    Van Nguyen; Javaid, Abdul Q; Weitnauer, Mary Ann

    2014-01-01

    We introduce the Spectrum-averaged Harmonic Path (SHAPA) algorithm for estimation of heart rate (HR) and respiration rate (RR) with Impulse Radio Ultrawideband (IR-UWB) radar. Periodic movement of human torso caused by respiration and heart beat induces fundamental frequencies and their harmonics at the respiration and heart rates. IR-UWB enables capture of these spectral components and frequency domain processing enables a low cost implementation. Most existing methods of identifying the fundamental component either in frequency or time domain to estimate the HR and/or RR lead to significant error if the fundamental is distorted or cancelled by interference. The SHAPA algorithm (1) takes advantage of the HR harmonics, where there is less interference, and (2) exploits the information in previous spectra to achieve more reliable and robust estimation of the fundamental frequency in the spectrum under consideration. Example experimental results for HR estimation demonstrate how our algorithm eliminates errors caused by interference and produces 16% to 60% more valid estimates.

  19. Asymmetric underlap spacer layer enabled nanoscale double gate MOSFETs for design of ultra-wideband cascode amplifiers

    Science.gov (United States)

    Roy, Debapriya; Biswas, Abhijit

    2017-10-01

    Using extensive numerical analysis we investigate effects of asymmetric sidewall spacers on various device parameters of 20-nm double gate MOSFETs associated with analog/RF applications. Our studies show that the device with underlap drain-side spacer length LED of 10 nm and source-side spacer length LES of 5 nm shows improvement in terms of the peak value of transconductance efficiency, voltage gain Av, unity-gain cut-off frequency fT and maximum frequency of oscillations fMAX by 8.6%, 51.7%, 5% and 10.3%, respectively compared to the symmetric 5 nm underlap spacer device with HfO2 spacer of dielectric constant k = 22. Additionally, a higher spacer dielectric constant increases the peak Av while decreasing both peak fT and fMAX. The detailed physical insight is exploited to design a cascode amplifier which yields an ultra-wide gain bandwidth of 2.48 THz at LED = 10 nm with a SiO2 spacer.

  20. Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    Science.gov (United States)

    2008-07-16

    N00014-07-1-0529 Prepared by C) Robert C. Qiu "* (Principal Investigator) 0 together with (Contributing Researchers at Wireless Networking Systems Lab...connection between an FPGA and an ADC (or DAC) is still a bottleneck that restricts the system perfomance. These issues are covered in this report. The...Advanced DSP48E slices, featuring 25-bits x 18-bit two’s complement multiplier, optional pipeline stages for enhanced performance and optional 48

  1. Method of achieving ultra-wideband true-time-delay beam steering for active electronically scanned arrays

    Energy Technology Data Exchange (ETDEWEB)

    Loui, Hung; Brock, Billy C.

    2016-10-25

    The various embodiments presented herein relate to beam steering an array antenna by modifying intermediate frequency (IF) waveforms prior to conversion to RF signals. For each channel, a direct digital synthesis (DDS) component can be utilized to generate a waveform or modify amplitude, timing and phase of a waveform relative to another waveform, whereby the generation/modification can be performed prior to the IF input port of a mixer on each channel. A local oscillator (LO) signal can be utilized to commonly drive each of the mixers. After conversion at the RF output port of each of the mixers, each RF signal can be transmitted by a respective antenna element in the antenna array. Initiation of transmission of each RF signal can be performed simultaneously at each antenna. The process can be reversed during receive whereby timing, amplitude, and phase of the received can be modified digitally post ADC conversion.

  2. Time-Reversal Based Range Extension Technique for Ultra-wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    Science.gov (United States)

    2007-10-16

    1999. [93] H. Song, "Iterative Time Reversal in the Ocean," J. Acoust. Soc. Am., vol. 105, no. 6. [94] S. Kim, G. Edelmann , W. Kuperman, W. Hodgkiss, and...Channel Time-Reversal Acoustics," Appl. Phys. Lett., vol. 80, pp. 694-696, 2002. [97] G. Edelmann , T. Akal, W. Hodgkiss, S. Kim, K. W.A., and H. Song, "An

  3. Time-Reversal Based Range Extension technique for Ultra-wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    Science.gov (United States)

    2010-01-28

    which integrates two 3 Gsps 8-bit ADCs, a clock circuitry, 2 banks of 1GByte DDR2 Memory each and a Xilinx Virtex5 LX110T-3 FPGA, under the 3U format...XC5VLX110T-3 (fastest speed grade available). Two DDR2 memory banks are accessible by the FPGA in order to store data on the fly. An SHB connector is

  4. ANALYSIS OF TRAIN SHEET IN THE INFORMATION SYSTEM OF JSC «UKRZALIZNYTSIA»: PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    S. M. Ovcharenko

    2016-04-01

    Full Text Available Purpose. The system of train sheet analysis (TSA in the information system of JSC «Ukrzaliznytsia» provides work with passenger and suburban trains and has considerable potential. Therefore it is necessary to establish the prospects of development of the system. Methodology. Departments’ setup and the train delay causes should be carried out at every station and span, where such delays took place. This requires the fixation of condition deviations of infrastructure from normal and other adverse factors. In the sector of freight transportations the train schedule analysis is insufficient, since this analysis does not account for deviations from the terms of delivery. Therefore it also is necessary to analyze the delivery graphs. The basis for monitoring the cargo delivery is the method of control time points (CTP of technological operations performed with cargo at railway stations. On the basis of CTP to assess the quality of the transport process one should calculate the values of the analysis of cargo delivery schedule (performance level of the cargo delivery schedule, the coefficient of ahead of schedule/delay delivery. Findings. The article proposes to develop the system TSA using the input and display of the train delay causes on-line by transportation service employees, expansion of statistical databases and processing of the input delay causes during its calculation train sheet analysis of freight trains and quality assessment of the delivery schedule fulfillment. It is also appropriate before the new operator companies had appeared to make changes in the instructions TSCHU-TSD-0002 on the list of departments, which include delayed trains, by adding «the department» «The fault of operator companies» and corresponding causes of delays. Originality. The scheme of automated TSA in the information system of JSC «Ukrzaliznytsia» was improved. The author proposes to determine the cargo delivery quality on the certain polygon using the

  5. Technology Development and Production of Certain Chemical Platinum Metals Compounds at JSC "Krastsvetmet"

    Institute of Scientific and Technical Information of China (English)

    ILYASHEVICH V.D.; PAVLOVA E.I.; KORITSKAYA N.G.; MAMONOV S.N.; SHULGIN D.R.; MALTSEV E.V.

    2012-01-01

    In recent years JSC "Krastsvetmet" has successfully developed the production of chemically pure compounds of precious metals.Currently methods have been developed and facilities have been provided for industrial production of the following platinum metals compounds:- Rhodium (Ⅲ) chloride hydrate,rhodium (Ⅲ) chloride solution,rhodium ( Ⅲ) nitrate solution,rhodium ( Ⅲ)iodide,rhodium ( Ⅲ) sulfate,hydrated rhodium ( Ⅲ) oxide,ammonium hexachlororodiate,rhodium ( Ⅲ)phosphate solution,rhodium electrolytes;Iridium (Ⅳ) chloride hydrate,iridium (Ⅲ) chloride hydrate,ammonium hexachloroiridate (Ⅳ),hexachloriridium acid solution,hexachloriridium crystalline acid;- Ruthenium (Ⅲ) chloride hydrate,ruthenium (Ⅳ) hydroxide chloride,ruthenium (Ⅳ) hydroxide chloride solution,ammonium hexachlororuthenate,ruthenium (Ⅲ) chloride solution,potassium,diaquaoctachloronitrido diruthenate.The quality of the production meets the requirements of Russian and foreign consumers.

  6. STS-26 MS Hilmers during egress training at JSC's MAIL full fuselage trainer

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers, wearing a launch and entry suit (LES) and launch and entry helmet (LEH), tries out the new crew escape system (CES) inflated slide during an emergency egress training exercise in JSC's Shuttle Mockup and Integration Laboratory (MAIL) Bldg 9A. Technicians stand on either side of the slide ready to help Hilmers to his feet once he reaches the bottom. Watching from floor level at the far left is astronaut Steven R. Nagel. A second crewmember stands in the open side hatch of the Full Fuselage Trainer (FFT) awaiting his turn to slide to 'safety'. During Crew Station Review (CSR) #3, the crew donned the new (navy blue) partial pressure suits (LESs) and checked out CES slide and other CES configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. The CES pole extends out the side hatch just above Hilmers' head.

  7. STS-26 Pilot Covey during egress training at JSC's MAIL full fuselage trainer

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing a launch and entry suit (LES) and launch and entry helmet (LEH), slides to safety using the new crew escape system (CES) inflated slide during an emergency egress training exercise in JSC's Shuttle Mockup and Integration Laboratory (MAIL) Bldg 9A. Technicians stand on either side of the slide ready to help Covey to his feet once he reaches the bottom. The CES pole extends out the open side hatch of the Full Fuselage Trainer (FFT). During Crew Station Review (CSR) #3, the crew donned the new (navy blue) partial pressure suits (LESs) and checked out CES slide and other CES configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  8. Measurement of Apparent Thermal Conductivity of JSC-1A Under Ambient Pressure

    Science.gov (United States)

    Yuan, Zeng-Guang; Kleinhenz, Julie E.

    2011-01-01

    The apparent thermal conductivity of JSC-1A lunar regolith simulant was measured experimentally using a cylindrical apparatus. Eleven thermocouples were embedded in the simulant bed to obtain the steady state temperature distribution at various radial, axial, and azimuthal locations. The high aspect ratio of a cylindrical geometry was proven to provide a one-dimensional, axisymmetric temperature field. A test series was performed at atmospheric pressure with varying heat fluxes. The radial temperature distribution in each test fit a logarithmic function, indicating a constant thermal conductivity throughout the soil bed. However, thermal conductivity was not constant between tests at different heat fluxes. This variation is attributed to stresses created by thermal expansion of the simulant particles against the rigid chamber wall. Under stress-free conditions (20 deg C), the data suggest a temperature independent apparent conductivity of 0.1961 +/- 0.0070 W/m/ deg C

  9. STS-47 crew during fire fighting exercises at JSC's Fire Training Pit

    Science.gov (United States)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, crewmembers line up along water hoses to extinguish a blaze in JSC's Fire Training Pit during fire fighting exercises. Manning the hose in the foreground are Payload Specialist Mamoru Mohri, holding the hose nozzle, backup Payload Specialist Takao Doi, Mission Specialist (MS) Jerome Apt, and Commander Robert L. Gibson, at rear. Lined up on the second hose are Pilot Curtis L. Brown, Jr, holding the hose nozzle, followed by MS N. Jan Davis, MS and Payload Commander (PLC) Mark C. Lee, and backup Payload Specialist Stan Koszelak. A veteran firefighter monitors the effort from a position between the two hoses. In the background, backup Payload Specialist Chiaki Naito-Mukai, donning gloves, and MS Mae C. Jemison look on. The Fire Training Pit is located across from the Gilruth Center Bldg 207. Mohri, Doi, and Mukai all represent Japan's National Space Development Agency (NASDA).

  10. Student experimenter stands near middeck lockers in JSC Bldg 9A mockup

    Science.gov (United States)

    1991-01-01

    Student experimenter Constantine Costes, STS-42 Commander Ronald J. Grabe, STS-42 Mission Specialist (MS) William F. Readdy, and Integration Engineer Neal Christie discuss Coates' student experiment 83-02 (SE 83-02) entitled 'Zero-G Capillary Rise of Liquid through Granular Porous Media' in JSC Mockup and Integration Laboratory Bldg 9A Full Fuselage Trainer (FFT). On FFT middeck, Costes stands behind Readdy (kneeling) as Christie demonstrates experiment setup and Grabe looks on (47326). The team also examines experiment components at middeck stowage locker (47323) and at FFT open side hatch (47324, 47325). The experiment is designed to investigate the capillary and forced flow characteristics of blue-tinted water in three glass tubes with three sizes of glass beads. SE 83-02 is scheduled to be flown on STS-42 aboard Discovery, Orbiter Vehicle (OV) 103.

  11. STS-33 crewmembers during training exercise in JSC Mockup and Integration Lab

    Science.gov (United States)

    1989-01-01

    STS-33 Discovery, Orbiter Vehicle (OV) 103, crewmembers, wearing orange launch and entry suits (LESs) and launch and entry helmets (LEHs), are seated in their launch and entry positions on crew compartment trainer (CCT) flight deck during a training exercise in JSC Mockup and Integration Laboratory (MAIL) Bldg 9A. Commander Frederick D. Gregory (far right) is stationed at forward flight deck commanders controls, Pilot John E. Blaha (far left) at the pilots controls and on aft flight deck are mission specialists Manley L. Carter, Jr (left), MS F. Story Musgrave (center, holding clipboard), and MS Kathryn C. Thornton (standing). Overhead forward control panels are visible above the astronauts and aft flight deck onorbit station control panels and windows are visible in the background. Thornton is on the flight deck for this photo but during launch and entry will be seated on the middeck.

  12. STS-29 MS Bagian during post landing egress exercises in JSC FFT mockup

    Science.gov (United States)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) James P. Bagian works his way down to 'safety' using a sky-genie device during post landing emergency egress exercises in JSC full fuselage trainer (FFT) located in the Mockup and Integration Laboratory Bldg 9A. Bagian, wearing orange launch and entry suit (LES) and launch and entry helmet (LEH), lowers himself using the sky genie after egressing from crew compartment overhead window W8. Fellow crewmembers and technicians watch Bagian's progress. Standing in navy blue LES is MS Robert C. Springer with MS James F. Buchli seated behind him on his right and Pilot John E. Blaha seated behind him on his left. Bagian is one of several astronauts who has been instrumental in developing the new crew escape system (CES) equipment (including parachute harness).

  13. STS-26 crewmembers during training exercise in JSC Mockup and Integration Lab

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers, wearing navy blue launch and entry suits (LESs) and launch and entry helmets (LEHs), are seated in their launch and entry positions on crew compartment trainer (CCT) flight deck during a training exercise in JSC Mockup and Integration Laboratory Bldg 9A. Commander Frederick H. Hauck (far right) is stationed at forward flight deck commanders controls, Pilot Richard O. Covey (far left) at the pilots controls and on aft flight deck are mission specialists John M. Lounge (left) and David C. Hilmers. Overhead forward control panels are visible above the astronauts and aft flight deck onorbit station control panels and windows are visible in the background. NOTE: Photo was taken by William H. Bowers, crew photo instructor, with wide angle lens.

  14. STS-40 crew trains in JSC's SLS mockup located in Bldg 36

    Science.gov (United States)

    1987-01-01

    STS-40 Payload Specialist Millie Hughes-Fulford along with backup payload specialist Robert Ward Phillips familiarize themselves with Spacelab Life Sciences 1 (SLS-1) equipment. The two scientists are in JSC's Life Sciences Project Division (LSPD) SLS mockup located in the Bioengineering and Test Support Facility Bldg 36. Hughes-Fulford, in the center aisle, pulls equipment from an overhead stowage locker while Phillips, in the foreground, experiments with the baroreflex neck pressure chamber at Rack 11. The baroreflex collar will be used in conjuction with Experiment No. 022, Influence of Weightlessness Upon Human Autonomic Cardiovascular Control. Behind Phillips in the center aisle are body mass measurement device (BMMD) (foreground) and the stowed bicycle ergometer.

  15. STS-26 crew training in JSC Shuttle Mockup and Integration Laboratory Bldg 9A

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers use a bit of orchestrated humor to demonstrate the aft (back) zipper feature on the new (navy blue) partial pressure suits (launch and entry suits (LESs)) before a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Left to right are Commander Frederick H. Hauck, Mission Specialist (MS) George D. Nelson, MS David C. Hilmers, MS John M. Lounge, and Pilot Richard O. Covey. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  16. Delay time modulation induced oscillating synchronization and intermittent anticipatory/lag and complete synchronizations in time-delay nonlinear dynamical systems.

    Science.gov (United States)

    Senthilkumar, D V; Lakshmanan, M

    2007-03-01

    Existence of a new type of oscillating synchronization that oscillates between three different types of synchronizations (anticipatory, complete, and lag synchronizations) is identified in unidirectionally coupled nonlinear time-delay systems having two different time-delays, that is feedback delay with a periodic delay time modulation and a constant coupling delay. Intermittent anticipatory, intermittent lag, and complete synchronizations are shown to exist in the same system with identical delay time modulations in both the delays. The transition from anticipatory to complete synchronization and from complete to lag synchronization as a function of coupling delay with suitable stability condition is discussed. The intermittent anticipatory and lag synchronizations are characterized by the minimum of the similarity functions and the intermittent behavior is characterized by a universal asymptotic -32 power law distribution. It is also shown that the delay time carved out of the trajectories of the time-delay system with periodic delay time modulation cannot be estimated using conventional methods, thereby reducing the possibility of decoding the message by phase space reconstruction.

  17. Leak Rate Performance of Silicone Elastomer O-Rings Contaminated with JSC-1A Lunar Regolith Simulant

    Science.gov (United States)

    Oravec, Heather Ann; Daniels, Christopher C.

    2014-01-01

    Contamination of spacecraft components with planetary and foreign object debris is a growing concern. Face seals separating the spacecraft cabin from the debris filled environment are particularly susceptible; if the seal becomes contaminated there is potential for decreased performance, mission failure, or catastrophe. In this study, silicone elastomer O-rings were contaminated with JSC- 1A lunar regolith and their leak rate performance was evaluated. The leak rate values of contaminated O-rings at four levels of seal compression were compared to those of as-received, uncontaminated, O-rings. The results showed a drastic increase in leak rate after contamination. JSC-1A contaminated O-rings lead to immeasurably high leak rate values for all levels of compression except complete closure. Additionally, a mechanical method of simulant removal was examined. In general, this method returned the leak rate to as-received values.

  18. Evaluating the Effectiveness of Internal Corporate Controls in Coal Mines Illustrated By the Example of JSC “SUEK-Kuzbass”

    OpenAIRE

    Kucherova Elena; Ponkratova Tamara; Tyuleneva Tatiana; Cherepanova Natalia

    2017-01-01

    The article gives reasons for the need to develop the mechanism and tools of performance evaluation based on the implementation of specific management functions, as well as the integrated evaluation of the effectiveness of internal corporate controls. It presents the approbation of the proposed assessment methodology on the example of JSC “SUEK-Kuzbass”. The monitoring role as one of the functions of management is constantly increasing in the market economy. The participation of Russian compa...

  19. Enhanced removal of Zn(2+) or Cd(2+) by the flocculating Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Zhao, Xin-Qing; Chen, Li-Jie; Chang, Jo-Shu; Bai, Feng-Wu

    2015-05-30

    Microalgae are attracting attention due to their potentials in mitigating CO2 emissions and removing environmental pollutants. However, harvesting microalgal biomass from diluted cultures is one of the bottlenecks for developing economically viable processes for this purpose. Microalgal cells can be harvested by cost-effective sedimentation when flocculating strains are used. In this study, the removal of Zn(2+) and Cd(2+) by the flocculating Chlorella vulgaris JSC-7 was studied. The experimental results indicated that more than 80% Zn(2+) and 60% Cd(2+) were removed by the microalgal culture within 3 days in the presence up to 20.0mg/L Zn(2+) and 4.0mg/L Cd(2+), respectively, which were much higher than that observed with the culture of the non-flocculating C. vulgaris CNW11. Furthermore, the mechanism underlying this phenomenon was explored by investigating the effect of Zn(2+) and Cd(2+) on the growth and metabolic activities of the microalgal strains. It was found that the flocculation of the microalga improved its growth, synthesis of photosynthetic pigments and antioxidation activity under the stressful conditions, indicating a better tolerance to the heavy metal ions for a potential in removing them more efficiently from contaminated wastewaters, together with a bioremediation of other nutritional components contributed to the eutrophication of aquatic ecosystems.

  20. Characterization of the flocculating agent from the spontaneously flocculating microalga Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Guo, Suo-Lian; Zhao, Xin-Qing; Huang, Zih-You; Yang, Yu-Liang; Chang, Jo-Shu; Bai, Feng-Wu

    2014-07-01

    High cost of biomass recovery is one of the bottlenecks for developing cost-effective processes with microalgae, particularly for the production of biofuels and bio-based chemicals through biorefinery, and microalgal biomass recovery through cell flocculation is a promising strategy. Some microalgae are naturally flocculated whose cells can be harvested by simple sedimentation. However, studies on the flocculating agents synthesized by microalgae cells are still very limited. In this work, the cell flocculation of a spontaneously flocculating microalga Chlorella vulgaris JSC-7 was studied, and the flocculating agent was identified to be cell wall polysaccharides whose crude extract supplemented at low dosage of 0.5 mg/L initiated the more than 80% flocculating rate of freely suspended microalgae C. vulgaris CNW11 and Scenedesmus obliquus FSP. Fourier transform infrared (FTIR) analysis revealed a characteristic absorption band at 1238 cm(-1), which might arise from PO asymmetric stretching vibration of [Formula: see text] phosphodiester. The unique cell wall-associated polysaccharide with molecular weight of 9.86×10(3) g/mol, and the monomers consist of glucose, mannose and galactose with a molecular ratio of 5:5:2. This is the first time to our knowledge that the flocculating agent from C. vulgaris has been characterized, which could provide basis for understanding the cell flocculation of microalgae and breeding of novel flocculating microalgae for cost-effective biomass harvest.

  1. JSC Advanced Curation: Research and Development for Current Collections and Future Sample Return Mission Demands

    Science.gov (United States)

    Fries, M. D.; Allen, C. C.; Calaway, M. J.; Evans, C. A.; Stansbery, E. K.

    2015-01-01

    Curation of NASA's astromaterials sample collections is a demanding and evolving activity that supports valuable science from NASA missions for generations, long after the samples are returned to Earth. For example, NASA continues to loan hundreds of Apollo program samples to investigators every year and those samples are often analyzed using instruments that did not exist at the time of the Apollo missions themselves. The samples are curated in a manner that minimizes overall contamination, enabling clean, new high-sensitivity measurements and new science results over 40 years after their return to Earth. As our exploration of the Solar System progresses, upcoming and future NASA sample return missions will return new samples with stringent contamination control, sample environmental control, and Planetary Protection requirements. Therefore, an essential element of a healthy astromaterials curation program is a research and development (R&D) effort that characterizes and employs new technologies to maintain current collections and enable new missions - an Advanced Curation effort. JSC's Astromaterials Acquisition & Curation Office is continually performing Advanced Curation research, identifying and defining knowledge gaps about research, development, and validation/verification topics that are critical to support current and future NASA astromaterials sample collections. The following are highlighted knowledge gaps and research opportunities.

  2. NASA-JSC Protocol for the Characterization of Single Wall Carbon Nanotube Material Quality

    Science.gov (United States)

    Arepalli, Sivaram; Nikolaev, Pasha; Gorelik, Olga; Hadjiev, Victor; Holmes, William; Devivar, Rodrigo; Files, Bradley; Yowell, Leonard

    2010-01-01

    It is well known that the raw as well as purified single wall carbon nanotube (SWCNT) material always contain certain amount of impurities of varying composition (mostly metal catalyst and non-tubular carbon). Particular purification method also creates defects and/or functional groups in the SWCNT material and therefore affects the its dispersability in solvents (important to subsequent application development). A number of analytical characterization tools have been used successfully in the past years to assess various properties of nanotube materials, but lack of standards makes it difficult to compare these measurements across the board. In this work we report the protocol developed at NASA-JSC which standardizes measurements using TEM, SEM, TGA, Raman and UV-Vis-NIR absorption techniques. Numerical measures are established for parameters such as metal content, homogeneity, thermal stability and dispersability, to allow easy comparison of SWCNT materials. We will also report on the recent progress in quantitative measurement of non-tubular carbon impurities and a possible purity standard for SWCNT materials.

  3. Evaluating the effectiveness of the use of fixed assets defense enterprises (by the example of JSC “Concern ‘Sozvezdie’”

    Directory of Open Access Journals (Sweden)

    A. I. Khorev

    2016-01-01

    Full Text Available Currently, the problem of sustainable development of enterprises of the Russian military-industrial complex has not only military, but economic importance. The article provides an analysis of the availability, scope, composition and structure of the basic production assets of JSC "Concern "Sozvezdie" for 2013-2015, and analysis of efficiency of use of the basic production assets in JSC "Concern "Sozvezdie" for 2013-2015. JSC "Concern "Sozvezdie" JSC approved the program of innovative development and technological modernization, the development objective of which is the proved choice of the list and content of activities, the implementation of which should ensure the development of the Concern as a scientific and industrial socio-economic system – a holistic entity. Assessment of the dynamics of the basic production assets has shown that the security of JSC "Concern "Sozvezdie" OPF for 2013-2015 increased by 89,81%. The degree of updating of production assets during the period was 50.7%. The analysis of the efficiency of the basic production assets in JSC "Concern "Sozvezdie" has shown that for every 1% increase in revenue major funds have grown by 0.65%. The rate of fondamenti decreased by 18.2%. The assessment of efficiency of use of the basic production assets of JSC "Concern "Sozvezdie" shows that the total technical re-equipment of scientific and technological, testing and production and technological base of the enterprises of the Concern is directed on creation of production capacities to ensure serial production of advanced weapons, military and special equipment in the framework of the state defense order, as the main activity of the majority of the companies of the Group, and reconstruction, the expansion and creation of production to the production of innovative civilian products.

  4. 20 K Helium Refrigeration System for NASA-JSC Chamber-A

    Science.gov (United States)

    Homan, J.; Redman, R.; Ganni, V.; Sidi-Yekhelef, A.; Knudsen, P.; Norton, R.; Lauterbach, J.; Linza, R.; Vargas, G.

    2013-01-01

    A new 20 K helium refrigerator installed at NASA Johnson Space Center's Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope. The chamber previously and currently still has helium cryopumping panels (CPP) and LN2 shrouds used to create Low Earth Orbit environments. Now with the new refrigerator and new helium shrouds (45 x 65 ) the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Labs, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate a inverse coefficient of performance better than 70 W/W for a 18 KW load at 20 K (accounting for liquid nitrogen precooling power) that remains essentially constant down to 1/3 of this load. Even at 10 percent of the maximum capacity, the performance is better than 140 W/W at 20K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10kW at 15 K to 100 kW at 100K. The refrigerator is capable of operating at any load temperature from 15K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results.

  5. Additive Manufacturing, Design, Testing, and Fabrication: A Full Engineering Experience at JSC

    Science.gov (United States)

    Zusack, Steven

    2016-01-01

    I worked on several projects this term. While most projects involved additive manufacturing, I was also involved with two design projects, two testing projects, and a fabrication project. The primary mentor for these was Richard Hagen. Secondary mentors were Hai Nguyen, Khadijah Shariff, and fabrication training from James Brown. Overall, my experience at JSC has been successful and what I have learned will continue to help me in my engineering education and profession long after I leave. My 3D printing projects ranged from less than a 1 cubic centimeter to about 1 cubic foot and involved several printers using different printing technologies. It was exciting to become familiar with printing technologies such as industrial grade FDM (Fused Deposition Modeling), the relatively new SLA (Stereolithography), and PolyJet. My primary duty with the FDM printers was to model parts that came in from various sources to print effectively and efficiently. Using methods my mentor taught me and the Stratasys Insight software, I was able to minimize imperfections, hasten build time, improve strength for specific forces (tensile, shear, etc...), and reduce likelihood of a print-failure. Also using FDM, I learned how to repair a part after it was printed. This is done by using a special kind of glue that chemically melts the two faces of plastic parts together to form a fused interface. My first goal with SLA technology was to bring the printer back to operational readiness. In becoming familiar with the Pegasus SLA printer, I researched the leveling, laser settings, and different vats to hold liquid material. With this research, I was successfully able to bring the Pegasus back online and have successfully printed multiple sample parts as well as functional parts. My experience with PolyJet technology has been focused on an understanding of the abilities/limits, costs, and the maintenance for daily use. Still upcoming will be experience with using a composite printer that uses FDM

  6. Sustainable development through innovation (the example of JSC «Concern» Constellation»

    Directory of Open Access Journals (Sweden)

    T. I. Ovchinnikova

    2016-01-01

    Full Text Available In the article the «economic growth» theoretical approaches to the terms and «sustainable development». It is indicated that «sustainable development» is related to the introduction of new technologies and innovations, as well as the mechanisms of perfection economic activity. The concept of «sustainable development» includes the principles of sustainability and balanced-ness, while economic growth is associated with the dominant country economic policy objectives, including innovative factors, with the well-being of its population level: the development of the social structure, from the labor market level and other factors. Prospects of development of the country based on the justification of the socio-economic model of its translational movement in the world civilization. Excessive political risks and economic sanctions have shown that Russia should not rely on foreign imports of high-tech, and the need to develop import substitution. Change the vector of development of the Russian economy made their adjustments to the development of the Voronezh region economy slowed down the speed of displacements, of capital, the regional financial centers develop poorly, due to lack of investment has slowed the growth of innovational and information development. There is a growing dependence of the region on the processes taking place at the international and national levels. In the example of the Voronezh area are considered factors of sustainable development such as the coordination of organizational efforts and financial resources in order to achieve a new quality of the region's population lives, and necessity of formation of a new development paradigm of management in the region, based on the modernization of diversified bath economy and the introduction of mechanisms to ensure the implementation of sustainable development. In view of the innovative-investment activity of JSC «Concern» Constellation «steady growth

  7. INCREASE OF FIRMNESS OF FETTLING OF DSP-2 AT USING THE BURNED MAGNESIA CALCIC FLUX IN CONDITIONS OF JSC «BMZ» – MANAGEMENT COMPANY OF HOLDING «BMK»

    Directory of Open Access Journals (Sweden)

    I. A. Bondarenko

    2013-01-01

    Full Text Available It is shown that the burned magnesia calcic flux of JSC “Complex “Magnesite” production is recommended for industrial use on all steel-smelting units of JSC “BMZ —management company BMK holding” on the basis of positive results on increase in firmness of fettling DSP-2.

  8. Analysis of financial potential of engineering enterprises the example of JSC «TEMP»

    Directory of Open Access Journals (Sweden)

    L.S. Stasiuk

    2014-03-01

    Full Text Available The aim of the article. The aim of the article is the disclosure of theoretical foundations and methodological aspects regarding calculation of basic performance indicators of financial capacity building enterprises using the balance sheet Khmelnytskii JSC «Temp» for the period of 2009-2011 years. The results of the analysis. Intensification of competition between companies is becoming increasingly important. The financial potential of the company determines the competitiveness of business cooperation opportunities, assesses as far as are guaranteed economic interests of the company and its partners in the financial and production relationship. In the current economic conditions the company must improve production efficiency, product competitiveness on the basis of effective forms of management and production management, business revitalization. This generally determines the importance of control over the economic activities of enterprises, which is why determining the financial condition of the company and its optimization is one of the main conditions for successful development. The main objective of financial potential of the company is to optimize financial flows in order to increase the positive financial result. The main factor in shaping the financial capacity of serving the financial position of the company. Determining the financial condition of the company and its optimization is one of the basic conditions for its successful development. Analysis of the financial condition of the company involves determining the estimated characteristics, choice of methods of measurement and characterization of these features on certain principles, assessment of deviations from the standard, generally accepted values. The main target of financial analysis is its assessment and identification of reserves, its stabilization and improvement. Means of implementation of this setup is the organization of economic and financial policy. There is a need to

  9. USE OF METAL RESERVOIRS – JET DAMPERS ON MNLZ-3 OF JSC «BMZ – MANAGEMENT COMPANY OF HOLDING «BMK» AFTER RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    I. A. Bondarenko

    2014-01-01

    Full Text Available Within the period from 2010 to 2013 MNLZ-3 of JSC BMZ has completely solved the problem of metal discharge from pouring boxes at their filling on the first melting in line at pouring of all assortment of steels due to use of metal reservoir jet damper of optimal design and chemical composition.

  10. Partnering with NASA JSC for Community Research Needs; Collaborative and Student Opportunities via Jacobs and Psams Initiative

    Science.gov (United States)

    Danielson, L. R.; Draper, D. S.

    2016-12-01

    NASA Johnson Space Center's (JSC) Astromaterials Research and Exploration Science Division houses a unique combination of laboratories and other assets for conducting cutting-edge planetary research. These facilities have been accessed for decades by outside scientists; over the past five years, the 16 full time contract research and technical staff members in our division have hosted a total of 223 visiting researchers, representing 35 institutions. We intend to submit a proposal to NASA specifically for facilities support and establishment of our laboratories as a collective, PSAMS, Planetary Sample Analyses and Mission Science, which should result in substantial cost savings to PIs who wish to use our facilities. JSC is a recognized NASA center of excellence for curation, and in future will allow PIs easy access to samples in Curation facilities that they have been approved to study. Our curation expertise could also be used for a collection of experimental run products and standards that could be shared and distributed to community members, products that could range from 1 bar controlled atmosphere furnace, piston cylinder, multi-anvil, to shocked products. Coordinated analyses of samples is one of the major strengths of our division, where a single sample can be prepared with minimal destruction for a variety of chemical and structural analyses, from macro to nano-scale. A CT scanner will be delivered August 2016 and installed in the same building as all the other division experimental and analytical facilities, allowing users to construct a 3 dimensional model of their run product and/or starting material before any destruction of their sample for follow up analyses. The 3D printer may also be utilized to construct containers for diamond anvil cell experiments. Our staff scientists will work with PIs to maximize science return and serve the needs of the community. We welcome student visitors, and a graduate semester internship is available through Jacobs.

  11. Cross-Linkable, Solvent-Resistant Fullerene Contacts for Robust and Efficient Perovskite Solar Cells with Increased JSC and VOC.

    Science.gov (United States)

    Watson, Brian L; Rolston, Nicholas; Bush, Kevin A; Leijtens, Tomas; McGehee, Michael D; Dauskardt, Reinhold H

    2016-10-05

    The active layers of perovskite solar cells are also structural layers and are central to ensuring that the structural integrity of the device is maintained over its operational lifetime. Our work evaluating the fracture energies of conventional and inverted solution-processed MAPbI3 perovskite solar cells has revealed that the MAPbI3 perovskite exhibits a fracture resistance of only ∼0.5 J/m(2), while solar cells containing fullerene electron transport layers fracture at even lower values, below ∼0.25 J/m(2). To address this weakness, a novel styrene-functionalized fullerene derivative, MPMIC60, has been developed as a replacement for the fragile PC61BM and C60 transport layers. MPMIC60 can be transformed into a solvent-resistant material through curing at 250 °C. As-deposited films of MPMIC60 exhibit a marked 10-fold enhancement in fracture resistance over PC61BM and a 14-fold enhancement over C60. Conventional-geometry perovskite solar cells utilizing cured films of MPMIC60 showed a significant, 205% improvement in fracture resistance while exhibiting only a 7% drop in PCE (13.8% vs 14.8% PCE) in comparison to the C60 control, enabling larger VOC and JSC values. Inverted cells fabricated with MPMIC60 exhibited a 438% improvement in fracture resistance with only a 6% reduction in PCE (12.3% vs 13.1%) in comparison to those utilizing PC61BM, again producing a higher JSC.

  12. Development of an IVE/EVA Compatible Prototype Cold-Gas Cubesat Propulsion System at NASA/JSC

    Science.gov (United States)

    Radke, Christopher; Studak, Joseph

    2017-01-01

    Cold-gas propulsion systems are well suited for some applications because they are simple to design and build, have low operating costs, and are non-toxic. The inherent tradeoff, however, is their relatively low impulse density. Nevertheless, a modest propulsion system, sized for Cubesats and designed for affordability, presents an attractive system solution for some missions, such as an on-orbit inspection free-flyer. NASA has a long-standing effort to develop propulsion systems appropriate for very high delta-V cubesat missions, such as geo transfer orbits, and there are commercially available Cubesat propulsion systems with considerably more impulse capability, but, these are both prohibitively expensive for some development customers and face compatibility constraints for crewed applications, such as operation within ISS. A relatively conventional cold-gas system has been developed at NASA/JSC taking advantage of existing miniature industrial components, additive manufacturing techniques and in-house qualification of the system. The result is a nearly modular system with a 1U form factor. Compressed nitrogen is stored in a small high-pressure tank, then regulated and distributed to 12 thrusters. Maneuvering thrust can be adjusted, with a typical value of 40 mN, and the delta-V delivered to a 3U Cubesat would be approximately 7 m/s. These values correspond to the performance parameters for an inspection mission previously established at JSC for inspection of the orbiter prior to reentry. Environmental testing was performed to meet ISS launch and workmanship standards, along with the expected thermal environment for an inspection mission. Functionality has been demonstrated, and performance in both vacuum and relevant blow down scenarios was completed. Several avenues for further improvement are also explored. Details of the system, components, integration, tests, and test data are presented in this paper.

  13. 超宽带SAR浅地表地雷聚焦与定位技术%Focusing and Locating of Subsurface Landmines in Ultra-wideband SAR

    Institute of Scientific and Technical Information of China (English)

    金添; 周智敏; 宋千; 常文革

    2007-01-01

    机载或车载超宽带合成孔径雷达可以大区域快速探测单个地雷和雷场,是探雷的发展趋势.由于传统成像算法基于均匀媒质的假设,在浅地表目标成像中不再适应.该文首先建立了浅地表目标回波模型,定量分析了折射和色散对成像的影响.基于回波模型,提出了分别在回波域和图像域补偿折射和色散影响的浅地表后向投影(Subsurface Back-Projection,SBP)成像算法.但是对未知区域进行地雷探测时,无法获得目标埋设深度和入射角先验信息.针对这个问题,提出了基于图像域SBP成像算法的粗、精补偿分级处理流程,实现了大区域多目标精确聚焦定位.最后利用Rail-GPSAR探雷试验系统实测数据验证了该文方法的有效性.

  14. A Low-Power OOK Transmitter for Ultra-Wideband%一种低功耗OOK调制超宽带发射机的实现

    Institute of Scientific and Technical Information of China (English)

    张继红; 方毅; 黄鲁

    2014-01-01

    设计了一种低功耗OOK调制方式的脉冲超宽带发射机.该发射机的中心频率和脉冲宽度可调;优化了偏置电路,使环形振荡器不易受工艺和温度的影响;在传输数据的间隔,关断相应电路,以实现低功耗.基于TSMC 0.13 μm CMOS工艺,对电路进行仿真.结果显示,发射机可以实现1~40 Mb/s的数据传输速率,脉冲宽度为1 ns,中心频率为4 GHz,输出脉冲峰峰值为550mV,功率谱密度符合FCC频谱规范,在10 Mb/s数据传输速率下,功耗为320 μW.

  15. Hardware Implementation of a Genetic Algorithm Based Canonical Singed Digit Multiplierless Fast Fourier Transform Processor for Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband Applications

    Directory of Open Access Journals (Sweden)

    Mahmud Benhamid

    2009-01-01

    Full Text Available Problem statement: Ultra Wide Band (UWB technology has attracted many researchers' attention due to its advantages and its great potential for future applications. The physical layer standard of Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM UWB system is defined by ECMA International. In this standard, the data sampling rate from the analog-to-digital converter to the physical layer is up to 528 M sample sec-1. Therefore, it is a challenge to realize the physical layer especially the components with high computational complexity in Very Large Scale Integration (VLSI implementation. Fast Fourier Transform (FFT block which plays an important role in MB-OFDM system is one of these components. Furthermore, the execution time of this module is only 312.5 ns. Therefore, if employing the traditional approach, high power consumption and hardware cost of the processor will be needed to meet the strict specifications of the UWB system. The objective of this study was to design an Application Specific Integrated Circuit (ASIC FFT processor for this system. The specification was defined from the system analysis and literature research. Approach: Based on the algorithm and architecture analysis, a novel Genetic Algorithm (GA based Canonical Signed Digit (CSD Multiplier less 128-point FFT processor and its inverse (IFFT for MB-OFDM UWB systems had been proposed. The proposed pipelined architecture was based on the modified Radix-22 algorithm that had same number of multipliers as that of the conventional Radix-22. However, the multiplication complexity and the ROM memory needed for storing twiddle factors coefficients could be eliminated by replacing the conventional complex multipliers with a newly proposed GA optimized CSD constant multipliers. The design had been coded in Verilog HDL and targeted Xilinx Virtex-II FPGA series. It was fully implemented and tested on real hardware using Virtex-II FG456 prototype board and logic analyzer. Results: From the synthesis reports, the proposed GA optimized CSD constant complex multiplier achieved 79 and 50% equivalent gates and latency efficiency when compared to the conventional complex multiplier. Conclusion: As a conclusion, we successfully implemented 128-points FFT/IFFT processor with the proposed architecture that can meet the requirement of MB-OFDM UWB system with higher throughput and less area compared to conventional architecture.

  16. InGaAs/InAlAs Five Layer Asymmetric Coupled Quantum Well (FACQW) for Ultra-Wideband Ultrafast Optical Modulators

    Institute of Scientific and Technical Information of China (English)

    Taro Arakawa; Ryuji Iino; Tetsuya Ishie; Terumasa Kawabata; Kunio Tada

    2003-01-01

    An InGaAs/InAlAs five-layer asymmetric coupled quantum well (FACQW) is expected to show very large electrorefractive index change. n in a wideband transparency region. Band structures of the FACQW are analyzed with Luttinger-Kohn Hamiltonian. The electrorefractive characteristics of the FACQW are discussed.

  17. InGaAs/InAlAs Five Layer Asymmetric Coupled Quantum Well (FACQW) for Ultra-Wideband Ultrafast Optical Modulators

    Institute of Scientific and Technical Information of China (English)

    Taro; Arakawa; Ryuji; Iino; Tetsuya; Ishie; Terumasa; Kawabata; Kunio; Tada

    2003-01-01

    An InGaAs/InAlAs five-layer asymmetric coupled quantum well (FACQW) is expected to show very large electrorefractive index change . n in a wideband transparency region. Band structures of the FACQW are analyzed with Luttinger-Kohn Hamiltonian. The electrorefractive characteristics of the FACQW are discussed.

  18. The design of an ultra-wideband miniaturized GPR antenna%一种超宽带小型化探地雷达天线的设计

    Institute of Scientific and Technical Information of China (English)

    彭宇; 王蕾; 郭福强; 胡通海

    2014-01-01

    通过对蝶形偶极子天线复合加载的方式形成一种小型化的探地雷达天线,多种加载方式的引入不但使天线具有宽频带的性能,而且设计的天线尺寸与理论计算尺寸相比也大大减小。在天线后方引入背腔设计,增加了天线的方向性和抗干扰能力。所设计的天线具有1.5~4 GHz的频带宽度,且天线的方向性良好。设计的天线已成功应用于LTD探地雷达2.2 GHz天线系统和3 GHz的液态危险品检测天线系统中。%A kind of miniaturized GPR antenna was designed through complex loading to the bow-tie dipole. The introduction of multi-ple loading methods not only makes the antenna acquire the performance of broadband but also greatly decreases the size of antenna compared with the theoretical calculation size. By introducing back cavity behind the antenna, the directivity and anti-jamming capabili-ty of the antenna are enhanced. The designed antenna possesses a 1.5 GHz~4 GHz frequency band width and a good direction. The de-signed antenna is successfully applied to the antenna system of 2.2 GHz LTD series of GPR. This designed antenna can be also used in the dangerous liquid goods inspection system of 3 GHz LTD series of GPR.

  19. Ultra-Wideband Electromagnetic Radiation from GaAs Photoconductive Switches%基于GaAs光电导开关的超宽带微波源

    Institute of Scientific and Technical Information of China (English)

    施卫; 贾婉丽; 纪卫莉

    2005-01-01

    The experiment results of ultrawide band electromagnetic radiation with DC biased GaAs photoconductive semiconductor switch combining double ridge horn antenna triggered by high repeat frequency femto-second laser pulse are reported.The GaAs switches are insulated by solid multi-layer transparent dielectrics and the distance of two electrodes is 3mm.The electrode material of the switch is ohmic contact through alloy technics with definite proportion of Au/Ge/Ni.This switch and double ridge horn antenna are integrated and the receive antenna is connected with the test instrument.From receiving antenna,ultra fast electrical pulse of 200ps rise time and 500ps pulse width is obtained,the repetition rate of the pulse is about 82MHz and the frequency spectrum is in the range of 4.7MHz~14GHz.The radiation characteristic of the ultrafast electrical pulse is analyzed.%报道了用飞秒激光脉冲触发GaAs光电导开关产生超短电磁脉冲辐射超宽带电磁波的实验结果,分析了超短电脉冲串经宽带天线的辐射特性.在接收端获得了上升时间200ps、脉冲宽度500ps、重复频率82MHz的超短电脉冲串和经宽带天线辐射的超宽带电磁波波形,其电磁波频谱覆盖4.7MHz~14GHz.

  20. Electromagnetic Performances Analysis of an Ultra-wideband and Flexible Material Antenna in Microwave Breast Imaging: To Implement A Wearable Medical Bra.

    Science.gov (United States)

    Rahman, Ashiqur; Islam, Mohammad Tariqul; Singh, Mandeep Jit; Kibria, Salehin; Akhtaruzzaman, Md

    2016-12-23

    In this paper, we report a compact and ultra-wide band antenna on a flexible substrate using the 5-(4-(perfluorohexyl)phenyl)thiophene-2-carbaldehyde compound for microwave imaging. In contrast to other microwave based imaging systems, such as an array of 16 antennas, we proposed a bi-static radar based imaging system consisting of two omnidirectional antennas, which reduces complexity and the overall dimension. The proposed compact antennas are 20 × 14 mm(2) and designed for operating at frequencies from 4 to 6 GHz. To allow for implantation into a bra, the electromagnetic performances of the antennas must be considered in bending conditions. In comparison with the recently reported flexible antennas, we demonstrated both electromagnetic performance and imaging reconstruction for bending conditions. For the proof of concept, the electromagnetic performances both at flat and bending conditions have been verified using a homogeneous multilayer model of the human breast phantom. Our results demonstrate that the antenna, even at bending conditions, exhibits an excellent omni-directional radiation pattern with an average efficiency above 70% and average gain above 1 dBi, within the operational frequency band. The comprehensive aim of the realized antenna is to design a biodegradable and wearable antenna-based bra for early breast cancer detection in the future.

  1. 基于CAM的认知超宽带频谱感知方法%Spectrum Detection for Cognitive Ultra-wideband Based on Cyclic Autocorrelation Matrix

    Institute of Scientific and Technical Information of China (English)

    陈小波; 陈红; 蔡晓霞; 丁敬校

    2012-01-01

    Spectrum sensing is one of key parts for CUWB system, since styles of targeted signals in the UWB spectrum band are predefined, in order to offset shortcomings of autocorrelation detection?which could not distinguish signal styles. This paper presents a sensing method employing the differences of cyclic feature and autocorrelation matrix between signals to distinguish whether the frequencies can be used by cognitive users, this method combines advantages of cyclostationary detection and autocorrelation detection to make a decision cooperatively. The simulation shows that performance of the proposed method is much better than the cyclostationary detection and energy detection both in high and low SNR environment, therefore, this method is fit for CUWB system.%频谱感知是认知超宽带系统的核心部分,针对超宽带频带内授权信号类型确定的特点,为了弥补自相关检测不能够识别信号类型的缺点,提出利用信号的循环谱特征和自相关矩阵差异性来检测授权信号,该方法融合了自相关检测和循环谱检测的优点进行合作判决.仿真表明该方法在高低信噪比环境下均能比循环谱检测和能量检测得到更好地检测效果,因此适合于认知超宽带系统.

  2. Evaluation of the information content of wideband and ultra-wideband radar returns from an F14, F15 and F16 using asymptotic electromagnetic techniques

    CSIR Research Space (South Africa)

    Cilliers, Jacques E

    2012-10-01

    Full Text Available . Returns from an F14, F15 and F16 were simulated using an asymptotic RCS prediction code. The information content of the three targets is evaluated for four sets of radar waveforms....

  3. Ultra-Wideband Optical Modulation Spectrometer (OMS) Development: Study of the Optical Setup of a Wide-Band Optical Modulation Spectrometer

    Science.gov (United States)

    Tolls, Volker; Stringfellow, Guy (Technical Monitor)

    2001-01-01

    The purpose of this study is to advance the design of the optical setup for a wide-band Optical Modulation Spectrometer (OMS) for use with astronomical heterodyne receiver systems. This report describes the progress of this investigation achieved from March until December 2001.

  4. Cultivation of Chlorella vulgaris JSC-6 with swine wastewater for simultaneous nutrient/COD removal and carbohydrate production.

    Science.gov (United States)

    Wang, Yue; Guo, Wanqian; Yen, Hong-Wei; Ho, Shih-Hsin; Lo, Yung-Chung; Cheng, Chieh-Lun; Ren, Nanqi; Chang, Jo-Shu

    2015-12-01

    Swine wastewater, containing a high concentration of COD and ammonia nitrogen, is suitable for the growth of microalgae, leading to simultaneous COD/nutrients removal from the wastewater. In this study, an isolated carbohydrate-rich microalga Chlorella vulgaris JSC-6 was adopted to perform swine wastewater treatment. Nearly 60-70% COD removal and 40-90% NH3-N removal was achieved in the mixotrophic and heterotrophic culture, depending on the dilution ratio of the wastewater, while the highest removal percentage was obtained with 20-fold diluted wastewater. Mixotrophic cultivation by using fivefold diluted wastewater resulted in the highest biomass concentration of 3.96 g/L. The carbohydrate content of the microalga grown on the wastewater can reach up to 58% (per dry weight). The results indicated that the microalgae-based wastewater treatment can efficiently reduce the nutrients and COD level, and the resulting microalgal biomass had high carbohydrate content, thereby having potential applications for the fermentative production of biofuels or chemicals.

  5. Assessment of business customers satisfaction with the products and service of Pnevmostroimashina, jsc, on the B2B market

    Directory of Open Access Journals (Sweden)

    L. M. Kapustina

    2010-12-01

    Full Text Available The paper is dedicated to development of a methodology for assessment of customer satisfaction with the products and services on the b2b market. The study of customer satisfaction is aimed at building strong and mutually beneficial supplier-customer relationship. The authors focus on the importance of customer satisfaction continuous monitoring intended for improvement of the company’s market performance. The research based on the works by Kano N., Lamben J.-J., Carter R., Parashuraman A., Zeitaml V. A., Berry L. L. and others, describes an algorithm study of consumers and offers a methodology to evaluate customer satisfaction with the industrial products. Based on the analysis of the economic crisis effects on the machine-building industry, the authors determine the performance of “Pnevmostroimashina”, JSC, on the road and construction equipment market and illustrate an example of practical use of the customer satisfaction assessment technique in the company. At the end of the paper some recommendations for development of an efficient customer satisfaction measurement procedure are introduced.

  6. Effects of Lunar Dust Simulant (JSC-1A-vf) on WI-38 Human Embryonic Lung Cells

    Science.gov (United States)

    Currie, Stephen; Hammond, Dianne; Jeevarajan, Anthony

    2007-01-01

    In order to develop appropriate countermeasures for NASA's return mission to the moon, the potential toxicity of lunar dust needs to be examined. Due to its abrasiveness, reactivity, composition and small size, lunar dust may pose a serious health risk to astronauts who inhale it. This project focuses on the toxicity of lunar dust simulant (JSC-1A-vf) using WI-38 human embryonic lung cells. Past results show that the simulant has toxic effects on small animals using intratracheal instillation. Earlier studies in this lab suggest that the dust remaining in media after low speed centrifugation is toxic. In order to better assess its toxicity, the simulant has been diluted in media, filtered with a 5 micron filter before combining it with media. This filtered dust is compared with dust centrifuged in media. Whole dust toxicity is also tested. Toxicity is estimated using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) toxicity test which measures the activity of reducing enzymes in the mitochondria of viable cells. Preliminary results suggest that simulant which is diluted in media at different concentrations is slightly toxic. Interestingly, the cells appear to sweep up and collect the simulant. Whether this contributes to its toxicity is unclear. This project provides possible toxicity testing protocols for lunar dust and contributes to the knowledge of nanosize particle toxicity.

  7. Enhancing bio-butanol production from biomass of Chlorella vulgaris JSC-6 with sequential alkali pretreatment and acid hydrolysis.

    Science.gov (United States)

    Wang, Yue; Guo, Wanqian; Cheng, Chieh-Lun; Ho, Shih-Hsin; Chang, Jo-Shu; Ren, Nanqi

    2016-01-01

    This study presents a successful butanol production method using alkali and acid pretreated biomass of Chlorella vulgaris JSC-6. The butanol concentration, yield, and productivity were 13.1g/L, 0.58mol/mol sugar, 0.66g/L/h, respectively. Nearly 2.93L/L of biohydrogen was produced during the acidogenesis phase in ABE fermentation. The hydrogen yield and productivity were 0.39mol/mol sugar and 104.2g/L/h respectively. In addition, the high glucose consumption efficiency (97.5%) suggests that the hydrolysate pretreated with NaOH (1%) followed by H2SO4 (3%) did not contain inhibitors to the fermentation. It was also discovered that an excess amount of nitrogen sources arising from hydrolysis of highly concentrated microalgal biomass negatively affected the butanol production. This work demonstrates the technical feasibility of producing butanol from sustainable third-generation feedstock (i.e., microalgal biomass).

  8. Evaluating the Effectiveness of Internal Corporate Controls in Coal Mines Illustrated By the Example of JSC “SUEK-Kuzbass”

    Directory of Open Access Journals (Sweden)

    Kucherova Elena

    2017-01-01

    Full Text Available The article gives reasons for the need to develop the mechanism and tools of performance evaluation based on the implementation of specific management functions, as well as the integrated evaluation of the effectiveness of internal corporate controls. It presents the approbation of the proposed assessment methodology on the example of JSC “SUEK-Kuzbass”. The monitoring role as one of the functions of management is constantly increasing in the market economy. The participation of Russian companies in the international economy requires the organisation of internal company control. Moreover, with the enacting of the Law “On Accountings» № 402-FZ, for the majority of economic agents the organising of internal control became mandatory. Thus, the internal control means the process carried out by the Board of Directors and other staff of the organisation aimed at providing reasonable assurance that the objectives of the organisation such as ensuring the effectiveness and efficiency of operations, reliability of financial reporting and compliance with the legislation in force will be achieved.

  9. A novel marine bacterium Isoptericola sp. JS-C42 with the ability to saccharifying the plant biomasses for the aid in cellulosic ethanol production.

    Science.gov (United States)

    Santhi, Velayudhan Satheeja; Gupta, Ashutosh; Saranya, Somasundaram; Jebakumar, Solomon Robinson David

    2014-06-01

    The ever growing demands for food products such as starch and sugar produces; there is a need to find the sources for saccharification for cellulosic bioethanol production. This study provides the first evidence of the lignocellulolytic and saccharifying ability of a marine bacterium namely Isoptericola sp. JS-C42, a Gram positive actinobacterium with the cocci cells embedded on mycelia isolated from the Arabian Sea, India. It exhibited highest filter paper unit effect, endoglucanase, exoglucanase, cellobiohydrolase, β-glucosidase, xylanase and ligninase effect. The hydrolytic potential of the enzymes displayed the efficient saccharification capability of steam pretreated biomass. It was also found to degrade the paddy, sorghum, Acacia mangium and Ficus religiosa into simple reducing sugars by its efficient lignocellulose enzyme complex with limited consumption of sugars. Production of ethanol was also achieved with the Saccharomyces cerevisiae. Overall, it offers a great potential for the cellulosic ethanol production in an economically reliable and eco-friendly point-of-care.

  10. ASSESSMENT OF RELIABILITY AND RISK DEGREE FOR ACCIDENT INITIATION AT SLIME STORAGES OF 4th MINING ADMINISTRATION, JSC “BELARUSKALI”

    Directory of Open Access Journals (Sweden)

    P. M. Bohaslauchyk

    2016-01-01

    Full Text Available Definition of reliability for dams of slime storage embankment is given on the basis of reliability theory and characteristics of reliability and their analysis are presented in the paper. The paper specifies qualitative indices for earth dams which are subdivided in two groups: applicability factors and structural reliability factors. A short analysis of all possible causes for accident initiation at earth dams has been made and the analysis has permitted to pinpoint eleven main objects for diagnosis for slime storage dams. In order to assess risk degree of accident initiation at JSC “Belaruskali” slime storages all possible causes of emergency cases and their probability of occurrence have been analyzed in the paper. The paper acknowledges the fact that dam malfunction is possible, as a rule, due to violation of operational rules and regulations. Main parameters of slime storage state which are to be controlled regularly in the process of its operation have been noted in the paper. Observation results over slime storages, calculations of dam slope stability for normal operation (a principal calculation case and operating irregularities in water seals (a special calculation case. As a stability margin factor is close to 1.0 for a special calculation case, an extreme position of depression curve has been determined for all design sections. It has been recommended to carry out a constant control over its position, and in the case when it reaches its peak value it is necessary to undertake appropriate measures in order to reduce its value. Final expert estimations on probability of accident initiation at the investigated slime storage dams of the 4th Mining Administration, JSC “Belaruskali” have been prepared on the basis of the analysis comprising all the required factors. A conclusion has been made about low risk degree of their destruction.

  11. Dynamic metabolic profiling together with transcription analysis reveals salinity-induced starch-to-lipid biosynthesis in alga Chlamydomonas sp. JSC4

    Science.gov (United States)

    Ho, Shih-Hsin; Nakanishi, Akihito; Kato, Yuichi; Yamasaki, Hiroaki; Chang, Jo-Shu; Misawa, Naomi; Hirose, Yuu; Minagawa, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2017-01-01

    Biodiesel production using microalgae would play a pivotal role in satisfying future global energy demands. Understanding of lipid metabolism in microalgae is important to isolate oleaginous strain capable of overproducing lipids. It has been reported that reducing starch biosynthesis can enhance lipid accumulation. However, the metabolic mechanism controlling carbon partitioning from starch to lipids in microalgae remains unclear, thus complicating the genetic engineering of algal strains. We here used “dynamic” metabolic profiling and essential transcription analysis of the oleaginous green alga Chlamydomonas sp. JSC4 for the first time to demonstrate the switching mechanisms from starch to lipid synthesis using salinity as a regulator, and identified the metabolic rate-limiting step for enhancing lipid accumulation (e.g., pyruvate-to-acetyl-CoA). These results, showing salinity-induced starch-to-lipid biosynthesis, will help increase our understanding of dynamic carbon partitioning in oleaginous microalgae. Moreover, we successfully determined the changes of several key lipid-synthesis-related genes (e.g., acetyl-CoA carboxylase, pyruvate decarboxylase, acetaldehyde dehydrogenase, acetyl-CoA synthetase and pyruvate ferredoxin oxidoreductase) and starch-degradation related genes (e.g., starch phosphorylases), which could provide a breakthrough in the marine microalgal production of biodiesel. PMID:28374798

  12. A novel marine bacterium Isoptericola sp. JS-C42 with the ability to saccharifying the plant biomasses for the aid in cellulosic ethanol production

    Directory of Open Access Journals (Sweden)

    Velayudhan Satheeja Santhi

    2014-06-01

    Full Text Available The ever growing demands for food products such as starch and sugar produces; there is a need to find the sources for saccharification for cellulosic bioethanol production. This study provides the first evidence of the lignocellulolytic and saccharifying ability of a marine bacterium namely Isoptericola sp. JS-C42, a Gram positive actinobacterium with the cocci cells embedded on mycelia isolated from the Arabian Sea, India. It exhibited highest filter paper unit effect, endoglucanase, exoglucanase, cellobiohydrolase, β-glucosidase, xylanase and ligninase effect. The hydrolytic potential of the enzymes displayed the efficient saccharification capability of steam pretreated biomass. It was also found to degrade the paddy, sorghum, Acacia mangium and Ficus religiosa into simple reducing sugars by its efficient lignocellulose enzyme complex with limited consumption of sugars. Production of ethanol was also achieved with the Saccharomyces cerevisiae. Overall, it offers a great potential for the cellulosic ethanol production in an economically reliable and eco-friendly point-of-care.

  13. LDPC-coded unitary space-time modulation with low-complexity iterative demodulate-decoding scheme%具有低复杂度的LDPC已编码非相干酉空时调制系统设计

    Institute of Scientific and Technical Information of China (English)

    王利娇; 张林; 杨玲玲; 彭立; 符达伟

    2014-01-01

    提出一种克服无线信道瑞利衰落和高斯白噪声干扰的非相干编码调制MIMO系统方案。纠错码采用IEEE 802.16e 中的非规则 QC-LDPC 码,非相干调制采用基于三角函数的酉空时调制(SC-USTM)。在接收端,推导出SC-USTM的最大后验概率(MAP)解调算法;为了降低复杂度,构造了SC-USTM 的双解调器方案;为了改善双解调的性能,在置信传播(BP)迭代解码器和MAP解调器之间引入了迭代反馈机制。仿真实验表明LDPC已编码SC-USTM的MIMO系统比未编码USTM的MIMO系统在510-误码率时,性能改善15~17 dB,并且整个系统具有较低的计算复杂度。%A practical low-density parity-check(LDPC) coded unitary space-time modulation (USTM) noncoherent MI-MO communication system over Rayleigh flat fading and additive white Gaussian noise (AWGN) channel was con-structed, where the LDPC code is selected from IEEE 802.16e Standard and USTM is constructed by the unitary matrix based on the sinc-cosinc function, SC-USTM for short. At the receiver, the maximum a posteriori probability (MAP) de-modulating algorithm of the SC-USTM was first designed;for reducing the complexity of MAP demodulator, the dual demodulator was then conceived;for improving the performance, the iterative feedback between the belief propagation (BP) decoder and the MPA demodulator was finally introduced. The simulation test shows that the system of the 510-LDPC coded SC-USTM is superior to the uncoded SC-USTM about 15~17 dB at BER , and this system has very low complexity.

  14. 超宽带穿墙雷达取样脉冲产生器设计%Design of a Novel Sampling Pulse Generator for Ultra-Wideband Through-Wall Radar

    Institute of Scientific and Technical Information of China (English)

    郭宇; 朱国富

    2014-01-01

    In the receiver of through-wall radar,equivalent sampling technology is the key technology which requires a narrow and high-amplitude pulse to trigger the sampling gate for sampling. In this paper,the ul-tra-wideband( UWB) pulse technologies are described,and then different approaches for generating UWB pulse are analyzed and compared. The considered pulse generation technologies are based on logic gates, Step-Recovery Diodes( SRD) and avalanche transistors. Furthermore,a novel approach for the sub-nano-second sampling pulse generator of the equivalent sampling receiver is investigated. The basis of the gener-ator is an avalanche transistor and a unique pulse-shaping circuit,which is composed of the Schottky diode and used to reduce the pulse width and maintain the higher pulse amplitude. Finally,the sampling pulse generator with pulse duration of 400 ps,pulse amplitude of 6. 46 V and ringing level of -14. 7 dB is simu-lated and fabricated. Good agreement between the measured and simulation results is achieved. With the features such as simple structure,stable performance and low cost,the proposed design is ideal for the sam-pling pulse of the UWB equivalent sampling receiver.%在超宽带穿墙雷达接收机系统中,其关键的等效采样技术需要一种极窄脉宽高电压的脉冲触发采样门电路来对接收信号进行采样。介绍了超宽带取样脉冲产生技术,讨论并分析了几种常用超宽带脉冲产生方法的特点及其局限性。提出了新型的肖特基二极管脉冲整形网络,设计并实现了应用于等效采样接收机系统的新型亚纳秒取样脉冲产生器,很好地结合了雪崩晶体管与脉冲整形网络的优势,在显著减小脉宽的同时保持了较高的脉冲幅度。通过仿真分析和制作测试,获得了脉冲底宽为400 ps、幅度为6.46 V和波动水平为-14.7 dB的单极性窄脉冲,实测结果与设计数值一致性良好。这种简单高效廉价的电路十分符合超宽带穿墙雷达等效采样接收机取样脉冲的设计。

  15. Performance of a 60-GHz DCM-OFDM and BPSK-Impulse Ultra-Wideband System with Radio-Over-Fiber and Wireless Transmission Employing a Directly-Modulated VCSEL

    DEFF Research Database (Denmark)

    Beltrán, Marta; Jensen, Jesper Bevensee; Yu, Xianbin

    2011-01-01

    good tolerance to chromatic dispersion due to the chirp characteristics of electro-optical conversion when a directly-modulated VCSEL is employed. The performance comparison indicates that BPSK-IR UWB exhibits better tolerance to optical transmission impairments requiring lower received optical power....../s bitrate. The two UWB implementations considered employ dual-carrier modulation orthogonal frequency-division multiplexing (DCM-OFDM) and binary phase-shift keying impulse radio (BPSK-IR) modulation respectively. Optical transmission distances up to 40 km in standard single-mode fiber and up to 500 m...

  16. 基于模糊超球面支持向量机的超宽带SAR地雷检测%Ultra-wideband SAR Landmine Detection Using Fuzzy Hypersphere Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    金添; 周智敏; 宋千; 常文革

    2007-01-01

    机载或车载超宽带合成孔径雷达(UWB SAR)可以大区域快速探测单个地雷和雷场,是探雷的发展趋势.虚警太多是UWB SAR探雷实用化的主要问题.本文提出了模糊超球面支持向量机(FHS-SVM)地雷检测器.FHS-SVM在高维核特征空间中构造封闭的超球面区分地雷和杂波,并在学习过程中利用隶属度定量表征地雷和杂波误判风险不同及地雷埋设环境变化等因素对检测器的影响.轨道地表穿透SAR(Rail-GPSAR)系统实测数据处理结果表明,FHS-SVM比传统超球面SVM(HS-SVM)和超平面SVM(HP-SVM)具有更好的检测性能.

  17. Design of the GaN power amplifier for high gain and ultra-wideband%高增益宽频带GaN功率放大器设计

    Institute of Scientific and Technical Information of China (English)

    张佳浩

    2016-01-01

    针对新一代半导体材料氮化镓(Gallium Nitride,GaN)带宽大、效率高的优点,利用ADS谐波平衡仿真软件,设计了一个1.5~2.5GHz宽带高效的功率放大器。设计采用Cree公司的GaN 高电子迁移率晶体管CGH40010F,利用晶体管的大信号模型进行电路仿真,结果显示,功放在1.5~2.5GHz频带内,饱和输出功率大于41.7dBm,小信号增益大于18dB,功率附加效率大于70%。%This letter designs a 1.5~2.5GHz broadband highly efficient PA using the ADS harmonic-balanced simulator based on GaN,a new semiconductor materials with wide bandwidth and high efficience.The PA was designed with Cree’s GaN HEMT CGH40010F,and simulated with its large signal model.The result shows that the PA had a saturated power above 41.7dBm,a small signal gain over 18dB and the PAE above 74% in 1.5~2.5GHz frequency band.

  18. 基于OFDM调制和Nyquist滤波的超宽通道大容量光传输%Ultra-wideband high-capacity optical transmission based on OFDM modulation and Nyquist filtering

    Institute of Scientific and Technical Information of China (English)

    杨奇; 张晓吟

    2012-01-01

    文章首先概述了产生超宽通道的行业背景,接着介绍了产生超宽通道的两种主要方式;分别阐述了OFDM(正交频分复用)调制方式和Nyquist(奈奎斯特)滤波方式的基本原理和产生途径,分析了这两种方式的优劣特点并进行了比较;最后综述了两种方式的研究现状及今后展望.

  19. Performance characteristics of a conformal ultra-wideband multilayer applicator (CUMLA) for hyperthermia in veterinary patients: a pilot evaluation of its use in the adjuvant treatment of non-resectable tumours.

    Science.gov (United States)

    Smrkovski, O A; Koo, Y; Kazemi, R; Lembcke, L M; Fathy, A; Liu, Q; Phillips, J C

    2013-03-01

    Performance and clinical characteristics of a novel hyperthermia antenna operating at 434 MHz were evaluated for the adjuvant treatment of locally advanced superficial tumours in cats, dogs and horses. Electromagnetic simulations were performed to determine electric field characteristics and compared to simulations for a flat microwave antenna with similar dimensions. Simulation results show a reduced skin surface and backfield irradiation and improved directional irradiation (at broadside) compared to a flat antenna. Radiated power and penetration is notably increased with a penetration depth of 4.59 cm compared to 2.74 cm for the flat antenna. Clinical use of the antenna was then evaluated in six animals with locoregionally advanced solid tumours receiving adjuvant chemotherapy. During clinical applications, therapeutic temperatures were achieved at depths ≥4 cm. Objective responses were seen in all patients; tissue toxicity in one case limited further therapy. This antenna provides compact, efficient, focused and deep-penetrating clinical hyperthermia for the treatment of solid tumours in veterinary patients.

  20. 基于开口椭圆环的高效超宽带极化旋转超表面∗%High-efficiency ultra-wideband p olarization conversion metasurfaces based on split elliptical ring resonators

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Polarization state of electromagnetic waves plays a significant role in the fields of signal transmission and sensitive measurements. High-efficiently manipulating and controlling polarization state by two-dimensional flat metamaterials over a wider bandwidth has been turned into hot issues in recent years. A polarization conversion metasurface based on the split elliptical ring resonator is designed, simulated, and experimentally validated in the microwave regime. The proposed metasurface can convert a linear polarization state into its orthogonal one with a high efficiency for an ultra-wide band. Theoretically, the mechanism of polarization conversion is explained by the theoretical models of high-impedance surface and multi-plasmonic resonances. The metasurface has a strong anisotropy, which behaves as a high-impedance surface, and serves as a metal sheet in orthogonal orientation in the vicinity of the resonant frequencies. The reflection phase has a delay ofπfor one of the two electric field components and remains unchanged for the other. As a result, the polarization angle of the synthesized reflection electric field rotates byπ/2. The fourth-order plasmonic resonances are generated by the electric and magnetic resonances, which contribute to the bandwidth expansion of cross-polarization reflection. Numerically, by means of simulation and analysis on the axial ratio and flare angle of the split elliptical ring resonators, the influences of these structure parameters on the bandwidth and efficiency of the polarization conversion are clarified. And then the design method of multi-peaks and wideband polarization conversion metasurfaces with split elliptic ring resonators is proposed for different kinds of applications. Experimentally, the geometry is implemented within the currently available printing circuit techniques, and a free space method is adopted to measure the scattering coefficients. A polarization conversion ratio of the fabricated sample is larger than 85%at a relative bandwidth of 104.5%, and approximately 100%of the polarization conversion ratio can be achieved around the resonant frequencies. Experimental results are in good consistency with the simulation results. Compared with the anterior polarization conversion metasurfaces, the proposed metasurface broadens the cross-polarization bandwidth greatly with little efficiency expenses. These works provide beneficial guidance for manipulating and controlling polarization states of electromagnetic waves, and have potential applications in modern radar and communication systems, signal detection systems, and sensitivity measurement systems, etc.

  1. Reconfiguration Analysis for Notched Bands Based on Ultra-wideband Antenna%基于超宽带天线的陷波频段可控性分析*

    Institute of Scientific and Technical Information of China (English)

    刘正堂; 程彦杰; 马辉

    2014-01-01

    A novel planar ultra‐wideband antenna with dual band‐notched characteristics is proposed .Two U‐shaped slots are embedded into the radiating patch ,to obtain the notched bands at frequency of 3 .5GHz and 5 .5GHz ,and the cause of notched band is analyzed with the transmission line model theory .Three switches are embedded into the notched slot to reconfigure the notched band .The influence from the states of the switches changed has been analyzed according to equiva‐lent circuits evolving from the transition‐line theory .The measured results show that the UWB antennas have the ability to transition within the four working states which comprise no notched band ,3 .5GHz single notched band ,5 .5GHz single not‐ched band and both notched bands ,providing clear evidence for the achievement of the band‐notched characteristics reconfig‐uration .%设计了一种具有双陷波特性的超宽带单极子天线,在天线中加入两个“U”形缝隙结构,分别在3.3GHz~3.6GHz和5.15GHz~5.825GHz两个频段处产生陷波,并用传输线等效模型对陷波产生的原因进行了分析。在陷波缝隙处加入三个开关结构,对陷波频段进行控制。分析了开关状态的变化对等效电路的影响,对不同开关状态的超宽带天线进行制作并测试。结果表明,天线可以在无陷波、3.5G Hz单一陷波、5.5G Hz单一陷波和双陷波四种工作状态之间进行转换。

  2. JSC interactive basic accounting system

    Science.gov (United States)

    Spitzer, J. F.

    1978-01-01

    Design concepts for an interactive basic accounting system (IBAS) are considered in terms of selecting the design option which provides the best response at the lowest cost. Modeling the IBAS workload and applying this workload to a U1108 EXEC 8 based system using both a simulation model and the real system is discussed.

  3. JSC Wireless Sensor Network Update

    Science.gov (United States)

    Wagner, Robert

    2010-01-01

    Sensor nodes composed of three basic components... radio module: COTS radio module implementing standardized WSN protocol; treated as WSN modem by main board main board: contains application processor (TI MSP430 microcontroller), memory, power supply; responsible for sensor data acquisition, pre-processing, and task scheduling; re-used in every application with growing library of embedded C code sensor card: contains application-specific sensors, data conditioning hardware, and any advanced hardware not built into main board (DSPs, faster A/D, etc.); requires (re-) development for each application.

  4. WAYS TO INCREASE PLASTIC PROPERTIES OF A WIRE IN THE CONDITIONS OF DRAWING OF HARDWARE PRODUCTION OF JSC «BSW MANAGEMENT COMPANY OF HOLDING «ВМС»

    Directory of Open Access Journals (Sweden)

    S. V. Voytenkov

    2015-01-01

    Full Text Available During production of a wire of high groups of durability the problem of ensuring rather high level of ductility is actual. One of options for the prevention of embrittlement of a wire and as, the consequence, increases of plastic properties is use of the device of stabilization of internal tension in a wire. The guidestraightener device improves redistribution of the stretching tension in wire blankets by means of a sign-variable bend. The device of stabilization of internal tension in a wire finds the increasing practical application in the conditions of drawing shop of JSC BSW-management Company of Holding BMC and shows positive results on decrease in number of attacks on reversible twisting.

  5. Isolation of Rhp-PSP, a member of YER057c/YjgF/UK114 protein family with antiviral properties, from the photosynthetic bacterium Rhodopseudomonas palustris strain JSC-3b.

    Science.gov (United States)

    Su, Pin; Feng, Tuizi; Zhou, Xuguo; Zhang, Songbai; Zhang, Yu; Cheng, Ju'e; Luo, Yuanhua; Peng, Jing; Zhang, Zhuo; Lu, Xiangyang; Zhang, Deyong; Liu, Yong

    2015-11-04

    Rhodopseudomonas palustris strain JSC-3b isolated from a water canal adjacent to a vegetable field produces a protein that was purified by bioactivity-guided fractionation based on ammonium sulfate precipitation, ion-exchange absorption and size exclusion. The protein was further identified as an endoribonuclease L-PSP (Liver-Perchloric acid-soluble protein) by shotgun mass spectrometry analysis and gene identification, and it is member of YER057c/YjgF/UK114 protein family. Herein, this protein is designated Rhp-PSP. Rhp-PSP exhibited significant inhibitory activities against tobacco mosaic virus (TMV) in vivo and in vitro. To our knowledge, this represents the first report on the antiviral activity of a protein of the YER057c/YjgF/UK114 family and also the first antiviral protein isolated from R. palustris. Our research provides insight into the potential of photosynthetic bacterial resources in biological control of plant virus diseases and sustainable agriculture.

  6. The Common Time Module, a Robust Time Maintenance System

    Science.gov (United States)

    2009-11-01

    6] S. Meier and H. Weibel , 2007, “IEEE 1588 applied in the environment of high availability LANs,” in Proceedings of the IEEE Symposium on...Time and Time Interval (PTTI) Meeting 44 [7] H. Weibel , “Tutorial on Parallel Redundancy Protocol (PRP),” www.engineering.zhaw.ch. [8] J

  7. A Covert Channel Based on Web Read-time Modulation

    OpenAIRE

    Davis, Joshua

    2014-01-01

    A network covert channel is created that operates by modulating the time between web resource accesses, with an 'average web user' read-time used as a reference. While the covert channel may be classified as timing based, it does not operate by changing deterministic protocol attributes such as inter-packet delay, as do most timing based network covert channels. Instead, our channel communicates by modulating transaction level read-time, which in the web browsing case has significant non-dete...

  8. Vitamin D: Spaceflight, Antarctic, and JSC

    Science.gov (United States)

    Smith, Scott M.; Locke, J.; Zwart, S. R.

    2009-01-01

    Obtaining vitamin D is critical for space travelers because they lack ultraviolet light exposure and have an insufficient dietary supply of vitamin D. Despite the provision of vitamin D supplements to International Space Station (ISS) crewmembers, vitamin D status is consistently lower after flight than before flight, and in several crewmembers has decreased to levels considered clinically significant. Vitamin D has long been known to play a role in calcium metabolism, and more recently its non-calcitropic functions have been recognized. According to the results of several recent studies, functionally relevant measures indicate that the lower limit of serum 25-hydroxyvitamin D (a marker of vitamin D status) should be raised from the current 25 nmol/L to 80 nmol/L. The sub-optimal pre- and postflight vitamin D status is an issue that needs to be addressed, to allow NASA to better define the appropriate amount of supplemental vitamin D to serve as a countermeasure against vitamin D deficiency in astronaut crews. This is very important for long-duration crewmembers, and is critical for exploration-class missions. Ground-based models with limited sunlight exposure could be valuable for evaluating vitamin D supplementation efficacy. One such model is subjects spending the winter in Antarctica, where UV-B radiation levels are zero during the winter. Data from a study of such subjects will enable us to provide long-duration space flight crewmembers with evidence-based recommendations for vitamin D supplementation to achieve optimal vitamin D status before, during, and after flight. We report here results from a vitamin D supplementation study conducted in 2007 in Antarctica at McMurdo Station, and plans for a study to be implemented over the course of 2009. Additionally, in 2008, a study was initiated (and is ongoing) to assess efficacy and safety of supplementing with 2000 IU daily, 10,000 IU weekly, or 50,000 IU weekly for a month and then monthly after that. The data from these studies will enable us to provide space crews with evidence-based recommendations for vitamin D supplementation. The findings also have implications for other persons with limited UV light exposure, including polar workers and the elderly.

  9. JSC Director's Discretionary Fund 1992 Annual Report

    Science.gov (United States)

    Jenkins, Lyle (Compiler)

    1993-01-01

    Annual report of the Johnson Space Center Director's Discretionary Fund documenting effective use of resources. The $1,694,000 funding for FY92 was distributed among 27 projects. The projects are an overall aid to the NASA mission, as well as providing development opportunities for the science and engineering staff with eventual spinoff to commercial uses. Projects described include space-based medical research such as the use of stable isotopes of deuterium and oxygen to measure crew energy use and techniques for noninvasive motion sickness medication. Recycling essentials for space crew support is conducted in the Regenerative Life Support and the Hybrid Regenerative Water Recovery test beds. Two-phase fluid flow simulated under low-gravity conditions, hypervelocity particle impact on open mesh bumpers, and microcalorimetry to measure the long-term hydrazine/material compatibility were investigated. A patent application was made on a shape-memory-alloy release nut. Computer estimate of crew accommodations for advanced concepts was demonstrated. Training techniques were evaluated using multimedia and virtual environment. Upgrades of an electronic still camera provide high resolution images from orbit are presented.

  10. STARDUST Curation and Science at JSC

    Science.gov (United States)

    Nakamura-Messenger, K.; Zolensky, M. E.; Bastien, R.; See, T. H.; Warren, J. L.; Bevill, T. J.; Todd, N.; Fletcher, L.; Horz, F.; Allen, C. C.; Westphal, A. J.; Snead, C.; Ishii, H. A.; Brownlee, D.

    2007-01-01

    Dust particles released from comet 81P/Wild-2 were captured in silica aerogel on-board the STARDUST spacecraft and returned to Earth on January 15, 2006. STARDUST recovered thousands of particles ranging in size from 1 to 100 micrometers. During the six month Preliminary Examination period an international consortium of 180 scientists investigated their mineralogy/petrology, organic/inorganic chemistry, optical properties and isotopic compositions. Stardust samples are now available for research by the entire research community.

  11. JSC Simulations of ADR Technologies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orbital debris in Low Earth Orbit (LEO) is an international problem that threatens the success of all future Low Earth Orbit (LEO) space and exploration...

  12. 基于修正S-V信道模型的多脉冲超宽带系统性能分析%Performance of Ultra Wideband with Multiple Types of Pulses Based on Using Modified S-V Channel Model

    Institute of Scientific and Technical Information of China (English)

    郝润芳; 闫永梅; 王华奎

    2007-01-01

    针对传统超宽带系统发射单种类型脉冲时多址干扰严重的问题,笔者研究了基于修正S-V标准信道模型的多脉冲超宽带系统的功率谱密度和误码率性能.该系统发射信号帧中使用的不是单种类型的脉冲,而是多种不同类型的脉冲,能有效减少多址干扰.理论分析和仿真结果表明,使用多种类型的脉冲可以很好地抑制多址干扰,优化系统性能.

  13. Photonic Techniques for Next-Generation Integrated Optical Networks Based on Ultra-Wideband Radio / Técnicas Fotónicas para Redes Ópticas Integradas de Próxima Generación Basadas en Radio de Banda Ultra Ancha

    OpenAIRE

    Beltrán Ramírez, Marta

    2012-01-01

    La presenta Tesis Doctoral encuentra su ámbito de aplicación en redes de acceso ópticas de fibra hasta el hogar o FTTH (del inglés fibre-to-the-home). Las redes FTTH han sido ampliamente desplegadas en todo el mundo y se prevé que evolucionen hasta arquitecturas de multiplexación por división en longitud de onda o WDM(dle inglés wavelength division multiplexing). Conforme los requerimientos de capacidady ancho de banda por usuario para servicios de comunicación de banda ancha se incrementa...

  14. Protocols for Impulse Radio UWB Ad Hoc Networks

    NARCIS (Netherlands)

    Shi, N.

    2010-01-01

    Ultra Wideband (UWB) technology offers an unprecedented opportunity to further accelerate the evolution of wireless communication and expand the application landscape by enabling outstanding capabilities. UWB radio is fundamentally different from most radio technologies, e.g., Bluetooth, WLAN, etc.

  15. Progress in Development and Applications of Pulsed Power Devices at the University of Texas at Dallas

    Science.gov (United States)

    2005-06-01

    Symposium, Portland, OR, U.S.A., 2005. [6] F. J. Agee, D. W . Scholfield, W . Prather and J. W . Burger, Powerful Ultra-Wide Band Emitters: Status and...Lehr, R.J. Torres, T.C. Tran, J.W. Burger, D.I. Lawry , J.A. Gaudet, “Recent Development in Ultra-Wideband Sources and Antennas,” in Ultra-Wideband

  16. Phase chaos in the dynamics of an ensemble of oscillators with time-modulated global coupling

    Science.gov (United States)

    Kuznetsov, S. P.; Sedova, Yu. V.

    2013-01-01

    The object of consideration is an ensemble of globally coupled self-sustained oscillating elements with a finite-width frequency distribution. The ensemble interacts with the field of a resonator, which is a linear oscillator with a frequency doubly exceeding the mean frequency of the oscillators in the ensemble. The global coupling is switched on and off alternately, so that the ensemble alternatively passes from synchrony to asynchrony (Kuramoto transition). At each stage of activity (synchronization), the field of the resonator causes the mean field of the ensemble to oscillate so that the phase doubles compared with the previous stage of excitation. Therefore, the mean field dynamics is chaotic and, as follows from numerical simulation data, can be associated with the Smale-Williams attractor. Systems of this type can be applied in electronics, specifically, in secure communication systems, noise location, etc.

  17. Multiple symbol differential detection based on sphere decoding for unitary space-time modulation

    Institute of Scientific and Technical Information of China (English)

    LI Ying; WEI JiBo; WANG Xin; YU Quan

    2009-01-01

    Recently, s multiple symbol differential (MSD) sphere decoding (SD) algorithm for unitary spacetime modulation over quasi-static channel has been proved to achieve the performance of maximumlikelihood (ML) detection with relatively low complexity. However, an error floor occurs if the algorithm is applied over rapid-fading channels. Based on the assumption of continuous fading, a multiple symbol differential automatic sphere decoding (MSDASD) algorithm is developed by incorporating a recursive form of an ML metric into automatic SD (ASD) algorithm. Furthermore, two algorithms, termed as MSD approximate ASD (MSDAASD) and MSD pruning ASD (MSDPASD), are proposed to reduce computational complexity and the number of comparisons, respectively. Compared with the existing typical algorithms, i.e., multiple symbol differential feedback detection (MS-DFD) and noncoherent sequence detection (NSD), the performance of the proposed algorithms is much superior to that of MS-DFD and s little inferior to that of NSD, while the complexity is lower than that of MS-DFD in most cases and significantly lower than that of NSD.

  18. The formation of a turbulent front in a time modulated argon APPJ

    Science.gov (United States)

    Zhang, Shiqiang; van Veldhuizen, Eddie; Bruggeman, Peter; Sobota, Ana

    2014-10-01

    Cold atmospheric pressure plasma jets (APPJ) are promising tools for biomedical applications such as wound healing, disinfection, decontamination, and material processing. The jet effluent is blown in an open air environment which leads to air diffusion and argon-air mixtures in the effluent flow. Since the reactive species carried by the flow are important in such kinds of applications, knowledge of the characteristics of the flow are crucial for understanding the distribution, evolution, transport, and chemical reactions of these reactive species. The flow dynamics of an non equilibrium argon-based atmospheric pressure plasma jet (APPJ) is investigated in this work. Shadowgraphy results show that turbulent front appears when the plasma is switched on and off and the laminar length of the flow during the plasma on phase is shorter than that during the plasma off phase. Time resolved gas temperature profiles obtained by Rayleigh scattering are used to explain the formation of the turbulent front when the plasma is switched on and off and the reduction of the length of the laminar flow. The funding is partly from STW.

  19. Novel time-frequency differential space-time modulation for multi-antenna OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Tian Jifeng; Jiang Haining; Song Wentao; Luo Hanwen; Xu Youyun

    2006-01-01

    Differential space-time (DST) modulation has been proposed recently for multiple-antenna systems over Rayleigh fading channels, where neither the transmitter nor the receiver knows the fading coefficients. Among existing schemes, differential modulation is always performed in the time domain and suffers performance degradations in frequency-selective fading channels. In order to combat the fast time and frequency-selective fading, a novel time-frequency differential space-time (TF-DST) modulation scheme, which adopts differential modulation in both time and frequency domains, is proposed for multi-antenna orthogonal frequency division multiplexing (OFDM) system. A corresponding suboptimal yet low-complexity non-coherent detection approach is also proposed. Simulation results demonstrate that the propped system is robust for time and frequency-selective Rayleigh fading channels.

  20. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    NARCIS (Netherlands)

    Balvert, M.; Gorissen, B.L.; den Hertog, D.; Hoffmann, A.L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell

  1. Diagrammatic Explanation of the Reverse Doppler Effect in Space-Time Modulated Photonic Crystals

    CERN Document Server

    Deck-Léger, Zoé-Lise; Caloz, Christophe

    2016-01-01

    An inverse Doppler shift occurs in a photonic crystal (PC) bounded by a moving wall. The interpretation of this result has stirred some controversy. In this paper, we address the problem using a diagrammatic approach. This visual representation provides immediate insight into the phenomenon, and is a powerful tool for the design of time-varying PCs.

  2. The 1989 JSC bibliography of scientific and technical papers

    Science.gov (United States)

    Hutchins, Nancy (Compiler)

    1991-01-01

    This document is a compilation of Lyndon B. Johnson Space Center contributions to the scientific and technical literature in aerospace and life sciences made during calendar year 1989. Citations include NASA formal series reports, journal articles, conference and symposium presentations, papers published in proceedings or other collective works, and seminar and workshop results.

  3. National Space Biomedical Research Institute (NSBRI) JSC Summer Projects

    Science.gov (United States)

    Dowdy, Forrest Ryan

    2014-01-01

    This project optimized the calorie content in a breakfast meal replacement bar for the Advanced Food Technology group. Use of multivariable optimization yielded the highest weight savings possible while simultaneously matching NASA Human Standards nutritional guidelines. The scope of this research included the study of shelf-life indicators such as water activity, moisture content, and texture analysis. Key metrics indicate higher protein content, higher caloric density, and greater mass savings as a result of the reformulation process. The optimization performed for this study demonstrated wide application to other food bars in the Advanced Food Technology portfolio. Recommendations for future work include shelf life studies on bar hardening and overall acceptability data over increased time frames and temperature fluctuation scenarios.

  4. NASA JSC EV2 Intern Spring 2016 - Jennie Chung

    Science.gov (United States)

    Chung, Jennie

    2016-01-01

    Exploration Mission 2 (EM-2) is a mission to resume the manned exploration of the Solar System. This mission is the first crewed mission of NASA’s Orion on the Space Launch System. The target for EM-2 is to perform a flyby of a captured asteroid in lunar orbit, which NASA plans to launch in 2023. As an intern working with EV-2 – Avionics Systems Division in Johnson Space Center, we are developing flight instrumentation systems for EM-2 (MISL & RFID). The Modular Integrated Stackable Layer (MISL) is a compact space-related computer system that is modular, scalable and reconfigurable. The RFID (radio frequency identification) sensors are used to take lower frequency (TC) type measurements and be able to stream data real-time to an RF (radio frequency) interrogator upon demand. Our job, in EV-2, is to certify, test, manufacture/assemble and deliver flight EM-2 DFI System (MISL & RFID). Our goal is to propose a development effort to design low-mass wire and wireless data acquisition and sensor solutions for EM-2 DFI (Development Flight Instrumentation). The team is tasked to provide the most effective use of 75 pounds to acquire DFI data and to collect sensor data for 100-200 high priority DFI channels (mass driven).

  5. JSC Safety and Mission Assurance Data Analysis Overview

    Science.gov (United States)

    Roelant, Henk

    2010-01-01

    These slides describe the data analysis methods that are used to determine inputs for probabilistic risk models supporting the Space Shuttle Program. Other applications can follow a similar path probably using different data sources. Statistical approaches are different and not addressed here. Topics included here: 1) Prior Distribution; 2) Likelihood Data; 3) Bayesian Updating; and 4) Uncertainty and Error. Note: This is a high-level discussion and is not intended to be a tutorial.

  6. Conversion Matrix Analysis of SiGe HBT Gilbert Cell Mixers

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2004-01-01

    The frequency response of SiGe HBT active mixers based on the Gilbert cell topology is analyzed theoretically. The time-varying operation of the Gilbert cell mixer is taken into account by applying conversion matrix analysis. The main bandwidth limiting mechanisms experienced in SiGe HBT Gilbert...... cell mixers performing frequency conversion of ultra-wideband signals is discussed. The analysis is verified by computer simulations using a realistic high-frequency large-signal SiGe HBT model. Design optimization steps towards ultra-wideband operation for Gilbert cell mixers is discussed....

  7. Bidirectional 3.125 Gbps downstream / 2 Gbps upstream impulse radio ultrawide-band (UWB) over combined fiber and wireless link

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Gibbon, Timothy Braidwood; Yu, Xianbin;

    2010-01-01

    We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors.......We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors....

  8. Low Cost Em Signal Spectral Analysis with Two Element Time Modulated Array System by Multiple Signal Classification Algorithms

    Directory of Open Access Journals (Sweden)

    G. Balagurappa,

    2014-03-01

    Full Text Available Today homeland security is a big matter of concern. The present day wireless technology is available to anti-social elements, who are using this in several undesirable manners. By knowing the direction of the source of electromagnetic waves it becomes possible to locate such anti-social groups and take offensive action. In military applications also finding the direction of the signal source becomes very valuable information. The direction finding systems can achieve this goal. Conventional radio direction finding (RDF systems often use an array of two or more antennas and use either phase-comparison or amplitude-comparison of the received signals to determine direction of arrival information. In both of these techniques directional information is derived by processing array data at the receive signal frequency. In this project an alternative approach to direction finding using the concept of a time-switched array is proposed. The time-switched array system uses simple signal processing techniques to provide a directional main beam and pattern nulls at harmonic frequencies. To determine two dimensional angles is three elements, the system cost has been mostly minimised. we now consider the problem of using our low cost system to detect and estimate the direction of arrival of a desired signal in the presence of array antenna. The proposed scheme is cost effective technique in comparison with the existing schemes. MATLAB/GNU OCTAVE simulation tool will be used for simulation. The simulation results, applications, merits and demerits of proposed approach will be analyzed and will be documented.

  9. Control of spontaneous emission of a single quantum emitter through a time-modulated photonic-band-gap environment

    Science.gov (United States)

    Calajò, Giuseppe; Rizzuto, Lucia; Passante, Roberto

    2017-08-01

    We consider the spontaneous emission of a two-level quantum emitter, such as an atom or a quantum dot, in a modulated time-dependent environment with a photonic band gap. An example of such an environment is a dynamical photonic crystal or any other environment with a band gap whose properties are modulated in time, in the effective mass approximation. After introducing our model of a dynamical photonic crystal, we show that it allows new possibilities to control and tailor the physical features of the emitted radiation, specifically its frequency spectrum. In the weak-coupling limit and in an adiabatic case, we obtain the emitted spectrum and we show the appearance of two lateral peaks due to the presence of the modulated environment, separated from the central peak by the modulation frequency. We show that the two side peaks are not symmetric in height, and that their height ratio can be exploited to investigate the density of states of the environment. Our results show that a dynamical environment can give further possibilities to modify the spontaneous emission features, such as its spectrum and emission rate, with respect to a static one. Observability of the phenomena we obtain is discussed, as well as relevance for tailoring and engineering radiative processes.

  10. Mirror deflection control for a confocal scanning laser microscope employing a time-modulated laser and a linear diode array

    Science.gov (United States)

    Aslund, Nils R.; Patwardhan, Ardan; Trepte, Oliver

    1994-04-01

    A mirror deflection device for a CSLM has been developed. It performs repetitive scanning according to a preset waveform which can be chosen arbitrarily. It can also be used to perform stationary positioning at arbitrarily chosen points. A digital memory, comprising dual banks, is used to allow switching from one actuating waveform to another. The movement of the mirror is recorded very accurately. A burst of sequential pulse from a diode laser is deflected by the mirror and recorded by means of a linear diode array. The target pattern is analyzed digitally. The objective is to implement a control strategy whereby a new actuating waveform can be derived in order to correct any deviation between the desired waveform and the recorded one. Some results obtained with the device are reported. Foreseen applications encompass spectral analysis of selected regions and kinetic studies where a trade-off between speed and number of image points is necessary.

  11. Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants

    Directory of Open Access Journals (Sweden)

    Dimos Baltas

    2010-10-01

    Full Text Available Purpose: One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV, then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option.In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices.Material and methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR has been compared to alternative plans with HIPO and free modulation (without MR.All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose (D = were used for treatment plan evaluation and comparison.Results: Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices.In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation restricted clinical plans demonstrated a lower total dwell time by a mean of 1.4% that was proved to be statistically significant (p = 0.002. The HIPO with MR treatment plans produced a higher P+ by 0.5%, which stemmed from a better sparing of the OARs by 1.0%.Conclusions: Both the dosimetric and radiobiological comparison shows that the modulation restricted optimization gives on average similar results with the optimization without modulation restriction in the examined clinical cases. Concluding, based on our results, it appears that the applied dwell time regularization technique is expected to introduce a minor improvement in the effectiveness of the optimized HDR dose distributions.

  12. Comparative Overview of UWB and VLC for Data- Intensive and Security-Sensitive Applications

    DEFF Research Database (Denmark)

    Prasad, Ramjee; Mihovska, Albena D.; Cianca, Ernestina;

    2012-01-01

    This paper provides a comparative overview of two short-range wireless technologies with high potential for use in various data-intensive and security-sensitive applications, namely, ultra wideband (UWB) and visible light communications (VLC). Both are emerging technologies with some unique...

  13. 47 CFR 15.513 - Technical requirements for medical imaging systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Technical requirements for medical imaging... DEVICES Ultra-Wideband Operation § 15.513 Technical requirements for medical imaging systems. (a) The UWB... MHz and 10,600 MHz. (b) Operation under the provisions of this section is limited to medical imaging...

  14. Performance of transmit-reference radio system in frequency-selective fading channels

    NARCIS (Netherlands)

    Wang, Jing; Haartsen, J.C.

    2005-01-01

    Noise-based Transmit-Reference (TR) radio system is a simple and practical candidate for ultra-wideband (UWB) communication applications. This paper evaluates the performance of the Transmit-Reference radio system in a frequency-selective fading channel by theoretical analysis and computer

  15. Performance Assessment of Hybrid Data Fusion and Tracking Algorithms

    DEFF Research Database (Denmark)

    Sand, Stephan; Mensing, Christian; Laaraiedh, Mohamed

    2009-01-01

    This paper presents an overview on the performance of hybrid data fusion and tracking algorithms evaluated in the WHERE consortium. The focus is on three scenarios. For the small scale indoor scenario with ultra wideband (UWB) complementing cellular communication systems, the accuracy can vary in...

  16. The Electro-Optic Beam Position Monitor

    CERN Document Server

    Doherty, James

    2013-01-01

    This reports outlines the development of a new ultra-wideband electro-optic beam position monitor (EO-BPM) for use in the Large Hadron Collider (LHC) which utilises birefringent crystals and the Pockels effect to monitor beam position. The physical principles behind the operation of the device and tested topology, which incorporates two Lithium Tantalate crystals, is discussed.

  17. Weighted near-field focusing in an array-based GPR

    NARCIS (Netherlands)

    Savelyev, T.G.; Yarovoy, A.G.; Ligthart, L.P.

    2008-01-01

    This paper presents a 3-D imaging technique for an ultra-wideband (UWB) ground penetrating radar (GPR) with a single transmit antenna and a linear receive array. The video impulse GPR working in the frequency band of 0.3–3 GHz has been designed in IRCTR for landmine detection, i.e., for a near-field

  18. 76 FR 59391 - Notice of Availability of Government-Owned Inventions; Available for Licensing

    Science.gov (United States)

    2011-09-26

    ... Improving the Efficiency and Reliability of a Broadband Transistor Switch for Periodic Switching... Issued 1/4/2011/ /U.S. Patent No. 7,868,833: An Ultra Wideband Buoyant Cable Antenna Element Issued 1/11..., Alternate Federal Register Liaison Officer. BILLING CODE 3810-FF-P...

  19. A Cross-Layer Approach in Sensing and Resource Allocation for Multimedia Transmission over Cognitive UWB Networks

    NARCIS (Netherlands)

    Aripin, N.M.; Rashid, R.A.; Fisal, N.; Lo, A.C.C.; Ariffin, S.H.S.; Yusof, S.K.S.

    2010-01-01

    We propose an MAC centric cross-layer approach to address the problem of multimedia transmission over cognitive Ultra Wideband (C-UWB) networks. Several fundamental design issues, which are related to application (APP), medium access control (MAC), and physical (PHY) layer, are discussed. Although s

  20. 3D imaging by fast deconvolution algorithm in short-range UWB radar for concealed weapon detection

    NARCIS (Netherlands)

    Savelyev, T.; Yarovoy, A.

    2013-01-01

    A fast imaging algorithm for real-time use in short-range (ultra-wideband) radar with synthetic or real-array aperture is proposed. The reflected field is presented here as a convolution of the target reflectivity and point spread function (PSF) of the imaging system. To obtain a focused 3D image, t

  1. Cutting Edge RFID Technologies for NASA Applications

    Science.gov (United States)

    Fink, Patrick W.

    2007-01-01

    This viewgraph document reviews the use of Radio-frequency identification (RFID) for NASA applications. Some of the uses reviewed are: inventory management in space; potential RFID uses in a remote human outpost; Ultra-Wideband RFID for tracking; Passive, wireless sensors in NASA applications such as Micrometeoroid impact detection and Sensor measurements in environmental facilities; E-textiles for wireless and RFID.

  2. D1.7 -- Intermediate Report on the WHERE2 Channel Model

    DEFF Research Database (Denmark)

    Corre, Yoann; Laaraiedh, Mohamed; Pedersen, Troels

    are considered: the radio access technologies and the environments. As such, investigations with respect to narrowband, wideband and ultra wideband channel characterization in multi-link scenarios are reported. Furthermore, indoor and indoor-to-outdoor environments are considered. The channel variability due...

  3. A Low-Complexity Joint Synchronization and Detection Algorithm for Single-Band DS-CDMA UWB Communications

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.

    2005-01-01

    The problem of asynchronous direct-sequence code division multiple access (DS-CDMA) detection over the ultra-wideband (UWB) multipath channel is considered. A joint synchronization, channel-estimation and multi-user detection scheme based on the adaptive linear minimum mean-square error (LMMSE...

  4. Compressive Sampling for Wireless Communications

    NARCIS (Netherlands)

    Gishkori, S.S.

    2014-01-01

    Wireless communications is undergoing massive development in all forms of its manifestations. In the field of short-range communications, technologies like ultra- wideband (UWB) systems are promising very high data rates, fine timing resolution and coexistence with other physical layer standards. Al

  5. A 0.76-pJ/Pulse 0.1-1 Gpps Microwatt IR-UWB CMOS Pulse Generator with Adaptive PSD Control Using A Limited Monocycle Precharge Technique

    DEFF Research Database (Denmark)

    Shen, Ming; Yin, Ying-Zheng; Jiang, Hao

    2015-01-01

    This brief presents an ultra-wideband pulse generator topology featuring adaptive control of power spectral density for a broad range of applications with different data rate requirements. The adaptivity is accomplished by employing a limited monocycle precharge approach to control the energy use...

  6. GaAs Wideband Low Noise Amplifier Design for Breast Cancer Detection System

    DEFF Research Database (Denmark)

    Yan, Lei; Krozer, Viktor; Delcourt, Sebastien

    2009-01-01

    Modern wideband systems require low-noise receivers with bandwidth approaching 10 GHz. This paper presents ultra-wideband stable low-noise amplifier MMIC with cascode and source follower buffer configuration using GaAs technology. Source degeneration, gate and shunt peaking inductors are used to ...

  7. Optimal One Bit Time Reversal For UWB Impulse Radio In Multi-User Wireless Communications

    DEFF Research Database (Denmark)

    Nguyen, Hung Tuan

    2008-01-01

    In this paper, with the purpose of further reducing the complexity of the system, while keeping its temporal and spatial focusing performance, we investigate the possibility of using optimal one bit time reversal (TR) system for impulse radio ultra wideband multi-user wireless communications...

  8. IEEE802.15.6 -based multi-accelerometer WBAN system for monitoring Parkinson's disease.

    Science.gov (United States)

    Keränen, Niina; Särestöniemi, Mariella; Partala, Juha; Hämäläinen, Matti; Reponen, Jarmo; Seppänen, Tapio; Iinatti, Jari; Jämsä, Timo

    2013-01-01

    In this paper we present a detailed example of a wireless body area network (WBAN) scenario utilizing the recent IEEE802.15.6 standard as applied to a multi-accelerometer system for monitoring Parkinson's disease and fall detection. Ultra wideband physical layer and standard security protocols are applied to meet application requirements for data rate and security.

  9. Low Power Narrow-Band Inductively Source Degenerated LNA in Presence of Substrate Noise

    Directory of Open Access Journals (Sweden)

    Pawan Kumar Singh

    2013-04-01

    Full Text Available This study presents the design and analysis of the inductively source degenerated low noise amplifier for the ultra-wideband application. This technique uses the linearization and the current MOSFET model for calculation of noise figure for the LNA. The impedance, two port network correlation matrix for the parasitic noise component and noise figure is also presented.

  10. FP7-ICT-2009-4 WHERE2 D1.1

    DEFF Research Database (Denmark)

    Holgado, Jose; Nielsen, Jimmy Jessen; Madsen, Tatiana Kozlova

    2011-01-01

    -LTE. It includes relaying and deployment of femto-cells. The short-range system relies either on ZigBee (IEE.802.15.4) or Impulse Radio - Ultra Wideband (e.g. IEEE 802.15.4a). The wireless infrastructure is considered in a given context characterized by the physical environment in which the infrastructure...

  11. Online Estimation of wind turbine blade deflection with UWB signals

    DEFF Research Database (Denmark)

    Jensen, Tobias Lindstrøm; Jakobsen, Morten Lomholt; Østergaard, Jan

    2015-01-01

    In this paper we use ultra-wideband (UWB) signals for the localization of blade tips on wind turbines. Our approach is to acquire two separate distances to each tip via time-delay estimation, and each tip is then localized by triangulation. We derive an approximate maximum a posteriori (MAP) delay...

  12. Time-Reversal for UWB Communications Systems

    Science.gov (United States)

    2005-08-15

    Qiu, A. F. Molisch , “Ultra-wideband Wireless Communications,” Editorial on Special Issue on UWB, IEEE J. Select. Areas Com- mun.,Vol. 24, 2nd Quarter...Optical Fibers,” J. Optical Soc. of Am. Part A, Vol.11, No.12, Dec. 1994. 152. A. Molisch , “Status of Models for UWB Propagation Channel,” IEEE

  13. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  14. UWB planar antenna technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Recent developments of the ultra-wideband(UWB)planar antennas are reviewed,where the progress in UWB plate monopole antennas,UWB printed monopole antennas and the UWB printed slot antennas is introduced and compared.In addition,the UWB printed antennas with the band-notched functions are also presented.

  15. 3D imaging by fast deconvolution algorithm in short-range UWB radar for concealed weapon detection

    NARCIS (Netherlands)

    Savelyev, T.; Yarovoy, A.

    2013-01-01

    A fast imaging algorithm for real-time use in short-range (ultra-wideband) radar with synthetic or real-array aperture is proposed. The reflected field is presented here as a convolution of the target reflectivity and point spread function (PSF) of the imaging system. To obtain a focused 3D image,

  16. Pedestrian effects in indoor UWB off-body communication channels

    NARCIS (Netherlands)

    Ali, A.J.; Scanlon, W.G.; Cotton, S.L.

    2010-01-01

    Ultra-wideband (UWB) technology offers a promising solution for future indoor high-speed, low-power wireless body centric communications. Development and design of such systems requires detailed understanding of the indoor off-body UWB channel, which to date has been scarcely investigated. This pape

  17. Mitigation of wideband interference on UWB-IR transmission using multi-carrier templates

    NARCIS (Netherlands)

    Lakshmanan, M.K.; Nikookar, H.

    2009-01-01

    Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids

  18. A Sub-band Divided Ray Tracing Algorithm Using the DPS Subspace in UWB Indoor Scenarios

    DEFF Research Database (Denmark)

    Gan, Mingming; Xu, Zhinan; Hofer, Markus

    2015-01-01

    Sub-band divided ray tracing (SDRT) is one technique that has been extensively used to obtain the channel characteristics for ultra-wideband (UWB) radio wave propagation in realistic indoor environments. However, the computational complexity of SDRT scales directly with the number of sub-bands. A...

  19. ?Smart COPVs? - Continued Successful Development of JSC IR&D Acoustic Emissions (AE) SHM Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop and apply promising quantitative pass/fail criteria to CPV using acoustic emission (AE) and lay the foundation for continued development of an automated...

  20. Space Weathering in Houston: A Role for the Experimental Impact Laboratory at JSC

    Science.gov (United States)

    Cintala, M. J.; Keller, L. P.; Christoffersen, R.; Hoerz, F.

    2015-01-01

    The effective investigation of space weathering demands an interdisciplinary approach that is at least as diversified as any other in planetary science. Because it is a macroscopic process affecting all bodies in the solar system, impact and its resulting shock effects must be given detailed attention in this regard. Direct observation of the effects of impact is most readily done for the Moon, but it still remains difficult for other bodies in the solar system. Analyses of meteorites and precious returned samples provide clues for space weathering on asteroids, but many deductions arising from those studies must still be considered circumstantial. Theoretical work is also indispensable, but it can only go as far as the sometimes meager data allow. Experimentation, however, can permit near real-time study of myriad processes that could contribute to space weathering. This contribution describes some of the capabilities of the Johnson Space Center's Experimental Impact Laboratory (EIL) and how they might help in understanding the space weathering process.