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Sample records for antennas

  1. Smart antennas

    CERN Document Server

    Godara, Lal Chand

    2004-01-01

    INTRODUCTION Antenna GainPhased Array AntennaPower Pattern Beam Steering Degree of Freedom Optimal AntennaAdaptive AntennaSmart AntennaSummary NARROWBAND PROCESSINGSignal Model Conventional BeamformerNull Steering BeamformerOptimal BeamformerOptimization Using Reference SignalBeam Space Processing Effect of ErrorsNotation and AbbreviationsReferencesADAPTIVE PROCESSINGSample Matrix Inversion AlgorithmUnconstrained Least Mean Squares AlgorithmNormalized Least Mean Squares AlgorithmConstrained

  2. Reconfigurable antenna pattern verification

    Science.gov (United States)

    Drexler, Jerome P. (Inventor); Becker, Robert C. (Inventor); Meyers, David W. (Inventor); Muldoon, Kelly P. (Inventor)

    2013-01-01

    A method of verifying programmable antenna configurations is disclosed. The method comprises selecting a desired antenna configuration from a plurality of antenna configuration patterns, with the selected antenna configuration forming at least one reconfigurable antenna from reconfigurable antenna array elements. The method validates the formation of the selected antenna configuration to determine antenna performance of the at least one reconfigurable antenna.

  3. Reconfigurable antennas

    CERN Document Server

    Bernhard, Jennifer

    2007-01-01

    This lecture explores the emerging area of reconfigurable antennas from basic concepts that provide insight into fundamental design approaches to advanced techniques and examples that offer important new capabilities for next-generation applications. Antennas are necessary and critical components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Making antennas reconfigurable so that their behavior can adapt with changing system requirements or environmental conditions can ameliorate or eliminate these restricti

  4. Antenna toolkit

    CERN Document Server

    Carr, Joseph

    2006-01-01

    Joe Carr has provided radio amateurs and short-wave listeners with the definitive design guide for sending and receiving radio signals with Antenna Toolkit 2nd edition.Together with the powerful suite of CD software, the reader will have a complete solution for constructing or using an antenna - bar the actual hardware! The software provides a simple Windows-based aid to carrying out the design calculations at the heart of successful antenna design. All the user needs to do is select the antenna type and set the frequency - a much more fun and less error prone method than using a con

  5. Notch Antennas

    Science.gov (United States)

    Lee, Richard Q.

    2004-01-01

    Notch antennas, also known as the tapered slot antenna (TSA), have been the topics of research for decades. TSA has demonstrated multi-octave bandwidth, moderate gain (7 to 10 dB), and symmetric E- and H- plane beam patterns and can be used for many different applications. This chapter summarizes the research activities on notch antennas over the past decade with emphasis on their most recent advances and applications. This chapter begins with some discussions on the designs of single TSA; then follows with detailed discussions of issues associated with TSA designs and performance characteristics. To conclude the chapter, some recent developments in TSA arrays and their applications are highlighted.

  6. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  7. Superluminal antenna

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, John; Earley, Lawrence M.; Krawczyk, Frank L.; Potter, James M.; Romero, William P.; Wang, Zhi-Fu

    2017-03-28

    A superluminal antenna element integrates a balun element to better impedance match an input cable or waveguide to a dielectric radiator element, thus preventing stray reflections and consequent undesirable radiation. For example, a dielectric housing material can be used that has a cutout area. A cable can extend into the cutout area. A triangular conductor can function as an impedance transition. An additional cylindrical element functions as a sleeve balun to better impedance match the radiator element to the cable.

  8. 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.

  9. Optical antennas and plasmonics

    OpenAIRE

    Park, Q-Han

    2009-01-01

    Optical antenna is a nanoscale miniaturization of radio or microwave antennas that is also governed by the rule of plasmonics. We introduce various types of optical antenna and make an overview of recent developments in optical antenna research. The role of local and surface plasmons in optical antenna is explained through antenna resonance and resonance conditions for specific metal structures are explicitly obtained. Strong electric field is shown to exist within a highly localized region o...

  10. Antennas in inhomogeneous media

    CERN Document Server

    Galejs, Janis; Fock, V A; Wait, J R

    2013-01-01

    Antennas in Inhomogeneous Media details the methods of analyzing antennas in such inhomogeneous media. The title covers the complex geometrical configurations along with its variational formulations. The coverage of the text includes various conditions the antennas are subjected to, such as antennas in the interface between two media; antennas in compressible isotropic plasma; and linear antennas in a magnetoionic medium. The selection also covers insulated loops in lossy media; slot antennas with a stratified dielectric or isotropic plasma layers; and cavity-backed slot antennas. The book wil

  11. Optical antenna gain. I - Transmitting antennas

    Science.gov (United States)

    Klein, B. J.; Degnan, J. J.

    1974-01-01

    The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.

  12. Optical antenna gain. 1: transmitting antennas.

    Science.gov (United States)

    Klein, B J; Degnan, J J

    1974-09-01

    The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM(00) mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.

  13. Flexible plasma linear antenna

    Science.gov (United States)

    Zhao, Jiansen; Wang, Shengzheng; Wu, Huafeng; Liu, Yue; Chang, Yongmeng; Chen, Xinqiang

    2017-02-01

    In this work, we introduce a type of plasma antenna that was fabricated using flexible materials and excited using a 5-20 kHz alternating current (ac) power supply. The results showed that the antenna characteristics, including the impedance, the reflection coefficient (S11), the radiation pattern, and the gain, can be controlled rapidly and easily by varying both the discharge parameters and the antenna shapes. The scope for reconfiguration is greatly enhanced when the antenna shape is changed from a monopole to a helix configuration. Additionally, the antenna polarization can also be adjusted by varying the antenna shapes.

  14. Antenna Structure Registrate

    Data.gov (United States)

    Department of Homeland Security — This file is an extract of the Antenna Structure Registrate (ASR). The ASR consists of antenna structures that are more than 60.96 meters (200 feet) in height or...

  15. Antenna Pattern Range (APR)

    Data.gov (United States)

    Federal Laboratory Consortium — TheAntenna Pattern Range (APR)features a non-metallic arch with a trolley to move the transmit antenna from the horizon to zenith. At the center of the ground plane,...

  16. Cross Resonant Optical Antenna

    Science.gov (United States)

    Biagioni, P.; Huang, J. S.; Duò, L.; Finazzi, M.; Hecht, B.

    2009-06-01

    We propose a novel cross resonant optical antenna consisting of two perpendicular nanosized gold dipole antennas with a common feed gap. We demonstrate that the cross antenna is able to convert propagating fields of any polarization state into correspondingly polarized, localized, and enhanced fields and vice versa. The cross antenna structure therefore opens the road towards the control of light-matter interactions based on polarized light as well as the analysis of polarized fields on the nanometer scale.

  17. Cross resonant optical antenna.

    Science.gov (United States)

    Biagioni, P; Huang, J S; Duò, L; Finazzi, M; Hecht, B

    2009-06-26

    We propose a novel cross resonant optical antenna consisting of two perpendicular nanosized gold dipole antennas with a common feed gap. We demonstrate that the cross antenna is able to convert propagating fields of any polarization state into correspondingly polarized, localized, and enhanced fields and vice versa. The cross antenna structure therefore opens the road towards the control of light-matter interactions based on polarized light as well as the analysis of polarized fields on the nanometer scale.

  18. Coherently combining antennas

    Science.gov (United States)

    Dybdal, Robert B. (Inventor); Curry, Samuel J. (Inventor)

    2009-01-01

    An apparatus includes antenna elements configured to receive a signal including pseudo-random code, and electronics configured to use the pseudo-random code to determine time delays of signals incident upon the antenna elements and to compensate the signals to coherently combine the antenna elements.

  19. Dielectrically Loaded Biconical Antennas

    Science.gov (United States)

    Nusseibeh, Fouad Ahmed

    1995-01-01

    Biconical antennas are of great interest to those who deal with broadband applications including the transmission/reception of pulses. In particular, wide-angle conical antennas are an attractive choice in many applications including Electronic Support Measures (ESM) and the measurements of transient surface currents and charge densities on aircraft. Dielectric loading in the interior region of a conical antenna can be used to reduce the size of the antenna especially at low frequencies and/or for structural strength. Therefore, having an analytical solution for the input impedance and the frequency response is very helpful in optimizing the design and understanding the behavior of the antenna. From the quasi-analytical solution for the input impedance and the electric field of a wide-angle conical antenna, it can be seen that the dielectric loading in the antenna region improves the input impedance at low frequencies, but increases the number of resonance points and the magnitude of these peaks. When an inhomogeneous dielectric load is used, the magnitude of the resonance peaks is decreased (depending on the way the load is distributed), improving the input impedance of the antenna significantly. Introducing a dielectric load in the interior region of an electrically short receiving cone makes the antenna behave as an electrically longer antenna. However, this is not true for the case for electrical1y long antennas. For the case of pulse transmission, the dielectric load affects only the amplitude. Of course, if the dielectric fills the whole space, both transmitting and receiving antennas behave as electrically longer antennas.

  20. Microstrip antennas in subsurface sensing

    Science.gov (United States)

    Volgyi, Ferenc

    2000-07-01

    This paper reviews the various applications of microstrip antennas with special emphasis on subsurface sensing, microwave moisture measurement and nondestructive testing of dielectric materials. With reference to the literature, we first describe the commonly used GPR-antennas, the printed Vivaldi-antennas, and microstrip antennas used in moisture content measurement. Furthermore, attention is given to the problems of new antenna technologies, showing examples for active integrated antennas, a photonic band gap patch antenna and a silicon micromachined patch antenna. The reminder of the paper summarizes relevant R&D activities in microstrip antennas at BUTE/DMT, focusing on near-field experiments, monitoring of particleboards and WLAN- applications of patch radiators.

  1. Multifunctional Antenna Techniques

    Science.gov (United States)

    2015-11-25

    accelerating the development of more advanced and compact radiating systems. Fig. 1 Stripline-fed spiral antenna: (top) cross-section of the stripline...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Multifunctional antennas, reconfigurable antennas, electromagnetics REPORT... Electromagnetic Analysis and Applications, (06 2013): 223. doi: 10.4236/jemaa.2013.55036 Teng-Kai Chen, Gregory H. Huff. Transmission line analysis

  2. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  3. Antenna applications of superconductors

    Science.gov (United States)

    Hansen, R. C.

    1991-09-01

    The applicability of superconductors to antennas is examined. Potential implementations that are examined are superdirective arrays; electrically small antennas; tuning and matching of these two; high-gain millimeter-wavelength arrays; and kinetic inductance slow wave structures for array phasers and traveling wave array feeds. It is thought that superdirective arrays and small antennas will not benefit directly, but their tuning/matching networks will undergo major improvements. Miniaturization of antennas will not be aided, but much higher gain millimeter-wave arrays will be realizable. Kinetic inductance slow-wave lines appear advantageous for improved array phasers and time delay, as well as for traveling-wave array feeds.

  4. MASTER TELEVISION ANTENNA SYSTEM.

    Science.gov (United States)

    Rhode Island State Dept. of Education, Providence.

    SPECIFICATIONS FOR THE FURNISHING AND INSTALLATION OF TELEVISION MASTER ANTENNA SYSTEMS FOR SECONDARY AND ELEMENTARY SCHOOLS ARE GIVEN. CONTRACTOR REQUIREMENTS, EQUIPMENT, PERFORMANCE STANDARDS, AND FUNCTIONS ARE DESCRIBED. (MS)

  5. Substrate integrated antennas and arrays

    CERN Document Server

    Cheng, Yu Jian

    2015-01-01

    Substrate Integrated Antennas and Arrays provides a single source for cutting-edge information on substrate integrated circuits (SICs), substrate integrated waveguide (SIW) feeding networks, SIW slot array antennas, SIC traveling-wave antennas, SIW feeding antennas, SIW monopulse antennas, and SIW multibeam antennas. Inspired by the author's extensive research, this comprehensive book:Describes a revolutionary SIC-based antenna technique with the potential to replace existing antenna technologiesExamines theoretical and experimental results connected to electrical and mechanical performanceExp

  6. Experiments with Dipole Antennas

    Science.gov (United States)

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a…

  7. MEMS Tunable Antennas

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund

    2014-01-01

    Addressing low frequency bands is challenging on small platforms. Tunability is a promising solution to cover the bandwidth required for 4G mobile communication. The work presents two designs and shows that for comparable efficiency and bandwidth, the tunable antenna occupies half the volume...... required by the wide-band antenna....

  8. Milestones in Broadcasting: Antennas.

    Science.gov (United States)

    Media in Education and Development, 1985

    1985-01-01

    Briefly describes the development of antennas in the prebroadcast era (elevated antenna, selectivity to prevent interference between stations, birth of diplex, directional properties, support structures), as well as technological developments used in long-, medium-, and short-wave broadcasting, VHF/FM and television broadcasting, and satellite…

  9. ANTENNA OF RADIO CONTROL

    Directory of Open Access Journals (Sweden)

    Ludwig Ilnytskyi

    2015-12-01

    Full Text Available The article is devoted to current issues in the field of radio monitoring. In this article was considered the antenna of radio control, which represents a grid from three vibrators. Threelement antenna array provides simultaneous control of two radio electronic devices that radiates at frequencies that are close to each other. Antenna system using simple technical means provides noise suppression, even if noise will have the same frequency as useful signal. This makes it possible to use the antenna system in conditions of multibeam wave propagation under the adjustment on the most intense by the power beam. Antenna system makes it possible to measure the electromagnetic field intensity, congestion of the frequency spectrum, direction of noise electromagnetic waves incidence, noise electric field intensity.

  10. Handbook of antenna technologies

    CERN Document Server

    Liu, Duixian; Nakano, Hisamatsu; Qing, Xianming; Zwick, Thomas

    2016-01-01

    The Handbook of Antenna Technologies aims to present the rapid development of antenna technologies, particularly in the past two decades, and also showcasing the newly developed technologies and the latest applications. The handbook will provide readers with the comprehensive updated reference information covering theory, modeling and optimization methods, design and measurement, new electromagnetic materials, and applications of antennas. The handbook will widely cover not only all key antenna design issues but also fundamentals, issues related to antennas (transmission, propagation, feeding structure, materials, fabrication, measurement, system, and unique design challenges in specific applications). This handbook will benefit the readers as a full and quick technical reference with a high-level historic review of technology, detailed technical descriptions and the latest practical applications.

  11. RF MEMS Based Reconfigurable Antennas

    Science.gov (United States)

    Simons, Rainee N.

    2004-01-01

    The presentation will first of all address the advantages of RF MEMS circuit in antenna applications and also the need for electronically reconfigurable antennas. Next, discuss some of the recent examples of RF MEMS based reconfigurable microstrip antennas. Finally, conclude the talk with a summary of MEMS antenna performance.

  12. Optimisation of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    H. El Hamchary

    1996-04-01

    Full Text Available When choosing the most appropriate microstrip antenna configuration for particular applications, the kind of excitation of the radiating element is an essential factor that requires careful considerations. For controlling the distribution of energy of the linear or planar array of elements and for coupling energy to the individual elements, a wide variety of feed mechanisms are available. In this paper, the coaxial antenna feeding is assumed and the best (optimised feeding is found. Then, antenna characteristics such as radiation pattern, return loss, input impedance, and VSWR are obtained.

  13. Antennas from theory to practice

    CERN Document Server

    Huang, Yi

    2008-01-01

    Practical, concise and complete reference for the basics of modern antenna design Antennas: from Theory to Practice discusses the basics of modern antenna design and theory. Developed specifically for engineers and designers who work with radio communications, radar and RF engineering, this book offers practical and hands-on treatment of antenna theory and techniques, and provides its readers the skills to analyse, design and measure various antennas. Key features: Provides thorough coverage on the basics of transmission lines, radio waves and propag

  14. Dielectric Covered Planar Antennas

    Science.gov (United States)

    Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

    2014-01-01

    An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

  15. Nonlinear plasmonic antennas

    Directory of Open Access Journals (Sweden)

    Shakeeb Bin Hasan

    2014-12-01

    Full Text Available Contrary to traditional optical elements, plasmonic antennas made from nanostructured metals permit the localization of electromagnetic fields on length scales much smaller than the wavelength of light. This results in huge amplitudes for the electromagnetic field close to the antenna being conducive for the observation of nonlinear effects already at moderate pump powers. Thus, these antennas exhibit a promising potential to achieve optical frequency conversion and all-optical control of light at the nano-scale. This opens unprecedented opportunities for ultrafast nonlinear spectroscopy, sensing devices, on-chip optical frequency conversion, nonlinear optical metamaterials, and novel photon sources. Here, we review some of the recent advances in exploiting the potential of plasmonic antennas to realize robust nonlinear applications.

  16. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  17. Electrically driven optical antennas

    Science.gov (United States)

    Kern, Johannes; Kullock, René; Prangsma, Jord; Emmerling, Monika; Kamp, Martin; Hecht, Bert

    2015-09-01

    Unlike radiowave antennas, so far optical nanoantennas cannot be fed by electrical generators. Instead, they are driven by light or indirectly via excited discrete states in active materials in their vicinity. Here we demonstrate the direct electrical driving of an in-plane optical antenna by the broadband quantum-shot noise of electrons tunnelling across its feed gap. The spectrum of the emitted photons is determined by the antenna geometry and can be tuned via the applied voltage. Moreover, the direction and polarization of the light emission are controlled by the antenna resonance, which also improves the external quantum efficiency by up to two orders of magnitude. The one-material planar design offers facile integration of electrical and optical circuits and thus represents a new paradigm for interfacing electrons and photons at the nanometre scale, for example for on-chip wireless communication and highly configurable electrically driven subwavelength photon sources.

  18. Array Antenna Limitations

    CERN Document Server

    Jonsson, B L G; Hussain, N

    2013-01-01

    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  19. Optical antenna gain. II - Receiving antennas

    Science.gov (United States)

    Degnan, J. J.; Klein, B. J.

    1974-01-01

    Expressions are developed for the gain of a centrally obscured, circular optical antenna used as the collecting and focusing optics in a laser receiver, involving losses due to (1) incoming light blockage by central obscuration, (2) energy spillover at the detector, and (3) the effect of local oscillator distribution in the case of heterodyne or homodyne detection. Numerical results are presented for direct detection and for three types of local oscillator distribution (uniform, Gaussian, and matched).

  20. Electrochemically Programmable Plasmonic Antennas.

    Science.gov (United States)

    Dong, Shi; Zhang, Kai; Yu, Zhiping; Fan, Jonathan A

    2016-07-26

    Plasmonic antennas are building blocks in advanced nano-optical systems due to their ability to tailor optical response based on their geometry. We propose an electrochemical approach to program the optical properties of dipole antennas in a scalable, fast, and energy-efficient manner. These antennas comprise two arms, one serving as an anode and the other a cathode, separated by a solid electrolyte. As a voltage is applied between the antenna arms, a conductive filament either grows or dissolves within the electrolyte, modifying the antenna load. We probe the dynamics of stochastic filament formation and their effects on plasmonic mode programming using a combination of three-dimensional optical and electronic simulations. In particular, we identify device operation regimes in which the charge-transfer plasmon mode can be programmed to be "on" or "off." We also identify, unexpectedly, a strong correlation between DC filament resistance and charge-transfer plasmon mode frequency that is insensitive to the detailed filament morphology. We envision that the scalability of our electrochemical platform can generalize to large-area reconfigurable metamaterials and metasurfaces for on-chip and free-space applications.

  1. Cup Cylindrical Waveguide Antenna

    Science.gov (United States)

    Acosta, Roberto J.; Darby, William G.; Kory, Carol L.; Lambert, Kevin M.; Breen, Daniel P.

    2008-01-01

    The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).

  2. 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.

  3. The ACTS multibeam antenna

    Science.gov (United States)

    Regier, Frank A.

    1992-01-01

    The Advanced Communications Technology Satellite (ACTS) to be launched in 1993 is briefly introduced. Its multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems, both utilizing orthogonal polarizations, is described. Dual polarization is achieved by using one feed assembly for each polarization in conjunction with nested front and back subreflectors, the gridded front subreflector acting as a window for one polarization and a reflector for the other. The antennas produce spot beams with approximately 0.3 degree beamwidth and gains of approximately 50 dbi. High surface accuracy and high edge taper produce low sidelobe levels and high cross-polarization isolation. A brief description is given of several Ka-band components fabricated for ACTS. These include multiflare antenna feedhorns, beam-forming networks utilizing latching ferrite waveguide switches, a 30 GHz HEMT low-noise amplifier and a 20 GHz TWT power amplifier.

  4. The ACTS multibeam antenna

    Science.gov (United States)

    Regier, Frank A.

    1992-06-01

    The Advanced Communications Technology Satellite (ACTS) to be launched in 1993 is briefly introduced. Its multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems, both utilizing orthogonal polarizations, is described. Dual polarization is achieved by using one feed assembly for each polarization in conjunction with nested front and back subreflectors, the gridded front subreflector acting as a window for one polarization and a reflector for the other. The antennas produce spot beams with approximately 0.3 degree beamwidth and gains of approximately 50 dbi. High surface accuracy and high edge taper produce low sidelobe levels and high cross-polarization isolation. A brief description is given of several Ka-band components fabricated for ACTS. These include multiflare antenna feedhorns, beam-forming networks utilizing latching ferrite waveguide switches, a 30 GHz HEMT low-noise amplifier and a 20 GHz TWT power amplifier.

  5. Backfire antennas with dipole elements

    DEFF Research Database (Denmark)

    Nielsen, Erik Dragø; Pontoppidan, Knud

    1970-01-01

    A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...... the surface current distribution on the reflector plate. Numerical results obtained for Yagi backfire antennas and short-backfire antennas using this theory are compared with experimental results....

  6. Printed MIMO antenna engineering

    CERN Document Server

    Sharawi, Mohammad S

    2014-01-01

    Wireless communications has made a huge leap during the past two decades. The multiple-input-multiple-output (MIMO) technology was proposed in the 1990's as a viable solution that can overcome the data rate limit experienced by single-input-single-output (SISO) systems. This resource is focused on printed MIMO antenna system design. Printed antennas are widely used in mobile and handheld terminals due to their conformity with the device, low cost, good integration within the device elements and mechanical parts, as well as ease of fabrication.A perfect design companion for practicing engineers

  7. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...... cylindrical surfaces have the sane characteristic constants and different constants are treated separately. Extensive numerical computations of the field radiated from the slot antennas described here are being carried out, but no numerical results are yet available...

  8. Hyperbolic thermal antenna

    CERN Document Server

    Barbillon, Grégory; Biehs, Svend-Age; Ben-Abdallah, Philippe

    2016-01-01

    A thermal antenna is an electromagnetic source which emits in its surrounding, a spatially coherent field in the infrared frequency range. Usually, its emission pattern changes with the wavelength so that the heat flux it radiates is weakly directive. Here, we show that a class of hyperbolic materials, possesses a Brewster angle which is weakly dependent on the wavelength, so that they can radiate like a true thermal antenna with a highly directional heat flux. The realization of these sources could open a new avenue in the field of thermal management in far-field regime.

  9. Antennas fundamentals, design, measurement

    CERN Document Server

    Long, Maurice

    2009-01-01

    This comprehensive revision (3rd Edition) is a senior undergraduate or first-year graduate level textbook on antenna fundamentals, design, performance analysis, and measurements. In addition to its use as a formal course textbook, the book's pragmatic style and emphasis on the fundamentals make it especially useful to engineering professionals who need to grasp the essence of the subject quickly but without being mired in unnecessary detail. This new edition was prepared for a first year graduate course at Southern Polytechnic State University in Georgia. It provides broad coverage of antenna

  10. Aperture optical antennas

    CERN Document Server

    Wenger, Jerome

    2014-01-01

    This contribution reviews the studies on subwavelength aperture antennas in the optical regime, paying attention to both the fundamental investigations and the applications. Section 2 reports on the enhancement of light-matter interaction using three main types of aperture antennas: single subwavelength aperture, single aperture surrounded by shallow surface corrugations, and subwavelength aperture arrays. A large fraction of nanoaperture applications is devoted to the field of biophotonics to improve molecular sensing, which are reviewed in Section 3. Lastly, the applications towards nano-optics (sources, detectors and filters) are discussed in Section 4.

  11. Wireless Distributed Antenna MIMO

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception...... of radio-frequency signals, an optical transmitter in the form of an electro-optic conversion unit for each of said plurality of antenna units, each electro-optic conversion unit adapted for converting an RF signal into an optical signal, a plurality of a single core optical fibers for guiding the optical...

  12. Non-standard antennas

    CERN Document Server

    Le Chevalier, Francois; Staraj, Robert

    2013-01-01

    This book aims at describing the wide variety of new technologies and concepts of non-standard antenna systems - reconfigurable, integrated, terahertz, deformable, ultra-wideband, using metamaterials, or MEMS,  etc, and how they open the way to a wide range of applications, from personal security and communications to multifunction radars and towed sonars, or satellite navigation systems, with space-time diversity on transmit and receive. A reference book for designers  in this lively scientific community linking antenna experts and signal processing engineers.

  13. China's Largest Radio Antenna System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ After three-and-half-year efforts, the National Astronomical Observatories at CAS (NAOC) has constructed two arrays of radio antennae: a 50m antenna at Miyun Station in Beijing and a 40m antenna in Kunming, capital of southwest China's Yunnan Province.

  14. Validation of Emulated Omnidirectional Antenna Output Using Directive Antenna Data

    DEFF Research Database (Denmark)

    Hejselbæk, Johannes; Karstensen, Anders; Nielsen, Jesper Ødum

    2016-01-01

    In this paper, we present validation of a method for constructing a virtual omnidirectional antenna in the azimuth plane. The virtual omnidirectional antenna utilizes a combination of data from directive horn antennas. The aim is to utilize the high gain of the horn antenna to improve the dynamic...... range of channel sounding measurements conducted in the centimeter and millimeter wave bands. The resulting complex impulse response from the virtual omnidirectional antenna is used to find the power-delay-profile (PDP). This is then compared to measurements conducted at the same time using a real...... omnidirectional antenna. The validation shows that the synthesized omnidirectional is capable of predicting main components and the slope of the PDP. Further, it is shown that by choosing angular sampling steps corresponding to the half power beam width (HPBW) of the used antenna similar power levels can...

  15. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase...

  16. Community Antenna Television (CATV).

    Science.gov (United States)

    Federal Communications Commission, Washington, DC.

    The number of households hooked up to cable television or community antenna television (CATV) is expanding rapidly, and Federal Communications Commission (FCC) has been developing regulations since 1962 to guide the growth of the industry. By 1965 the FCC had claimed jurisdiction over all CATV systems in the U. S. This jurisdiction was challenged…

  17. Antenna theory analysis and design

    CERN Document Server

    Balanis, Constantine A

    2005-01-01

    The discipline of antenna theory has experienced vast technological changes. In response, Constantine Balanis has updated his classic text, Antenna Theory, offering the most recent look at all the necessary topics. New material includes smart antennas and fractal antennas, along with the latest applications in wireless communications. Multimedia material on an accompanying CD presents PowerPoint viewgraphs of lecture notes, interactive review questions, Java animations and applets, and MATLAB features. Like the previous editions, Antenna Theory, Third Edition meets the needs of e

  18. Quartz antenna with hollow conductor

    Science.gov (United States)

    Leung, Ka-Ngo; Benabou, Elie

    2002-01-01

    A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

  19. Evolutionary optimization of optical antennas

    CERN Document Server

    Feichtner, Thorsten; Kiunke, Markus; Hecht, Bert

    2012-01-01

    The design of nano-antennas is so far mainly inspired by radio-frequency technology. However, material properties and experimental settings need to be reconsidered at optical frequencies, which entails the need for alternative optimal antenna designs. Here a checkerboard-type, initially random array of gold cubes is subjected to evolutionary optimization. To illustrate the power of the approach we demonstrate that by optimizing the near-field intensity enhancement the evolutionary algorithm finds a new antenna geometry, essentially a split-ring/two-wire antenna hybrid which surpasses by far the performance of a conventional gap antenna by shifting the n=1 split-ring resonance into the optical regime.

  20. Integrated Solar Panel Antennas for Cube Satellites

    OpenAIRE

    Mahmoud, Mahmoud N.

    2010-01-01

    This thesis work presents an innovative solution for small satellite antennas by integrating slot antennas and solar cells on the same panel to save small satellite surface real estate and to replace deployed wire antennas for certain operational frequencies. The two main advantages of the proposed antenna are: 1) the antenna does not require an expensive deployment mechanism that is required by dipole antennas; 2) the antenna does not occupy as much valuable surface real estate as patch ante...

  1. A Reconfigurable Radiation Pattern Annular Slot Antenna

    OpenAIRE

    Aziz, NA; Radhi, A; Nilavalan, R

    2016-01-01

    This paper contemplate a theoretical analysis of a pattern reconfigurable antenna using annular slot antenna operating in low frequency. A shorting pin is inserted to allow the annular slot antenna to have an omnidirectional radiation pattern like a monopole antenna. The reconfigurable antenna consists of numerous metal cylinders arranged around the annular slot antenna. By controlling pin diodes associated with the metal cylinders, the antenna is capable of working up in different dire...

  2. 47 CFR 80.863 - Antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna system. 80.863 Section 80.863... Antenna system. (a) An antenna system must be installed which is as nondirectional and as efficient as is... construction of the required antenna must insure operation in time of emergency. (b) If the required antenna...

  3. 47 CFR 80.866 - Spare antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Spare antenna. 80.866 Section 80.866... Spare antenna. A spare transmitting antenna completely assembled for immediate erection must be provided. If the installed transmitting antenna is suspended between supports, this spare antenna must be...

  4. Circuit realization microwave antennas-oscillator on strip antennas

    OpenAIRE

    Golynskyy, V. D.; Prudyus, I. N.

    2009-01-01

    Showing special feature of development circuitries microwave transistors antennasoscillator on strip dielectric-resonator-antennas. Showing circuitries and technical characteristics of developed microwave antennasoscillator on strip.

  5. Miniaturization of Spherical Magnetodielectric Antennas

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle

    The fundamental limitations in performance of electrically small antennas (ESAs) - and how far these may be approached - have been of great interest for over a century. Particularly over the past few decades, it has become increasingly relevant and important, to approach these limits in view...... to the important antenna parameters of radiation efficiency e and impedance bandwidth. For single-mode antennas the fundamental minimum Q is the Chu lower bound. In this Ph.D. dissertation, the topic is miniaturization of spherical antennas loaded by an internal magnetodielectric core. The goal is to determine......, quantify, and assess the effects of an internal material loading upon antenna performance, including its potentials towards miniaturization. Emphasis have been upon performing an exhaustive and exact analysis of rigorous validity covering a large class of spherical antennas. In the context of this study...

  6. A Compact UWB Diversity Antenna

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2014-01-01

    Full Text Available A compact printed ultrawideband (UWB diversity antenna with a size of 30 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz is proposed. The antenna is composed of two semielliptical monopoles fed by two microstrip lines. Two semicircular slots, two rectangular slots, and one stub are introduced in the ground plane to adjust the impedance bandwidth of the antenna and improve the isolation between two feeding ports. The simulated and measured results show that impedance bandwidth of the proposed antenna can cover the whole UWB band with a good isolation of < −15 dB. The radiation patterns, peak antenna gain, and envelope correlation coefficient are also measured and discussed. The measured results show that the proposed antenna can be a good candidate for some portable MIMO/diversity UWB applications.

  7. Antenna structure with distributed strip

    Science.gov (United States)

    Rodenbeck, Christopher T.

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  8. Antenna for Ultrawideband Channel Sounding

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Pedersen, Gert F.

    2016-01-01

    A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact...... on the antenna performance. The optimized antenna demonstrates S11 below -10 dB and a stable omnidirectional radiation pattern robust against the cable effect over the frequency band 1.5-41 GHz despite its compactness (the maximum electrical dimension is of 0.29max, where max is the free space wavelength...... at the lowest frequency of operation). A prototype of the antenna is fabricated and tested. The simulated and measured S11 are in a good agreement. Measured radiation patterns confirm the pattern stability in terms of the direction of maximum radiation and 3 dB beamwidth....

  9. Antenna Calibration and Measurement Equipment

    Science.gov (United States)

    Rochblatt, David J.; Cortes, Manuel Vazquez

    2012-01-01

    A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

  10. A distributed array antenna system

    Science.gov (United States)

    Shaw, R.; Kovitz, J.

    1986-01-01

    The Space Station communication system will use microwave frequency radio links to carry digitized information from sender to receiver. The ability of the antenna system to meet stringent requirements on coverage zones, multiple users, and reliability will play an important part in the overall multiple access communication system. This paper will describe the configuration of a multibeam conformal phased array antenna and the individual microwave integrated components incoporated into this antenna system.

  11. Optical antenna gain. 2: receiving antennas.

    Science.gov (United States)

    Degnan, J J; Klein, B J

    1974-10-01

    Expressions are derived for the gain of a centrally obscured, circular optical antenna when used as the collecting and focusing optics in a laser receiver which include losses due to (1) blockage of the incoming light by the central obscuration, (2) the spillover of energy at the detector, and (3) the effect of local oscillator distribution in the case of heterodyne or homodyne detection. Numerical results are presented for direct detection and for three types of local oscillator distributions (uniform, Gaussian, and matched) in the case of heterodyne or homodyne detection. The results are presented in several graphs that allow the rapid evaluation of receiver gain for an arbitrary set of telescope and detector parameters. It is found that, for uniform illumination by the LO, the optimum SNR is obtained when the detector radius is approximately 0.74 times the Airy disk radius. The use of an optimized Gaussian (spot size = 0.46 times the Airy disk radius) improves the receiver gain by less than 1 dB. Theuse results are insensitive to the size of the central obscuration.

  12. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  13. Spiral Microstrip Antenna with Resistance

    Science.gov (United States)

    Shively, David G. (Inventor)

    1998-01-01

    A spiral microstrip antenna having resistor elements embedded in each of the spiral arms is provided. The antenna is constructed using a conductive back plane as a base. The back plane supports a dielectric slab having a thickness between one-sixteenth and one-quarter of an inch. A square spiral, having either two or four arms, is attached to the dielectric slab. Each arm of the spiral has resistor elements thereby dissipating an excess energy not already emitted through radiation. The entire configuration provides a thin, flat, high gain, wide bandwidth antenna which requires no underlying cavity. The configuration allows the antenna to be mounted conformably on an aircraft surface.

  14. Small Antennas for Wireless Micro-Systems

    OpenAIRE

    Rainer Wansch

    2002-01-01

    This paper will describe the topology of wireless micro-systems networks and some of their key components. In particular we will deal with the antennas: loops, helices, F-antennas, patches and dielectrically loaded antennas.

  15. Ferrite attenuator modulation improves antenna performance

    Science.gov (United States)

    Hooks, J. C.; Larson, S. G.; Shorkley, F. H.; Williams, B. T.

    1970-01-01

    Ferrite attenuator inserted into appropriate waveguide reduces the gain of the antenna element which is causing interference. Modulating the ferrite attenuator to change the antenna gain at the receive frequency permits ground tracking until the antenna is no longer needed.

  16. 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

  17. Millimeter and submillimeter wave antenna structure

    Science.gov (United States)

    Rebiez, Gabriel M. (Inventor); Rutledge, David B. (Inventor)

    1989-01-01

    An integrated circuit antenna structure for transmitting or receiving millimeter and/or submillimeter wave radiation having an antenna relatively unimpaired by the antenna mounting arrangment is disclosed herein. The antenna structure of the present invention includes a horn disposed on a substrate for focusing electromagnetic energy with respect to an antenna. The antenna is suspended relative to the horn to receive or transmit the electromagnetic energy focused thereby.

  18. Microelectromechanical Systems Actuator Based Reconfigurable Printed Antenna

    Science.gov (United States)

    Simons, Rainee N. (Inventor)

    2005-01-01

    A polarization reconfigurable patch antenna is disclosed. The antenna includes a feed element, a patch antenna element electrically connected to the feed element, and at least one microelectromechanical systems (MEMS) actuator, with a partial connection to the patch antenna element along an edge of the patch antenna element. The polarization of the antenna can be switched between circular polarization and linear polarization through action of the at least one MEMS actuator.

  19. Patch antenna terahertz photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Palaferri, D.; Todorov, Y., E-mail: yanko.todorov@univ-paris-diderot.fr; Chen, Y. N.; Madeo, J.; Vasanelli, A.; Sirtori, C. [Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, Sorbonne Paris Cité, CNRS-UMS 7162, 75013 Paris (France); Li, L. H.; Davies, A. G.; Linfield, E. H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-04-20

    We report on the implementation of 5 THz quantum well photodetector exploiting a patch antenna cavity array. The benefit of our plasmonic architecture on the detector performance is assessed by comparing it with detectors made using the same quantum well absorbing region, but processed into a standard 45° polished facet mesa. Our results demonstrate a clear improvement in responsivity, polarization insensitivity, and background limited performance. Peak detectivities in excess of 5 × 10{sup 12} cmHz{sup 1/2}/W have been obtained, a value comparable with that of the best cryogenic cooled bolometers.

  20. Terahertz antenna electronic chopper

    Energy Technology Data Exchange (ETDEWEB)

    Sterczewski, L. A., E-mail: lukasz.sterczewski@pwr.edu.pl; Grzelczak, M. P.; Plinski, E. F. [Department of Electronics, Wroclaw University of Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw (Poland)

    2016-01-15

    In this paper, we present an electronic circuit used to bias a photoconductive antenna that generates terahertz radiation. The working principles and the design process for the device are discussed in detail. The noise and shape of the wave measurements for a built device are considered. Furthermore, their impact on a terahertz pulse and its spectra is also examined. The proposed implementation is simple to build, robust and offers a real improvement over THz instrumentation due to the frequency tuning. Additionally, it provides for galvanic isolation and ESD protection.

  1. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier

    2013-01-01

    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  2. Broadband antenna with frequency scanning

    Directory of Open Access Journals (Sweden)

    A. A. Shekaturin

    2014-06-01

    Full Text Available Relevance of this study. The main advantage of frequency scanning is simplicity of implementation. At this point, multifunctional usage of microwave modules is an urgent task, as well as their maximum simpler and cheaper. Antenna design and operation. The study is aimed at providing electric antenna with frequency scanning. It was based on the log-periodic antenna due to its wideband and negotiation capability over the entire operating frequency range. For this distribution line is bent in an arc of a circle in a plane blade while vibrators are arranged along the radius. Computer modeling of antennas with frequency scanning. Modeled with a non-mechanical motion antenna beam emitters representing system for receiving a radio frequency signal on mobile objects calculated for 1.8 GHz ... 4.2 GHz. The simulation was performed in a software environment for numerical modeling of electromagnetic «Feko 5.5». Analysis of the interaction of radiation is based on the method of moments. Findings. The result of this work is to propose a new design of the antenna with a frequency scanning method as agreed in a wide frequency range. In the studied technical solution provided by the rotation of NAM in the frequency range, and the matching of the antenna to the feed line is maintained. Application of this type of antennas on the proposed technical solution in communication systems will improve the communication reliability by maintaining coordination in the frequency range

  3. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  4. Absorption Efficiency of Receiving Antennas

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...

  5. Millimeter-wave antenna measurement

    NARCIS (Netherlands)

    Akkermans, J.A.G.; Dijk, R. van; Herben, M.H.A.J.

    2007-01-01

    A novel approach is presented to accurately measure the scattering parameters as well as the radiation pattern of planar antennas that operate in the millimeter-wave frequency band. To avoid interconnection problems, RF probes have been used to connect to the antenna. These RF probes are normally us

  6. Antennas for light and plasmons

    NARCIS (Netherlands)

    Dikken, Dirk Jan Willem

    2015-01-01

    Antennas have been used for over a century as emitters, scatterers and receivers of electromagnetic waves. All wireless communication devices, such as radio, mobile phones and satellite communication are strongly dependent on the capability of an antenna to localize propagating electromagnetic waves

  7. Tunable Antennas for Mobile Devices

    DEFF Research Database (Denmark)

    Morris, Art; Barrio, Samantha Caporal Del; Shin, J

    2014-01-01

    Modern mobile terminal design has been driven by the user interface and broadband connectivity. Real world RF performance has substantially fallen recently which impacts data rates, battery life and often causes lost connections. This has been caused by changing antenna location and reduced antenna...

  8. Mobile Phone Antenna Performance 2016

    DEFF Research Database (Denmark)

    Pedersen, Gert F.

    2016-01-01

    This study investigates the antenna performance of a number of mobile phones widely used in the Nordic Countries. The study is supported by the Nordic Council of Ministers. The antenna performance of the phones is vital for the phones ability to ensure radio coverage in low signal situations...

  9. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  10. Slot-Coupled Barbel Antenna

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant.......A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant....

  11. Optical antennas as nanoscale resonators.

    Science.gov (United States)

    Agio, Mario

    2012-02-07

    Recent progress in nanotechnology has enabled us to fabricate sub-wavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review the designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interactions, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.

  12. Minimum Q Electrically Small Antennas

    DEFF Research Database (Denmark)

    Kim, O. S.

    2012-01-01

    Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for the stored energies obtained through the vector spherical wave theory, it is shown that a magnetic-coated metal core reduces the internal stored energy of both TM1m and TE1m modes simultaneously, so that a self-resonant antenna with the Q approaching the fundamental minimum is created. Numerical results...... for a multiarm spherical helix antenna confirm the theoretical predictions. For example, a 4-arm spherical helix antenna with a magnetic-coated perfectly electrically conducting core (ka=0.254) exhibits the Q of 0.66 times the Chu lower bound, or 1.25 times the minimum Q....

  13. Optical antennas as nanoscale resonators

    CERN Document Server

    Agio, Mario

    2011-01-01

    Recent progress in nanotechnology has enabled us to fabricate subwavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interaction, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.

  14. Microstrip antenna on tunable substrate

    Science.gov (United States)

    Jose, K. A.; Varadan, Vijay K.; Varadan, Vasundara V.; Mohanan, P.

    1995-05-01

    The tunable patch antenna configurations are becoming popular and attractive in many aspects. This was mainly due to the advent of ferrite thin film technology and tunable substrate materials. The integration of monolithic microwave circuits and antennas are becoming easy today. In the development of magnetic tuning of microstrip patch on ferrite substrate is presented by Rainville and Harackewiez. Radiation characteristics of such antennas are presented by Pozer. Band width and radiation characteristics of such tunable antennas are measured and compared. Usually the substrate losses are considered in the analysis and metallization losses are assumed to be ideal. The analysis of magnetic tunable radiator including metallization and ferrite substrate losses are presented. However, all such tuning and integration of circuits and antennas are mainly on ferrite substrate due to magnetic tuning. Recently, Varadan et al. established that the BaxSr1-xTiO3 series ferroelectric materials such as Barium Strontium Titanate (BST) are well suited for microwave phase shifter applications. It could be possible to change the dielectric constant of these materials more than 50% depending on the BST composition, by changing the applied bias voltage. Also, the porosity of BST can be controlled during processing to produce dielectric constants in the range of 15 to 1500, with some trade off in tunability. In this paper, we are presenting the possibility of designing a microstrip patch antenna on such tunable substrate. Such antennas are having the major advantage of electronic tunability and compact size.

  15. 47 CFR 95.1213 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 95.1213 Section 95.1213... SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1213 Antennas. No antenna for a MedRadio transmitter shall be configured for permanent outdoor use. In addition, any MedRadio antenna used...

  16. Thermal Loss in High-Q Antennas

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Bahramzy, Pevand; Svendsen, Simon

    2014-01-01

    Tunable antennas are very promising for future generations of mobile communications, where antennas are required to cover a wide range operating bands. This letter aims at characterizing the loss mechanism of tunable antennas. Tunable antennas typically exhibit a high Quality factor (Q), which can...

  17. 47 CFR 95.1013 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 95.1013 Section 95.1013... SERVICES Low Power Radio Service (LPRS) General Provisions § 95.1013 Antennas. (a) The maximum allowable... this chapter, at the band edges. (b) AMTS stations must employ directional antennas. (c) Antennas...

  18. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Auxiliary antennas. 73.1675 Section 73.1675... Rules Applicable to All Broadcast Stations § 73.1675 Auxiliary antennas. (a)(1) An auxiliary antenna is one that is permanently installed and available for use when the main antenna is out of service...

  19. Double Structure Broadband Leaky Wave Antenna

    NARCIS (Netherlands)

    Neto, A.; Dijk, R. van; Filippo, M.

    2011-01-01

    A leaky wave antenna contains a first and a second leaky wave antenna structure back to back against each other. Each antenna structure comprises a dielectric body and an elongated wave carrying structure, such as a slot in a conductive ground plane. In each leaky wave antenna structure the body and

  20. Metamaterial antennas: the most successful metamaterial technology?

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2015-01-01

    The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas.......The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas....

  1. 47 CFR 73.753 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 73.753 Section 73.753... International Broadcast Stations § 73.753 Antenna systems. All international broadcasting stations shall operate with directional antennas. Such antennas shall be designed and operated so that the radiated power...

  2. 47 CFR 73.69 - Antenna monitors.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna monitors. 73.69 Section 73.69... Broadcast Stations § 73.69 Antenna monitors. (a) Each station using a directional antenna must have in operation at the transmitter site an FCC authorized antenna monitor. (b) In the event that the...

  3. 47 CFR 95.51 - Antenna height.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna height. 95.51 Section 95.51... SERVICES General Mobile Radio Service (GMRS) § 95.51 Antenna height. (a) Certain antenna structures used in... this chapter. (b) The antenna for a small base station or for a small control station must not be...

  4. 47 CFR 73.510 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 73.510 Section 73.510... Noncommercial Educational FM Broadcast Stations § 73.510 Antenna systems. (a) All noncommercial educational... § 73.316 concerning antenna systems contained in subpart B of this part. (b) Directional antenna....

  5. Metal Patch Antenna

    Science.gov (United States)

    Chamberlain, Neil F. (Inventor); Hodges, Richard E. (Inventor); Zawadzki, Mark S. (Inventor)

    2012-01-01

    Disclosed herein is a patch antenna comprises a planar conductive patch attached to a ground plane by a support member, and a probe connector in electrical communication with the conductive patch arranged to conduct electromagnetic energy to or from the conductive patch, wherein the conductive patch is disposed essentially parallel to the ground plane and is separated from the ground plane by a spacing distance; wherein the support member comprises a plurality of sides disposed about a central axis oriented perpendicular to the conductive patch and the ground plane; wherein the conductive patch is solely supported above the ground plane by the support member; and wherein the support member provides electrical communication between the planer conductive patch and the ground plane.

  6. Group Delay of High Q Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    become an issue, when working with high Q antennas, because of the steep phase shift over the frequency. In this paper, it is measured how large group delay variations can become, when going from a low Q antenna to a high Q antenna. The group delay of a low Q antenna is shown to be around 1.3 ns, whereas...... a high Q antenna has group delay of around 22 ns. It is due to this huge group delay variation characteristics of high Q antennas, that signal distortion might occur in the radio system with high Q antennas....

  7. DUAL BAND MONOPOLE ANTENNA DESIGN

    Directory of Open Access Journals (Sweden)

    P. Jithu

    2013-06-01

    Full Text Available The WLAN and Bluetooth applications become popular in mobile devices, integrating GSM and ISM bands operation in one compact antenna, can reduce the size of mobile devices. Recently, lot many investigations are carried out in designing a dual band antennas with operating frequencies in GSM band and in ISM band for mobile devices. Printed monopoles are under this investigation. In this paper, dual-band printed monopoles are presented to operate at GSM band i.e. 900 MHz and ISM band i.e. 2.4 GHz. We intend to observe the antenna characteristics on the network analyzer and verify the theoretical results with the practical ones.

  8. The collinear coaxial array antenna

    Science.gov (United States)

    Brammer, D. J.; Williams, D.

    1981-03-01

    A design of a coaxial vertical antenna proposed in the ARRL antenna handbook is analyzed. A numerical analysis was carried out using the moment method. A variety of antenna configurations in the 160 MHz design frequency are analyzed and current distribution, gain, polar diagrams and impedances are calculated. The analysis is carried out for simple configurations and extended to a case with 16 repeated center sections. The effects of using lossy cable in the construction is also investigated. A defect in the original ARRL design is rectified. An array of an overall length 5.33 wavelengths is shown to have a gain of 10.69 dB.

  9. Microstrip and printed antenna design

    CERN Document Server

    Bancroft, Randy

    2009-01-01

    The approach in this book is historical and practical. It covers abasic designsa in more detail than other microstrip antenna books that tend to skip important electrical properties and implementation aspects of these types of antennas. Examples include: quarter-wave patch, quarter by quarter patch, detailed design method for rectangular circularly polarized patch, the use of the TM11 (linear and broadside CP), TM21 (monopole CP pattern) and TM02 (monopole linear) circular patch modes in designs, dual-band antenna designs which allow for independent dual-band frequencies. Limits on broadband m

  10. Measurement of mobile antenna systems

    CERN Document Server

    Arai, Hiroyuki

    2012-01-01

    If you're involved with the design, installation or maintenance of mobile antenna systems, this thoroughly revised and updated edition of a classic Artech book offers you the most current and comprehensive coverage of all the mandatory measurement techniques you need for your work in the field. This Second Edition presents critical new material in key areas, including radiation efficiency measurement, mobile phone usage position, and MIMO (multiple-input/multiple-output) antennas.This unique resource provides in-depth examinations of all relevant mobile antenna measurement theories, along with

  11. Wideband Antennas for Modern Radar Systems

    OpenAIRE

    Ren, Yu-Jiun; Lai, Chieh-Ping

    2010-01-01

    In this chapter, the basics of the antenna and phased array are reviewed and different wideband antennas for modern radar systems are presented. The concepts of the radome and frequency selective surface are also reviewed. The main contents include important parameters of the antenna, and theory and design consideration of the array antenna. Various wideband antennas are introduced and their performances are demonstrated, including: (1) for the phased array radar, the slotted waveguide array ...

  12. Electrically floating, near vertical incidence, skywave antenna

    Science.gov (United States)

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  13. The new 34-meter antenna

    Science.gov (United States)

    Pompa, M. F.

    1986-01-01

    The new 34-m high efficiency Azimuth - Elevation antenna configuration, including its features, dynamic characteristics and performance at 8.4-GHz frequencies is described. The current-technology features of this antenna produce a highly reliable configuration by incorporation of a main wheel and track azimuth support, central pintle pivot bearing, close tolerance surface panels and all-welded construction. Also described are basic drive controls that, as slaved to three automatic microprocessors, provide accurate and safe control of the antenna's steering tasks. At this time antenna installations are completed at Goldstone and Canberra and have operationally supported the Voyager - Uranus encounter. A third installation is being constructed currently in Madrid and is scheduled for completion in late 1986.

  14. Inflatable Antennas Support Emergency Communication

    Science.gov (United States)

    2010-01-01

    Glenn Research Center awarded Small Business Innovation Research (SBIR) contracts to ManTech SRS Technologies, of Newport Beach, California, to develop thin film inflatable antennas for space communication. With additional funding, SRS modified the concepts for ground-based inflatable antennas. GATR (Ground Antenna Transmit and Receive) Technologies, of Huntsville, Alabama, licensed the technology and refined it to become the world s first inflatable antenna certified by the Federal Communications Commission. Capable of providing Internet access, voice over Internet protocol, e-mail, video teleconferencing, broadcast television, and other high-bandwidth communications, the systems have provided communication during the wildfires in California, after Hurricane Katrina in Mississippi, and following the 2010 Haiti earthquake.

  15. Dipoles, unintentional antennas and EMC

    Directory of Open Access Journals (Sweden)

    Berend Danker

    2008-01-01

    Full Text Available Radiated emissions from equipment commonly originate from electronic circuits that act as electric dipoles created by the signal voltage between the signal conductors or as magnetic dipoles formed by the signal current flowing in a loop. Direct emission is mostly small, but circuits often couple to long conductors or large wiring loops which act as antennas and are efficient radiators. A comparable situation exists when short dipole antennas or small wiring loops receive ambient noise (susceptibility. Usually the amplitude of noise sources or the susceptibility of circuits is an invariable. The dipole strength increases with the distance between the conductors and the area. Shielding and proper grounding decreases the interaction via unintentional antennas. Short-circuiting and the insertion of lossy ferrite cores reduce the efficiency of unintentional antennas.

  16. Electrically-driven optical antennas

    CERN Document Server

    Kern, Johannes; Prangsma, Jord C; Emmerling, Monika; Kamp, Martin; Hecht, Bert

    2015-01-01

    Unlike radiowave antennas, optical nanoantennas so far cannot be fed by electrical generators. Instead, they are driven by light or via optically active materials in their proximity. Here, we demonstrate direct electrical driving of an optical nanoantenna featuring an atomic-scale feed gap. Upon applying a voltage, quantum tunneling of electrons across the feed gap creates broadband quantum shot noise. Its optical frequency components are efficiently converted into photons by the antenna. We demonstrate that the properties of the emitted photons are fully controlled by the antenna architecture, and that the antenna improves the quantum efficiency by up to two orders of magnitude with respect to a non-resonant reference system. Our work represents a new paradigm for interfacing electrons and photons at the nanometer scale, e.g. for on-chip wireless data communication, electrically driven single- and multiphoton sources, as well as for background-free linear and nonlinear spectroscopy and sensing with nanometer...

  17. Diversity Gain through Antenna Blocking

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available As part of the typical usage mode, interaction between a handheld receiver antenna and the operator's RF absorbing body and nearby objects is known to generate variability in antenna radiation characteristics through blocking and pattern changes. It is counterintuitive that random variations in blocking can result in diversity gain of practical applicability. This diversity gain is quantified from a theoretical and experimental perspective. Measurements carried out at 1947.5 MHz verify the theoretical predictions, and a diversity gain of 3.1 dB was measured through antenna blocking and based on the utilized measurement setup. The diversity gain can be exploited to enhance signal detectability of handheld receivers based on a single antenna in indoor multipath environments.

  18. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  19. Living antennas on communication satellites

    DEFF Research Database (Denmark)

    Lumholt, Michael

    2003-01-01

    Crises change the global pattern of communication. The communications problems occur because the satellites are optimized to cover specific geographic areas, and these areas cannot be altered once the satellites are in Earth orbit. An effective solution to the problem is to equip communication sa...... satellites with "living" antennas that can adjust their radiation coverage areas according to the new demands. The development of living antennas is, therefore, among the focus areas identified and supported by the European Space Agency, ESA....

  20. Wideband Antenna for HPM Measurements

    Directory of Open Access Journals (Sweden)

    Kurkan Ivan

    2016-01-01

    Full Text Available The measurements of microwave pulses of gigawatt power level have a lot of constraints. A receiving antenna is a starting and core point of the measurement system. Waveguide based and dipole antennas have a limited wide bands, while the use of commercially available wideband antennas is restricted by their maximum peak power acceptances. The design of the wide band antenna with the small effective area was proposed. The characteristics of prototype were obtained in numerical simulations with ANSYS HFSS software and by calibration tests in the frequency band of 1–13 GHz. It has the effective area about the 1 mm2 in X-band and square-law dependence on the wavelength in a wide band. The cross polarization rate is more than 60 dB at the centre position and not less than 30 dB within the range of ±5° in azimuth and elevation angle. The wide beam radiation pattern forces a user to discriminate reflected signals. This antenna could greatly simplify the measurement system, replacing a set of narrow band antennas that connected to several recording channels.

  1. Some Recent Developments of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2012-01-01

    Full Text Available Although the microstrip antenna has been extensively studied in the past few decades as one of the standard planar antennas, it still has a huge potential for further developments. The paper suggests three areas for further research based on our previous works on microstrip antenna elements and arrays. One is exploring the variety of microstrip antenna topologies to meet the desired requirement such as ultrawide band (UWB, high gain, miniaturization, circular polarization, multipolarized, and so on. Another is to apply microstrip antenna to form composite antenna which is more potent than the individual antenna. The last is growing towards highly integration of antenna/array and feeding network or operating at relatively high frequencies, like sub-millimeter wave or terahertz (THz wave regime, by using the advanced machining techniques. To support our points of view, some examples of antennas developed in our group are presented and discussed.

  2. Magnetic antenna excitation of whistler modes. II. Antenna arrays

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2014-12-15

    The excitation of whistler modes from magnetic loop antennas has been investigated experimentally. The field topology of the excited wave driven by a single loop antenna has been measured for different loop orientations with respect to the uniform background field. The fields from two or more antennas at different locations are then created by superposition of the single-loop data. It is shown that an antenna array can produce nearly plane waves which cannot be achieved with single antennas. By applying a phase shift along the array, oblique wave propagation is obtained. This allows a meaningful comparison with plane wave theory. The Gendrin mode and oblique cyclotron resonance are demonstrated. Wave helicity and polarization in space and time are demonstrated and distinguished from the magnetic helicity of the wave field. The superposition of two oblique plane whistler modes produces in a “whistler waveguide” mode whose polarization and helicity properties are explained. The results show that single point measurements cannot properly establish the wave character of wave packets. The laboratory observations are relevant for excitation and detection of whistler modes in space plasmas.

  3. Modern lens antennas for communications engineering

    CERN Document Server

    Thornton, John

    2012-01-01

    The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

  4. Single Band Helical Antenna in Axial Mode

    Directory of Open Access Journals (Sweden)

    Parminder Singh

    2012-11-01

    Full Text Available Helical antennas have been widely used in a various useful applications, due to their low weight and low profile conformability, easy and cheap realization.Radiation properties of this antenna are examined both theoretically and experimentally. In this paper, an attempt has been made to investigate new helical antenna structure for Applications. CST MWS Software is used for the simulation and design calculations of the helical antennas. The axial ratio, return loss, VSWR, Directivity, gain, radiation pattern is evaluated. Using CST MWS simulation software proposed antenna is designed/simulated and optimized. The antenna exhibits a single band from 0 GHz to 3 GHz for GPS and several satellite applications

  5. Antennas in matter: Fundamentals, theory, and applications

    Science.gov (United States)

    King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

    1981-01-01

    The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

  6. Vehicle antenna development for mobile satellite applications

    Science.gov (United States)

    Woo, K.

    1988-01-01

    The paper summarizes results of a vehicle antenna program at JPL in support of a developing U.S. mobile satellite services (MSS) designed to provide telephone and data services for the continental United States. Two classes of circularly polarized vehicle antennas have been considered for the MSS: medium-gain, satellite-tracking antennas with 10-12-dBic gain; and low-gain, azimuthally omnidirectional antennas with 3-5-dBic gain. The design and performance of these antennas are described, and the two antennas are shown to have peculiar advantages and disadvantages.

  7. Microstrip antenna gain enhancement with metamaterial radome

    Science.gov (United States)

    Attachi, S.; Saleh, C.; Bouzouad, M.

    2017-01-01

    In this work, a high gain patch antenna using multilayer FSS radome is proposed for millimeter-wave applications. The antenna operating frequency is 43.5 GHz. The antenna/radome system consists of one, two, three, or four layers of metasurfaces placed in the near-field region of a microstrip patch antenna. The antenna/radome system gain is improved by 9 dBi compared to the patch antenna alone, and the radiation pattern half-power beamwidth is reduces to 20° in both E- and H-planes.

  8. Design of LTCC Based Fractal Antenna

    KAUST Repository

    AdbulGhaffar, Farhan

    2010-09-01

    The thesis presents a Sierpinski Carpet fractal antenna array designed at 24 GHz for automotive radar applications. Miniaturized, high performance and low cost antennas are required for this application. To meet these specifications a fractal array has been designed for the first time on Low Temperature Co-fired Ceramic (LTCC) based substrate. LTCC provides a suitable platform for the development of these antennas due to its properties of vertical stack up and embedded passives. The complete antenna concept involves integration of this fractal antenna array with a Fresnel lens antenna providing a total gain of 15dB which is appropriate for medium range radar applications. The thesis also presents a comparison between the designed fractal antenna and a conventional patch antenna outlining the advantages of fractal antenna over the later one. The fractal antenna has a bandwidth of 1.8 GHz which is 7.5% of the centre frequency (24GHz) as compared to 1.9% of the conventional patch antenna. Furthermore the fractal design exhibits a size reduction of 53% as compared to the patch antenna. In the end a sensitivity analysis is carried out for the fractal antenna design depicting the robustness of the proposed design against the typical LTCC fabrication tolerances.

  9. Multiband small zeroth-order metamaterial antenna

    Science.gov (United States)

    Dakhli, Nabil; Choubani, Fethi; David, Jacques

    2011-06-01

    A novel resonant metamaterial antenna based on the Composite Right/Left-Handed (CRLH) transmission line (TL) model is presented. The proposed small antenna is designed to operate simultaneously over multiple wireless services (UMTS-WLAN-WIMAX)

  10. Multifrequency Printed Antennas Loaded with Metamaterial Particles

    Directory of Open Access Journals (Sweden)

    D. Segovia-Vargas

    2009-06-01

    Full Text Available This paper provides a review of printed antennas loaded with metamaterial particles. This novel technique allows developing printed antennas with interesting features such as multifrequency (simultaneous operation over two or more frequency bands and multifunctionality (e. g. radiation pattern diversity. Moreover, compactness is also achieved and the main advantages of conventional printed antennas (light weight, low profile, low cost ... are maintained. Different types of metamaterial-loaded printed antennas are reviewed: printed dipoles and patch antennas. Several prototypes are designed, manufactured and measured showing good results. Furthermore, simple but accurate equivalent models are proposed. These models allow an easy and quick design of metamaterial-loaded printed antennas. Finally, two interesting applications based on the proposed antennas are reviewed: the patch antennas are used as radiating elements of emerging active RFID systems in the microwave band and the metamaterial-loaded printed dipoles are employed to increase the performance of log-periodic arrays.

  11. VLBI Antenna Calibration via GPS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to investigate and develop an inexpensive system to determine: 1)VLBI antenna properties such as axis-offset, non-intersection of axis and antenna...

  12. High-temperature superconductor antenna investigations

    Science.gov (United States)

    Karasack, Vincent G.

    1990-10-01

    The use of superconductors to increase antenna radiation efficiency and gain is examined. Although the gain of all normal-metal antennas can be increased through the use of superconductors, some structures have greater potential for practical improvement than others. Some structures suffer a great degradation in bandwidth when replaced with superconductors, while for others the improvement in efficiency is trivial due to the minimal contribution of the conductor loss mechanism to the total losses, or the already high efficiency of the structure. The following antennas and related structures are discussed: electrically small antennas, impedance matching of antennas, microstrip antennas, microwave and millimeter-wave antenna arrays, and superdirective arrays. The greatest potential practical improvements occur for large microwave and millimeter-wave arrays and the impedance matching of antennas.

  13. Mode-matching for Optical Antennas

    CERN Document Server

    Feichtner, Thorsten; Hecht, Bert

    2016-01-01

    The emission rate of a point dipole can be strongly increased in presence of a well-designed optical antenna. Yet, optical antenna design is largely based on radio-frequency rules, ignoring e.g.~ohmic losses and non-negligible field penetration in metals at optical frequencies. Here we combine reciprocity and Poynting's theorem to derive a set of optical-frequency antenna design rules for benchmarking and optimizing the performance of optical antennas driven by single quantum emitters. Based on these findings a novel plasmonic cavity antenna design is presented exhibiting a considerably improved performance compared to a reference two-wire antenna. Our work will be useful for the design of high-performance optical antennas and nanoresonators for diverse applications ranging from quantum optics to antenna-enhanced single-emitter spectroscopy and sensing.

  14. Design considerations for low antenna correlation and mutual coupling reduction in multi antenna terminals

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2007-01-01

    The influence of mutual coupling on the envelope correlation between two identical planar inverted F-antennas (PIFA) are investigated. The capacity of a multiple-input multiple-output (MIMO) antenna system strongly depends on the correlation between the antennas. By placing two antennas in a fixe...

  15. Application of the SWE-to-PWE antenna diagnostics technique to an offset reflector antenna

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Frandsen, Aksel; Breinbjerg, Olav

    2008-01-01

    Electrical and mechanical errors in an antenna may seriously affect the antenna's performance. Although their presence is usually detected by anomalies in the antenna's far-field pattern, their identification is normally possible only through an analysis of the antenna's extreme near field. The r...

  16. Non-Reciprocal Optical Antennas

    CERN Document Server

    Castro-Lopez, Marta; van Hulst, Niek F

    2014-01-01

    Plasmonics aims to interface photonics and electronics. Finding optical, near-field analogues of much used electro-technical components is crucial to the success of such a platform. Here we present the plasmonic analogue of a non-reciprocal antenna. For non-reciprocality in a plasmonic context, the optical excitation and emission resonances of the antenna need to be an orthogonal set. We show that nonlinear excitation of metal nanoantennas creates a sufficient shift between excitation and emission wavelengths that they can be interpreted as decoupled, allowing for independent tuning of excitation and emission properties along different spatial dimensions. This leads, for given excitation wavelength and polarization, to independent optimization of emission intensity, frequency spectrum, polarization and angular spectrum. Non-reciprocal optical antennas of both gold and aluminum are characterized and shown to be useful as e.g. nonlinear signal transducers or nanoscale sources of widely tunable light.

  17. Compact Low Frequency Radio Antenna

    Science.gov (United States)

    Punnoose, Ratish J.

    2008-11-11

    An antenna is disclosed that comprises a pair of conductive, orthogonal arches and a pair of conductive annular sector plates, wherein adjacent legs of each arch are fastened to one of the annular sector plates and the opposite adjacent pair of legs is fastened to the remaining annular sector plate. The entire antenna structure is spaced apart from a conductive ground plane by a thin dielectric medium. The antenna is driven by a feed conduit passing through the conductive ground plane and dielectric medium and attached to one of the annular sector plates, wherein the two orthogonal arched act as a pair of crossed dipole elements. This arrangement of elements provides a radiation pattern that is largely omni-directional above the horizon.

  18. Dual-Antenna Microwave Reception Without Switching

    Science.gov (United States)

    Hartop, Robert W.

    1994-01-01

    Receiver remains connected to both antennas, transmitter switched to connect it to one or other. Combination of hybrid junction, circulators, and filter provides simultaneous reception paths from both antennas without significantly altering radiation patterns of antennas. Communication system considered for use in spacecraft and in which mechanical switch permitted on downlink but not on uplink. Applicable to terrestrial microwave communication stations subject to dual-antenna requirements.

  19. Rectangular dielectric resonator antennas theory and design

    CERN Document Server

    Yaduvanshi, Rajveer S

    2016-01-01

    This book covers resonating modes inside device and gives insights into antenna design, impedance and radiation patterns. It discusses how higher-order modes generation and control impact bandwidth and antenna gain. The text covers new approaches in antenna design by investigation hybrid modes, H_Z and E_Z fields available simultaneously, and analysis and modelling on modes with practical applications in antenna design. The book will be prove useful to students, researchers and professionals alike.

  20. Wideband irregular-shaped fractal antennas

    OpenAIRE

    Kolesov, V. V.; Krupenin, S. V.

    2007-01-01

    This paper proposes an algorithm of generating fully reproducible irregular fractal structures for antenna design. Three types of pseudorandom fractal clusters are introduced. The multi-frequency behavior of the irregular-shaped fractal antennas is studied by means of numerical analysis. The antenna behavior is studied under feeder displacement. As shown by numerical results feeder displacements allow one to control the spatial-frequency antenna characteristics.

  1. Mode-matching for Optical Antennas

    OpenAIRE

    Feichtner, Thorsten; Christiansen, Silke; Hecht, Bert

    2016-01-01

    The emission rate of a point dipole can be strongly increased in presence of a well-designed optical antenna. Yet, optical antenna design is largely based on radio-frequency rules, ignoring e.g.~ohmic losses and non-negligible field penetration in metals at optical frequencies. Here we combine reciprocity and Poynting's theorem to derive a set of optical-frequency antenna design rules for benchmarking and optimizing the performance of optical antennas driven by single quantum emitters. Based ...

  2. Optical antenna effect in semiconducting nanowires.

    Science.gov (United States)

    Chen, G; Wu, Jian; Lu, Qiujie; Gutierrez, H R; Xiong, Qihua; Pellen, M E; Petko, J S; Werner, D H; Eklund, P C

    2008-05-01

    We report on investigations of the interaction of light with nanoscale antennae made from crystalline GaP nanowires (NWs). Using Raman scattering, we have observed strong optical antenna effects which we identify with internal standing wave photon modes of the wire. The antenna effects were probed in individual NWs whose diameters are in the range 40 optical antenna effect" in semiconducting NWs is essential to the analysis of all electro-optic effects in small diameter filaments.

  3. Optical antenna for photofunctional molecular systems.

    Science.gov (United States)

    Ikeda, Katsuyoshi; Uosaki, Kohei

    2012-02-06

    Optical antennas can enhance the efficiency of photon-molecule interactions. To design efficient antenna structures, it is essential to consider physicochemical aspects in addition to electromagnetic considerations. Specifically, chemical interactions between optical antennas and molecules have to be controlled to enhance the overall efficiency. For this purpose, sphere-plane nanostructures are suitable optical antennas for molecular-modified functional electrode systems when a well-defined electrode is utilized as a platform.

  4. Electromechanically Tunable Suspended Optical Nano-antenna

    OpenAIRE

    Chen, Kai; Razinskas, Gary; Feichtner, Thorsten; Grossmann, Swen; Christiansen, Silke; Hecht, Bert

    2016-01-01

    Coupling mechanical degrees of freedom with plasmonic resonances has potential applications in optomechanics, sensing, and active plasmonics. Here we demonstrate a suspended two-wire plasmonic nano-antenna acting like a nano-electrometer. The antenna wires are supported and electrically connected via thin leads without disturbing the antenna resonance. As a voltage is applied, equal charges are induced on both antenna wires. The resulting equilibrium between the repulsive Coulomb force and th...

  5. Estimation of complex permittivity using loop antenna

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2004-01-01

    A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna.......A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna....

  6. Advanced antennas for SAR spacecraft

    Science.gov (United States)

    Gail, William B.

    1993-01-01

    Single and multi-frequency antenna concepts were developed to evaluate the feasibility of building large aperture polarimetric synthetic aperture radar (SAR) systems to be launched in low cost vehicles such as the Delta 2. The antennas are 18.9 m long by 2.6 m wide (L-band) and achieve single polarization imaging to an incidence angle of 55 degrees and dual/quad imaging to 42 degrees. When combined with strawman spacecraft designs, both concepts meet the mass and volume constraints imposed by a Delta 2 launch.

  7. Accurate determination of antenna directivity

    DEFF Research Database (Denmark)

    Dich, Mikael

    1997-01-01

    The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...

  8. Antenna reconfiguration verification and validation

    Science.gov (United States)

    Becker, Robert C. (Inventor); Meyers, David W. (Inventor); Muldoon, Kelly P. (Inventor); Carlson, Douglas R. (Inventor); Drexler, Jerome P. (Inventor)

    2009-01-01

    A method of testing the electrical functionality of an optically controlled switch in a reconfigurable antenna is provided. The method includes configuring one or more conductive paths between one or more feed points and one or more test point with switches in the reconfigurable antenna. Applying one or more test signals to the one or more feed points. Monitoring the one or more test points in response to the one or more test signals and determining the functionality of the switch based upon the monitoring of the one or more test points.

  9. Nested-cone transformer antenna

    Science.gov (United States)

    Ekdahl, Carl A.

    1991-01-01

    A plurality of conical transmission lines are concentrically nested to form n output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated.

  10. Small X-Band Oscillator Antennas

    Science.gov (United States)

    Lee, Richard Q.; Miranda, Felix A.; Clark, Eric B.; Wilt, David M.; Mueller, Carl H.; Kory, Carol L.; Lambert, Kevin M.

    2009-01-01

    A small, segmented microstrip patch antenna integrated with an X-band feedback oscillator on a high-permittivity substrate has been built and tested. This oscillator antenna is a prototype for demonstrating the feasibility of such devices as compact, low-power-consumption building blocks of advanced, lightweight, phased antenna arrays that would generate steerable beams for communication and remotesensing applications.

  11. 47 CFR 101.517 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 101.517 Section 101.517... SERVICES 24 GHz Service and Digital Electronic Message Service § 101.517 Antennas. (a) Transmitting antennas may be omnidirectional or directional, consistent with coverage and interference requirements....

  12. 47 CFR 101.115 - Directional antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Directional antennas. 101.115 Section 101.115... SERVICES Technical Standards § 101.115 Directional antennas. (a) Unless otherwise authorized upon specific... antenna adjusted with the center of the major lobe of radiation in the horizontal plane directed...

  13. New Concepts in Electromagnetic Materials and Antennas

    Science.gov (United States)

    2015-01-01

    AFRL-RY-WP-TR-2014-0233 NEW CONCEPTS IN ELECTROMAGNETIC MATERIALS AND ANTENNAS Jeffrey Allen, Naftali Herscovici, Brad Kramer, and...Bae-Ian Wu Antennas & Electromagnetics Technology Branch Multispectral Sensing & Detection Division JANUARY 2015 Final Report...Signature// //Signature// BRADLEY A. KRAMER, Program Manager TONY C. KIM, Branch Chief Antenna & Electromagnetic Technology

  14. 47 CFR 95.859 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 95.859 Section 95.859... SERVICES 218-219 MHz Service Technical Standards § 95.859 Antennas. (a) The overall height from ground to topmost tip of the CTS antenna shall not exceed the height necessary to assure adequate service....

  15. 47 CFR 73.816 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antennas. 73.816 Section 73.816... Low Power FM Broadcast Stations (LPFM) § 73.816 Antennas. (a) Permittees and licensees may employ nondirectional antennas with horizontal only polarization, vertical only polarization, circular polarization...

  16. Coplanar waveguide feed for microstrip patch antennas

    Science.gov (United States)

    Smith, R. L.; Williams, J. T.

    1992-01-01

    A coplanar waveguide (CPW) loop is shown to be an effective low VSWR feed for microstrip antennas. The low VSWR transition between the CPW and the antenna is obtained without the use of a matching circuit, and it is relatively insensitive to the position of the antenna and the feed.

  17. Numerical Study of Planar GPR Antenna Measurements

    DEFF Research Database (Denmark)

    Meincke, Peter; Hansen, Thorkild

    2004-01-01

    The formulation of planar near-field measurements of GPR antennas determines the plane-wave spectra of the GPR antenna in terms of measurements obtained with a buried probe as the GPR antenna moves over a scan plane on the ground. A numerical study investigates how the formulation is affected by (1...

  18. Collapsible structure for an antenna reflector

    Science.gov (United States)

    Trubert, M. R. (Inventor)

    1973-01-01

    A collapsible support for an antenna reflector for use in supporting spacecraft antennas is described. The support has a regid base and a number of struts which are pivoted at the base. The deployment of the struts and their final configuration for supporting the antenna are illustrated.

  19. Isolation between three antennas at 700 MHz

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Svendsen, Simon; Pedersen, Gert F.

    2015-01-01

    To address the antenna design challenges posed by many frequency bands, introduced with long-term evolution deployment, this study proposes the use of separate transmit (Tx) and receive (Rx) narrow-band antennas. In addition, a diversity Rx (Dx) antenna is needed for multiple-input multiple...

  20. 47 CFR 74.641 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 74.641 Section 74.641... Stations § 74.641 Antenna systems. (a) For fixed stations operating above 2025 MHz, the following standards apply: (1) Fixed TV broadcast auxiliary stations shall use directional antennas that meet...

  1. 47 CFR 80.923 - Antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna system. 80.923 Section 80.923... MARITIME SERVICES Compulsory Radiotelephone Installations for Small Passenger Boats § 80.923 Antenna system. An antenna must be provided in accordance with the applicable requirements of § 80.81 of this...

  2. Future Vogues in Handset Antenna Systems

    DEFF Research Database (Denmark)

    Pelosi, Mauro; Pedersen, Gert Frølund

    2011-01-01

    This paper exemplifies future trends in handset antenna systems, contextualizing their historical evolution and anticipating novel paradigms. It is shown through numerical simulations how narrow-band antennas used in transceiver separation mode can reduce the total loss in presence of the user......’s hand, improving at the same time the antenna isolation....

  3. Antenna Construction and Propagation of Radio Waves.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on antenna construction and propagation of radio waves is designed to provide communicators with instructions in the selection and/or construction of the proper antenna(s) for use with current field radio equipment. Introductory materials include…

  4. Orthogonal antenna architecture for MIMO handsets

    DEFF Research Database (Denmark)

    Tatomirescu, Alexandru; Alrabadi, Osama; Pedersen, Gert Frølund

    2012-01-01

    The paper presents a method for decorrelating the antenna elements of a MIMO system in a compact handheld terminal at low bands. The architecture of the antenna system induces orthogonal currents over the closely spaced antennas resulting in a correlation free system. Nevertheless, due to the small...

  5. 47 CFR 80.1017 - Antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna system. 80.1017 Section 80.1017... MARITIME SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1017 Antenna system. (a) An antenna must be provided for nonportable bridge-to-bridge radiotelephone...

  6. 47 CFR 74.737 - Antenna location.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna location. 74.737 Section 74.737... Booster Stations § 74.737 Antenna location. (a) An applicant for a new low power TV, TV translator, or TV.... (b) The transmitting antenna should be placed above growing vegetation and trees lying in...

  7. 47 CFR 78.105 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 78.105 Section 78.105... SERVICE Technical Regulations § 78.105 Antenna systems. (a) For fixed stations operating in the 12.7-13.2... directional antennas that meet the performance standards indicated in the following table. (i) Stations...

  8. 47 CFR 80.967 - Antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna system. 80.967 Section 80.967... MARITIME SERVICES Radiotelephone Installation Required for Vessels on the Great Lakes § 80.967 Antenna system. The antenna must be omni-directional, vertically polarized and located as high as practicable...

  9. Improved Gain Microstrip Patch Antenna

    Science.gov (United States)

    2015-08-06

    same as one half wavelength, λ, of a design frequency for reception or transmission by the antenna 10. Patch 16 can be joined to a coaxial feed 18. A...expressed in the appended claims. [0024] The foregoing description of the preferred embodiments of the invention has been presented for purposes of

  10. DSS 13 microprocessor antenna controller

    Science.gov (United States)

    Gosline, R. M.

    1988-01-01

    A microprocessor-based antenna monitor and control system with multiple CPUs are described. The system was developed as part of the unattended station project for DSS 13 and was enhanced for use by the SETI project. The operational features, hardware, and software designs are described, and a discussion is provided of the major problems encountered.

  11. Installing the antenna for STELLA

    CERN Multimedia

    1979-01-01

    The 3 metre diameter antenna for the STELLA satellite communication project is lowered into position on the roof of the Computer Building (see Weekly Bulletin 48/79 and CERN Courier 19 (1979) 444). STELLA stands for Satellite Transmission Experiment Linking Laboratories.

  12. The Antenna Bride and Bridegroom

    Science.gov (United States)

    2007-03-01

    ALMA Achieves Major Milestone With Antenna-Link Success The Atacama Large Millimeter/submillimeter Array (ALMA), an international telescope project, reached a major milestone on 2 March, when two 12-m ALMA prototype antennas were first linked together as an integrated system to observe an astronomical object. "This achievement results from the integration of many state-of-the-art components from Europe and North America and bodes well for the success of ALMA in Chile", said Catherine Cesarsky, ESO's Director General. ESO PR Photo 10/07 ESO PR Photo 10/07 The Prototype Antennas The milestone achievement, technically termed 'First Fringes', came at the ALMA Test Facility (ATF), located near Socorro in New Mexico. Faint radio waves emitted by the planet Saturn were collected by two ALMA prototype antennas, then processed by new, high-tech electronics to turn the two antennas into a single, high-resolution telescope system, called an interferometer. The planet's radio emissions at a frequency of 104 gigahertz were tracked by the ALMA system for more than an hour. Such pairs of antennas are the basic building blocks of the multi-antenna imaging system ALMA. In such a system, the signals recorded by each antenna are electronically combined with the signals of every other antenna to form a multitude of pairs. Each pair contributes unique information that is used to build a highly detailed image of the astronomical object under observation. When completed in the year 2012, ALMA will have 66 antennas. "Our congratulations go to the dedicated team of scientists, engineers and technicians who produced this groundbreaking achievement for ALMA. Much hard work and many long hours went into this effort, and we appreciate it all. This team should be very proud today," said NRAO Director Fred K.Y. Lo. "With this milestone behind us, we now can proceed with increased confidence toward completing ALMA," he added. ALMA, located at an elevation of 5,000m in the Atacama Desert of

  13. Coupling between minimum scattering antennas

    DEFF Research Database (Denmark)

    Andersen, J.; Lessow, H; Schjær-Jacobsen, Hans

    1974-01-01

    Coupling between minimum scattering antennas (MSA's) is investigated by the coupling theory developed by Wasylkiwskyj and Kahn. Only rotationally symmetric power patterns are considered, and graphs of relative mutual impedance are presented as a function of distance and pattern parameters. Crossed...

  14. Photogrammetry Of A Parabolic Antenna

    Science.gov (United States)

    Merrick, W. D.; Lansing, F. L.; Stoller, F. W.; Lobb, V. B.

    1988-01-01

    Surface measured with accuracy better than 10 to the negative fifth power times diameter. Report describes use of advanced close-range photogrammetry to determine deviations of 34-m-diameter antenna main reflector and subreflector from nominal paraboloidal shapes. Measurements enable removal of linear offsets and angular misalignments of subreflector, with consequent increase of 4 percent in aperture efficiency.

  15. Forward Scattering of Loaded and Unloaded Antennas

    DEFF Research Database (Denmark)

    Gustafsson, Mats; Andersen, Jørgen Bach; Kristensson, Gerhard

    2012-01-01

    Forward scattering of antennas is related to antenna performance via the forward-scattering sum rule. The forward-scattering sum rule is an integral identity that shows that a weighted integral of the extinction cross section over all spectrum is proportional to the static polarizability...... of the antenna structure. Here, the forward-scattering sum rule is experimentally verified for loaded, short-circuit, and open-circuit cylindrical dipole antennas. It is also shown that the absorption efficiency cannot be greater than 1/2 for reciprocal linearly polarized lossless matched antennas...

  16. Nanorod optical antennas for dipolar transitions

    CERN Document Server

    Taminiau, Tim H; van Hulst, Niek F

    2009-01-01

    Optical antennas link objects to light. Here, we analyze metal nanorod antennas as cavities with variable reflection coefficients to derive the interaction of dipolar transitions with radiation through the antenna modes. The presented analytical model accurately describes the complete emission process, and is summarized in a phase-matching equation. We show how antenna modes evolve as they become increasingly more bound, i.e. plasmonic. The results illustrate why efficient antennas should not be too plasmonic, and how subradiant even modes can evolve into weakly-interacting dark modes. Our description is valid for the interaction of nanorods with light in general, and is thus widely applicable.

  17. Multi-antenna synthetic aperture radar

    CERN Document Server

    Wang, Wen-Qin

    2013-01-01

    Synthetic aperture radar (SAR) is a well-known remote sensing technique, but conventional single-antenna SAR is inherently limited by the minimum antenna area constraint. Although there are still technical issues to overcome, multi-antenna SAR offers many benefits, from improved system gain to increased degrees-of-freedom and system flexibility. Multi-Antenna Synthetic Aperture Radar explores the potential and challenges of using multi-antenna SAR in microwave remote sensing applications. These applications include high-resolution imaging, wide-swath remote sensing, ground moving target indica

  18. Foldable nanopaper antennas for origami electronics.

    Science.gov (United States)

    Nogi, Masaya; Komoda, Natsuki; Otsuka, Kanji; Suganuma, Katsuaki

    2013-05-21

    Foldable antennas are required for small-sized electronic devices with high portability. Antennas on plastic substrates provide high flexibility and high sensitivity but are not foldable. Antennas on paper substrates are foldable, but their sensitivity is poor because of their coarse surfaces. In this paper, nanopapers with smooth surfaces and high foldability are fabricated from 30 nm wide cellulose nanofibers for use as foldable antenna substrates. Silver nanowires are then printed on the nanopapers to act as antenna lines. These nanopaper antennas with silver nanowires exhibit high sensitivity because of their smooth surfaces and high foldability because of their network structures. Also, their high foldability allows the mechanical tuning of their resonance points over a wide frequency range without using additional components such as condensers and coils. Nanopaper antennas with silver nanowires are therefore suitable for the realization of future foldable electronics.

  19. Improvement of antenna decoupling in radar systems

    Science.gov (United States)

    Anchidin, Liliana; Topor, Raluca; Tamas, Razvan D.; Dumitrascu, Ana; Danisor, Alin; Berescu, Serban

    2015-02-01

    In this paper we present a type of antipodal Vivaldi antenna design, which can be used for pulse radiation in UWB communication. The Vivaldi antenna is a special tapered slot antenna with planar structure which is easily to be integrated with transmitting elements and receiving elements to form a compact structure. When the permittivity is very large, the wavelength of slot mode is so short that the electromagnetic fields concentrate in the slot to form an effective and balanced transmission line. Due to its simple structure and small size the Vivaldi antennas are one of the most popular designs used in UWB applications. However, for a two-antenna radar system, there is a high mutual coupling between two such antennas due to open configuration. In this paper, we propose a new method for reducing this effect. The method was validated by simulating a system of two Vivaldi antennas in front of a standard target.

  20. Metamaterial-Inspired Efficient Electrically Small Antenna

    DEFF Research Database (Denmark)

    Erentok, Aycan; Ziolkowski, R. W.

    2008-01-01

    Planar two-dimensional (2D) and volumetric three-dimensional (3D) metamaterial-inspired efficient electrically-small antennas that are easy to design; are easy and inexpensive to build; and are easy to test; are reported, i.e., the EZ antenna systems. The proposed 2D and 3D electrical- and magnetic......-based EZ antennas are shown to be naturally matched to a 50 source, i.e., without the introduction of a matching network. It is demonstrated numerically that these EZ antennas have high radiation efficiencies with very good impedance matching between the source and the antenna and, hence, that they have...... high overall efficiencies. The reported 2D and 3D EZ antenna designs are linearly scalable to a wide range of frequencies and yet maintain their easy-to-build characteristics. Several versions of the 2D EZ antennas were fabricated and tested. The measurement results confirm the performance predictions...

  1. Antenna gain measurements in the intermediate-field zone

    Science.gov (United States)

    Anchidin, Liliana; Bari, Farida; Dumitrascu, Ana; Paun, Mirel; Deacu, Daniela; Tasu, Sorin; Danisor, Alin; Tamas, Razvan D.

    2016-12-01

    Antenna gain is usually evaluated under far-field conditions. Furthermore, Friis transmission formula can solely be applied when antenna size can be neglected with respect to the distance between the measuring antenna and the antenna under test. In this paper, we show that by applying the distance averaging technique the far-field and antenna size constraints can be overcome. Our method was validated by measuring a monopole antenna and a Vivaldi antenna in an open area test site (OATS).

  2. Negative ion source with external RF antenna

    Science.gov (United States)

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  3. Transparent antennas for solar cell integration

    Science.gov (United States)

    Yasin, Tursunjan

    Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells' point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements.

  4. Plasmonic Antenna Coupling for QWIPs

    Science.gov (United States)

    Hong, John

    2007-01-01

    In a proposed scheme for coupling light into a quantum-well infrared photodetector (QWIP), an antenna or an array of antennas made of a suitable metal would be fabricated on the face of what would otherwise be a standard QWIP. This or any such coupling scheme is required to effect polarization conversion: Light incident perpendicularly to the face is necessarily polarized in the plane of the face, whereas, as a matter of fundamental electrodynamics and related quantum selection rules, light must have a non-zero component of perpendicular polarization in order to be absorbed in the photodetection process. In a prior coupling scheme, gratings in the form of surface corrugations diffract normally gles, thereby imparting some perpendicular polarization. Unfortunately, the corrugation- fabrication process increases the overall nonuniformity of a large QWIP array. The proposed scheme is an alternative to the use of surface corrugations.

  5. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

    This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

  6. Photo-generated THz antennas

    Science.gov (United States)

    Georgiou, G.; Tyagi, H. K.; Mulder, P.; Bauhuis, G. J.; Schermer, J. J.; Rivas, J. Gómez

    2014-01-01

    Electromagnetic resonances in conducting structures give rise to the enhancement of local fields and extinction efficiencies. Conducting structures are conventionally fabricated with a fixed geometry that determines their resonant response. Here, we challenge this conventional approach by demonstrating the photo-generation of THz linear antennas on a flat semiconductor layer by the structured optical illumination through a spatial light modulator. Free charge carriers are photo-excited only on selected areas, which enables the realization of different conducting antennas on the same sample by simply changing the illumination pattern, thus without the need of physically structuring the sample. These results open a wide range of possibilities for the all-optical spatial control of resonances on surfaces and the concomitant control of THz extinction and local fields.

  7. The planar parabolic optical antenna.

    Science.gov (United States)

    Schoen, David T; Coenen, Toon; García de Abajo, F Javier; Brongersma, Mark L; Polman, Albert

    2013-01-09

    One of the simplest and most common structures used for directing light in macroscale applications is the parabolic reflector. Parabolic reflectors are ubiquitous in many technologies, from satellite dishes to hand-held flashlights. Today, there is a growing interest in the use of ultracompact metallic structures for manipulating light on the wavelength scale. Significant progress has been made in scaling radiowave antennas to the nanoscale for operation in the visible range, but similar scaling of parabolic reflectors employing ray-optics concepts has not yet been accomplished because of the difficulty in fabricating nanoscale three-dimensional surfaces. Here, we demonstrate that plasmon physics can be employed to realize a resonant elliptical cavity functioning as an essentially planar nanometallic structure that serves as a broadband unidirectional parabolic antenna at optical frequencies.

  8. Omnidirectional antenna having constant phase

    Energy Technology Data Exchange (ETDEWEB)

    Sena, Matthew

    2017-04-04

    Various technologies presented herein relate to constructing and/or operating an antenna having an omnidirectional electrical field of constant phase. The antenna comprises an upper plate made up of multiple conductive rings, a lower ground-plane plate, a plurality of grounding posts, a conical feed, and a radio frequency (RF) feed connector. The upper plate has a multi-ring configuration comprising a large outer ring and several smaller rings of equal size located within the outer ring. The large outer ring and the four smaller rings have the same cross-section. The grounding posts ground the upper plate to the lower plate while maintaining a required spacing/parallelism therebetween.

  9. EHF multifunction phased array antenna

    Science.gov (United States)

    Solbach, Klaus

    1986-07-01

    The design of a low cost demonstration EHF multifunction-phased array antenna is described. Both, the radiating elements and the phase-shifter circuits are realized on microstrip substrate material in order to allow photolithographic batch fabrication. Self-encapsulated beam-lead PIN-diodes are employed as the electronic switch elements to avoid expensive hermetic encapsulation of the semiconductors or complete circuits. A space-feed using a horn-radiator to illuminate the array from the front-side is found to be the simplest and most inexpensive feed. The phased array antenna thus operates as a reflect-array, the antenna elements employed in a dual role for the collection of energy from the feed-horn and for the re-radiation of the phase-shifted waves (in transmit-mode). The antenna is divided into modules containing the radiator/phase-shifter plate plus drive- and BITE-circuitry at the back. Both drive- and BITE-components use gate-array integrated circuits especially designed for the purpose. Several bus-systems are used to supply bias and logical data flows to the modules. The beam-steering unit utilizes several signal processors and high-speed discrete adder circuits to combine the pointing, frequency and beam-shape information from the radar system computer with the stored phase-shift codes for the array elements. Since space, weight and power consumption are prime considerations only the most advanced technology is used in the design of both the microwave and the digital/drive circuitry.

  10. Quasi-optical active antennas

    Science.gov (United States)

    Moussessian, Alina

    Quasi-optical power combiners such as quasi-optical grids provide an efficient means of combining the output power of many solid-state devices in free space. Unlike traditional power combiners no transmission lines are used, therefore, high output powers with less loss can be achieved at higher frequencies. This thesis investigates four different active antenna grids. The first investigation is into X-band High Electron Mobility Transistor (HEMT) grid amplifiers. Modelling and stability issues of these grids are discussed, and gain and power measurements are presented. A grid amplifier with a maximum efficiency of 22.5% at 10 GHz and a peak gain of 11dB is presented. The second grid is a varactor grid used as a positive feedback network for a grid amplifier to construct a tunable grid oscillator. Reflection measurements for the varactor grid show a tuning range of 1.2 GHz. The third grid is a self- complementary grid amplifier. The goal is to design a new amplifier with a unit cell structure that can be directly modelled using CAD tools. The properties of self- complementary structures are studied and used in the design of this new amplifier grid. The fourth grid is a 12 x 12 terahertz Schottky grid frequency doubler with a measured output power of 24 mW at 1 THz for 3.1-μs 500-GHz input pulses with a peak power of 47 W. A passive millimeter-wave travelling-wave antenna built on a dielectric substrate is also presented. Calculations indicate that the antenna has a gain of 15 dB with 3-dB beamwidths of 10o in the H-plane and 64o in the E-plane. Pattern measurements at 90 GHz support the theory. The antenna is expected to have an impedance in the range of 50/Omega to 80/Omega.

  11. Hybrid Maritime Satellite Communication Antenna

    DEFF Research Database (Denmark)

    Smith, Thomas Gunst

    Hybrid antennas for a maritime satellite communication terminal with simultaneous operation at L- and Ka-band have been investigated. The frequency bands of interest are 1; 525:0 1; 660:5 MHz (RX+TX, RHCP), 19:7 20:2 (RX, LHCP) and 29:5 30:0 GHz (TX, RHCP), which are all part of the Inmarsat BGAN...

  12. Twin-Axial Wire Antenna

    Science.gov (United States)

    2015-08-06

    COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...by mutual capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of...capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of the antenna in

  13. A multi octaves directive dielectric lens: The Pyramid Antenna

    NARCIS (Netherlands)

    Marliani, L.; Bruni, S.; Neto, A.

    2005-01-01

    Leaky wave antennas have been investigated for a long time and are typically an inexpensive solution for beam scanning antennas. We have designed a novel antenna topology, named the pyramid antenna, based on the broadband leaky concept. The pyramid antenna, currently covered by a patent application,

  14. A head and neck hyperthermia applicator: Theoretical antenna array design

    NARCIS (Netherlands)

    Paulides, M.M.; Bakker, J.F.; Zwamborn, A.P.M.; Rhoon, G.C. van

    2007-01-01

    Purpose: Investigation into the feasibility of a circular array of dipole antennas to deposit RF-energy centrally in the neck as a function of: 1) patient positioning, 2) antenna ring radius, 3) number of antenna rings, 4) number of antennas per ring and 5) distance between antenna rings. Materials

  15. A head and neck hyperthermia applicator: Theoretical antenna array design

    NARCIS (Netherlands)

    M.M. Paulides (Margarethus); J.F. Bakker (Jurriaan); A.P.M. Zwamborn; G.C. van Rhoon (Gerard)

    2007-01-01

    textabstractPurpose: Investigation into the feasibility of a circular array of dipole antennas to deposit RF-energy centrally in the neck as a function of: (1) patient positioning, (2) antenna ring radius, (3) number of antenna rings, (4) number of antennas per ring and (5) distance between antenna

  16. 47 CFR 73.316 - FM antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false FM antenna systems. 73.316 Section 73.316... Broadcast Stations § 73.316 FM antenna systems. (a) It shall be standard to employ horizontal polarization...) Directional antennas. A directional antenna is an antenna that is designed or altered for the purpose...

  17. 47 CFR 22.365 - Antenna structures; air navigation safety.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Antenna structures; air navigation safety. 22... Antenna structures; air navigation safety. Licensees that own their antenna structures must not allow these antenna structures to become a hazard to air navigation. In general, antenna structure owners...

  18. Membrane Shell Reflector Segment Antenna

    Science.gov (United States)

    Fang, Houfei; Im, Eastwood; Lin, John; Moore, James

    2012-01-01

    The mesh reflector is the only type of large, in-space deployable antenna that has successfully flown in space. However, state-of-the-art large deployable mesh antenna systems are RF-frequency-limited by both global shape accuracy and local surface quality. The limitations of mesh reflectors stem from two factors. First, at higher frequencies, the porosity and surface roughness of the mesh results in loss and scattering of the signal. Second, the mesh material does not have any bending stiffness and thus cannot be formed into true parabolic (or other desired) shapes. To advance the deployable reflector technology at high RF frequencies from the current state-of-the-art, significant improvements need to be made in three major aspects: a high-stability and highprecision deployable truss; a continuously curved RF reflecting surface (the function of the surface as well as its first derivative are both continuous); and the RF reflecting surface should be made of a continuous material. To meet these three requirements, the Membrane Shell Reflector Segment (MSRS) antenna was developed.

  19. Curved spiral antennas for underwater biological applications

    Science.gov (United States)

    Llamas, Ruben

    We developed curved spiral antennas for use in underwater (freshwater) communications. Specifically, these antennas will be integrated in so-called mussel backpacks. Backpacks are compact electronics that incorporate sensors and a small radio that operate around 300 MHz. Researchers attach these backpacks in their freshwater mussel related research. The antennas must be small, lightweight, and form-fit the mussel. Additionally, since the mussel orientation is unknown, the antennas must have broad radiation patterns. Further, the electromagnetic environment changes significantly as the mussels burrow into the river bottom. Broadband antennas, such a spiral antennas, will perform better in this instance. While spiral antennas are well established, there has been little work on their performance in freshwater. Additionally, there has been some work on curved spiral antennas, but this work focused on curving in one dimension, namely curving around a cylinder. In this thesis we develop spiral antennas that curve in two dimensions in order to conform the contour of a mussel's shell. Our research has three components, namely (a) an investigation of the relevant theoretical underpinning of spiral antennas, (b) extensive computer simulations using state-of-the art computational electromagnetics (CEM) simulation software, and (c) experimental validation. The experimental validation was performed in a large tank in a laboratory setting. We also validated some designs in a pool (~300,000 liters of water and ~410 squared-meter dive pool) with the aid of a certified diver. To use CEM software and perform successful antenna-related experiments require careful attention to many details. The mathematical description of radiation from an antenna, antenna input impedance and so on, is inherently complex. Engineers often make simplifying assumptions such as assuming no reflections, or an isotropic propagation environment, or operation in the antenna far field, and so on. This makes

  20. Compact Miniaturized Antenna for 210 MHz RFID

    Science.gov (United States)

    Lee, Richard Q.; Chun, Kue

    2008-01-01

    This paper describes the design and simulation of a miniaturized square-ring antenna. The miniaturized antenna, with overall dimensions of approximately one tenth of a wavelength (0.1 ), was designed to operate at around 210 MHz, and was intended for radio-frequency identification (RFID) application. One unique feature of the design is the use of a parasitic element to improve the performance and impedance matching of the antenna. The use of parasitic elements to enhance the gain and bandwidth of patch antennas has been demonstrated and reported in the literature, but such use has never been applied to miniaturized antennas. In this work, we will present simulation results and discuss design parameters and their impact on the antenna performance.

  1. Metamaterial Embedded Wearable Rectangular Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    J. G. Joshi

    2012-01-01

    Full Text Available This paper presents an indigenous low-cost metamaterial embedded wearable rectangular microstrip patch antenna using polyester substrate for IEEE 802.11a WLAN applications. The proposed antenna resonates at 5.10 GHz with a bandwidth and gain of 97 MHz and 4.92 dBi, respectively. The electrical size of this antenna is 0.254λ×0.5λ. The slots are cut in rectangular patch to reduce the bending effect. This leads to mismatch the impedance at WLAN frequency band; hence, a metamaterial square SRR is embedded inside the slot. A prototype antenna has been fabricated and tested, and the measured results are presented in this paper. The simulated and measured results of the proposed antenna are found to be in good agreement. The bending effect on the performance of this antenna is experimentally verified.

  2. Microfluidic serpentine antennas with designed mechanical tunability.

    Science.gov (United States)

    Huang, YongAn; Wang, Yezhou; Xiao, Lin; Liu, Huimin; Dong, Wentao; Yin, Zhouping

    2014-11-07

    This paper describes the design and characterization of microfluidic serpentine antennas with reversible stretchability and designed mechanical frequency modulation (FM). The microfluidic antennas are designed based on the Poisson's ratio of the elastomer in which the liquid alloy antenna is embedded, to controllably decrease, stabilize or increase its resonance frequency when being stretched. Finite element modelling was used in combination with experimental verification to investigate the effects of substrate dimensions and antenna aspect ratios on the FM sensitivity to uniaxial stretching. It could be designed within the range of -1.2 to 0.6 GHz per 100% stretch. When the aspect ratio of the serpentine antenna is between 1.0 and 1.5, the resonance frequency is stable under stretching, bending, and twisting. The presented microfluidic serpentine antenna design could be utilized in the field of wireless mobile communication for the design of wearable electronics, with a stable resonance frequency under dynamic applied strain up to 50%.

  3. VAlidation STandard antennas: Past, present and future

    DEFF Research Database (Denmark)

    Drioli, Luca Salghetti; Ostergaard, A; Paquay, M

    2011-01-01

    The field of antenna measurements is lacking a Golden Standard, i.e. an antenna of which the pattern is known by definition. To gain confidence in the performance of a range, including the procedures and skills of the operators, range comparison has been a popular tool for over three decades...... designed for validation campaigns of antenna measurement ranges. The driving requirements of VAST antennas are their mechanical stability over a given operational temperature range and with respect to any orientation of the gravity field. The mechanical design shall ensure extremely stable electrical...... characteristics allowing frequent travel and shall ease the handling of the VAST antenna (practical electrical and mechanical interfaces, well-defined alignment tools, low mass, attachment points for lifting, etc). The widespread use of the so-called VAST-12 antenna demonstrates the long-term value of dedicated...

  4. Millimeter-wave antennas configurations and applications

    CERN Document Server

    du Preez, Jaco

    2016-01-01

    This book comprehensively reviews the state of the art in millimeter-wave antennas, traces important recent developments and provides information on a wide range of antenna configurations and applications. While fundamental theoretical aspects are discussed whenever necessary, the book primarily focuses on design principles and concepts, manufacture, measurement techniques, and practical results. Each of the various antenna types scalable to millimeter-wave dimensions is considered individually, with coverage of leaky-wave and surface-wave antennas, printed antennas, integrated antennas, and reflector and lens systems. The final two chapters address the subject from a systems perspective, providing an overview of supporting circuitry and examining in detail diverse millimeter-wave applications, including high-speed wireless communications, radio astronomy, and radar. The vast amount of information now available on millimeter-wave systems can be daunting for researchers and designers entering the field. This b...

  5. A small sensor with matched optical antenna

    Energy Technology Data Exchange (ETDEWEB)

    Shepelev, A.V. [Russian Academy of Sciences, Moscow (Russian Federation). Central Design Bureau for Unique Instrumentation

    1994-12-31

    Each device for radiation registration in the radio range contains an antenna. Mainly it is the antenna dimension that determines the sensitivity of the device. Can an antenna for the registration of more short wave radiation be constructed? The main feature of antenna action is the conversion of the incident radiation mode into the mode passing through the antenna. At this moment the radiation brightness (which is equivalent to a number of photons per mode) can increase. In accordance with the geometric optics (Shtraubel theorem) the length and mirror systems cannot raise the radiation brightness in principle and cannot be treated as an antenna. Recently it was established that definite optical processes and systems give a possibility of increasing the full radiation brightness. The device for effective registration of short wave radiation is worked out on the basis of these processes.

  6. Smart Antenna for Cellular Mobile Communication

    CERN Document Server

    Jain, R K; Agrawal, N K

    2012-01-01

    The adoption of smart / adaptive antenna techniques in future wireless systems is expected to have a significant impact on the efficient use of the spectrum, the minimization of the cost of establishing new wireless networks, the optimization of service quality and realization of transparent operation across multi technology wireless networks [1]. This paper presents brief account on smart antenna (SA) system. SAs can place nulls in the direction of interferers via adaptive updating of weights linked to each antenna element. SAs thus cancel out most of the co-channel interference resulting in better quality of reception and lower dropped calls. SAs can also track the user within a cell via direction of arrival algorithms [2]. This paper explains the architecture, evolution and how the smart / adaptive antenna differs from the basic format of antenna. The paper further explains about the radiation pattern of the antenna and why it is highly preferred in its relative field. The capabilities of smart / adaptive ...

  7. Miniaturized Planar Split-Ring Resonator Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    A miniaturized planar antenna based on a broadside-coupled split ring resonator excited by an arc-shaped dipole is presented. The excitation dipole acts as a small tuning capacitor in series with a parallel RLC circuit represented by the SRR. The antenna resonance frequency and dimensions...... a essentially determined by the SRR, while by varying the dipole arm length the input resistance is changed in a wide range, thus matching the antenna to a feed line and compensating for simulation and manufacturing inaccuracies. No additional matching network is required. Theoretically, there is no limit...... on how small this antenna can be. In practice, the lower bound is set by losses in utilized materials and manufacturing inaccuracies. As an example, an antenna of ka=0.09 was designed, fabricated and tested. Although the initially fabricated antenna prototype had the input impedance of 43 ohms...

  8. New band-notched UWB antenna

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-xiang; DENG Hong-wei

    2009-01-01

    A simple and compact ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper. The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded on each arm of the similar U-shaped radiator. The impedance bandwidth of the antenna overlap with IEEE 802.11a is rejected consequently. The geometry parameters of the antenna are investigated and optimized with HFSS. The measured bandwidth of the proposed antenna occupies about 7.89 GHz covering from 3.05 GHz to 10.94 GHz with expected notched band from 4.96 GHz to 5.98 GHz. A quasi-omnidirectional and quasi-symmetrical radiation pattern in the whole band is also obtained. As a result, a UWB wireless communication system can be simplified with the band-notched UWB antenna presented.

  9. Novel Electrically Small Spherical Electric Dipole Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2010-01-01

    This paper introduces a novel electrically small spherical meander antenna. Horizontal sections of the meander are composed of wire loops, radii of which are chosen so that the whole structure is conformal to a sphere of radius a. To form the meander the loops are connected by wires at a meridian...... plane. The antenna operates as an electric dipole, i.e. it radiates the TM10 spherical mode. The antenna is self-resonant and can be matched to a wide range of input feed lines without an external matching network. In this paper, a spherical meander antenna of the size ka = 0.27 and the input impedance...... of 72 ohms is numerically investigated and its performance is compared to that of the multiarm spherical helix antenna of the same size. Both antennas yield equal quality factors, which are about 1.5 times the Chu lower bound, but quite different cross-polarization characteristics....

  10. Mobile satellite communications - Vehicle antenna technology update

    Science.gov (United States)

    Bell, D.; Naderi, F. M.

    1986-01-01

    This paper discusses options for vehicle antennas to be used in mobile satellite communications systems. Two types of antennas are identified. A non-steerable, azimuthally omnidirectional antenna with a modest gain of 3 to 5 dBi is suggested when a low cost is desired. Alternatively, mechanically or electronically steerable antennas with a higher gain of 10 to 12 dBi are suggested to alleviate power and spectrum scarcity associated with mobile satellite communications. For steerable antennas, both open-loop and closed-loop pointing schemes are discussed. Monopulse and sequential lobing are proposed for the mechanically steered and electronically steered antennas, respectively. This paper suggests a hybrid open-loop/closed-loop pointing technique as the best performer in the mobile satellite environment.

  11. Spherical near-field antenna measurements — The most accurate antenna measurement technique

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2016-01-01

    The spherical near-field antenna measurement technique combines several advantages and generally constitutes the most accurate technique for experimental characterization of radiation from antennas. This paper/presentation discusses these advantages, briefly reviews the early history and present...... status, and addresses future challenges for spherical near-field antenna measurements; in particular, from the viewpoint of the DTU-ESA Spherical Near-Field Antenna Test Facility....

  12. Ultrawideband antennas for microwave imaging systems

    CERN Document Server

    Denidni, Tayeb A

    2014-01-01

    This book presents ultrawideband antennas and their applications on microwave imaging. The chapters focus on recent techniques, analysis, and applications along with the future vision of this emerging field of applied electromagnetics. Several emerging topics are essayed, including dielectric resonator antennas and planar ultrawideband antennas for microwave imaging.This resource incorporates modern design concepts, analysis, and optimization techniques based on recent developments. Readers are also provided with an extensive overview of current regulations, including those related to microwav

  13. International Mapping of Antenna-Measurement Facilities

    DEFF Research Database (Denmark)

    Boccia, Luigi; Breinbjerg, Olav; Di Massa, Giuseppe;

    2006-01-01

    This paper presents a comprehensive international mapping of antenna-measurement facilities. This initiative, conducted within the framework of the Antenna Centre of Excellence (ACE) of the European Union, is oriented toward all institutions having research, development, or operational activities...... measurements, in particular from the wireless communication industry, to identify and contact antenna-measurement facilities. The first phase of the mapping showed a significant and encouraging reaction to this initiative, with more than 50 European facilities currently registered. The next phase aims...

  14. Quasi-optical slot antenna SIS mixers

    OpenAIRE

    Zmuidzinas, Jonas; LeDuc, H. G.

    1992-01-01

    A quasi-optical SIS mixer designed for efficient radiation coupling is described. The mixer uses a twin-slot antenna which has the advantages of a good beam pattern and a low impedance. The radiation and impedance characteristics of the antenna were obtained from a moment-matched calculation. Tapered superconducting microstrip transmission lines are used to carry the radiation from the slot antennas to the tunnel junction. The effective impedance seen by the tunnel junction is quite low, abou...

  15. Quadric Resistive Sheet Profile for Wideband Antennas

    Directory of Open Access Journals (Sweden)

    Z. Raida

    2007-09-01

    Full Text Available A new type of a nonreflecting resistive dipole antenna with quadric continuous resistivity profile is presented in this paper. The antenna is mathematically described and compared with the antenna originally proposed by Wu and King. The verification of a proposed theory and the comparison between Wu-King and quadric profile are carried out by simulation models that were designed for this purpose. The attention is turned to the proper attenuation of a wave excited on the resistive sheet, especially.

  16. Multi-Mode Broadband Patch Antenna

    Science.gov (United States)

    Romanofsky, Robert R. (Inventor)

    2001-01-01

    A multi-mode broad band patch antenna is provided that allows for the same aperture to be used at independent frequencies such as reception at 19 GHz and transmission at 29 GHz. Furthermore, the multi-mode broadband patch antenna provides a ferroelectric film that allows for tuning capability of the multi-mode broadband patch antenna over a relatively large tuning range. The alternative use of a semiconductor substrate permits reduced control voltages since the semiconductor functions as a counter electrode.

  17. An analysis technique for microstrip antennas

    Science.gov (United States)

    Agrawal, P. K.; Bailey, M. C.

    1977-01-01

    The paper presents a combined numerical and empirical approach to the analysis of microstrip antennas over a wide range of frequencies. The method involves representing the antenna by a fine wire grid immersed in a dielectric medium and then using Richmond's reaction formulation (1974) to evaluate the piecewise sinusoidal currents on the grid segments. The calculated results are then modified to account for the finite dielectric discontinuity. The method is applied to round and square microstrip antennas.

  18. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Christodoulou, Christos George (The University of New Mexico, Albuquerque, NM); Nordquist, Christopher Daniel; Feldner, Lucas Matthew

    2005-07-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  19. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Nordquist, Christopher Daniel; Christodoulou, Christos George (University of New Mexico, Albuquerque, NM); Feldner, Lucas Matthew

    2005-01-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  20. Carbon Nanotube Thin-Film Antennas.

    Science.gov (United States)

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

  1. Three-dimensional winged nanocone optical antennas.

    Science.gov (United States)

    Huttunen, Mikko J; Lindfors, Klas; Andriano, Domenico; Mäkitalo, Jouni; Bautista, Godofredo; Lippitz, Markus; Kauranen, Martti

    2014-06-15

    We introduce 3D optical antennas based on winged nanocones. The antennas support particle plasmon oscillations with current distributions that facilitate transformation of transverse far-field radiation to strong longitudinal local fields near the cone apices. We characterize the optical responses of the antennas by their extinction spectra and by second-harmonic generation microscopy with cylindrical vector beams. The results demonstrate a new 3D polarization-controllable optical antenna for applications in apertureless near-field microscopy, spectroscopy, and plasmonic sensing.

  2. Handbook of smart antennas for RFID systems

    CERN Document Server

    2010-01-01

    The Handbook of Smart Antennas for RFID Systems is a single comprehensive reference on the smart antenna technologies applied to RFID. This book will provide a timely reference book for researchers and students in the areas of both smart antennas and RFID technologies. It is the first book to combine two of the most important wireless technologies together in one book. The handbook will feature chapters by leading experts in both academia and industry offering an in-depth description of terminologies and concepts related to smart antennas in various RFID systems applications.

  3. Wideband Monopole Antenna for WLAN Applications

    Directory of Open Access Journals (Sweden)

    Muhammad Umar

    2013-03-01

    Full Text Available This paper presents a circular patch antenna for WLAN applications with wideband characteristics. It is shown that impedance of the antenna is matched over wideband by using the partial ground plane and quarter wave transformer with slotted TX-Line. Ansoft HFSS is used for simulation tool to map the numerical results for the return loss frequency behavior of antenna. Measure of bandwidth, return loss and radiation pattern are also reported with satisfactory performance. As the patch is circular in shape so substrate is kept in the same shape. The shape of the substrate is also discussed in details for specific antenna designs.

  4. A COMPACT CIRCULARLY POLARIZED SLOTTED MICROSTRIP ANTENNA

    Directory of Open Access Journals (Sweden)

    V. Jebaraj

    2014-12-01

    Full Text Available Slot antennas are often used at UHF and microwave frequencies. In slot antenna for RFID reader applications the frequency ranges from 902-923MHz to achieve circular polarization. The shapes and size of the slot, as well as the driving frequency, determine the radiation distribution pattern. The proposed compact size circularly polarized slotted microstrip antenna are summarized with design rules. The circularly polarized radiation in square patch antenna can be obtained by perturbation technique with different shapes of slot in the orthogonal direction. A single feed configuration based symmetric slotted microstrip antenna is adapted to realize the compact circularly polarized microstrip antennas. Based on the perimeter, the size of the slot on microstrip slot antenna are studied and compared. The Operating frequency of the antenna is 912MHz that can be tuned by varying the perimeter of the slot while the keeping the circularly polarized radiation unchanged. The schematic and layout are configured by using Advanced Design System (ADS. Return loss, Resonant Frequency, Axial Ratio (AR, and Gain were determined for the proposed system using ADS. A measured 3dB Axial Ratio (AR bandwidth around 6MHz with 16MHz impedance bandwidth has been achieved for the antenna on a RO3004C substrate with dielectric constant 3.38.

  5. Vivaldi Antenna for RF Energy Harvesting

    Directory of Open Access Journals (Sweden)

    J. Schneider

    2016-12-01

    Full Text Available Energy harvesting is a future technology for capturing ambient energy from the environment to be recycled to feed low-power devices. A planar antipodal Vivaldi antenna is presented for gathering energy from GSM, WLAN, UMTS and related applications. The designed antenna has the potential to be used in energy harvesting systems. Moreover, the antenna is suitable for UWB applications, because it operates according to FCC regulations (3.1 – 10.6 GHz. The designed antenna is printed on ARLON 600 substrate and operates in frequency band from 0.810 GHz up to more than 12 GHz. Experimental results show good conformity with simulated performance.

  6. Antennas with non-foster matching networks

    CERN Document Server

    Aberle, James T

    2007-01-01

    Most antenna engineers are likely to believe that antennas are one technology that is more or less impervious to the rapidly advancing semiconductor industry. However, as demonstrated in this lecture, there is a way to incorporate active components into an antenna and transform it into a new kind of radiating structure that can take advantage of the latest advances in analog circuit design. The approach for making this transformation is to make use of non-Foster circuit elements in the matching network of the antenna. By doing so, we are no longer constrained by the laws of physics that apply

  7. U-Slotted Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    Yogesh Bhomia

    2013-05-01

    Full Text Available A new U–slotted microstrip antenna is proposed. A patch antenna is a narrowband, wide-beam antenna These antennas are low profile, conformal to planar and non-planar surface, simple and inexpensive to manufacture using modern printed circuit technology, mechanically robust when mounted on rigid surface, compatible with MMIC designs and when the particular shape and mode are selected they are very versatile in terms of resonant frequency, polarization, field pattern and impedance. Microstrip antenna consist of a very thin metallic strip (patch placed a small fraction of a wavelength above a ground plane. The patch is generally made of conducting material such as copper or gold and can take any possible shape. This paper presents a design of U - slotted microstrip patch antenna and experimentally studied on IE3D software. This design is achieved by cutting U shape in a patch. With U - slotted shapes patch antenna is designed on a FR4 substrate of thickness 1.524 mm and relative permittivity of 4.4 and mounted above the ground plane at a height of 6 mm. Bandwidth as high as 39% are achieved with stable pattern characteristics, such as gain and cross polarization, within its bandwidth. Impedance bandwidth, antenna gain and return loss are observed for the proposed antenna. Details of the measured and simulated results are presented and discussed

  8. A Design of Double Broadband MIMO Antenna

    Directory of Open Access Journals (Sweden)

    Yanfeng Geng

    2015-01-01

    Full Text Available The MIMO antenna applied to LTE mobile system should be miniaturization and can work in the current communication frequency band; isolation between each antenna unit also should be good so as to reduce loss of radio wave energy and improve the antenna performance of the MIMO system. This paper puts forward the design scheme of a broadband MIMO double antenna. And the design of antenna unit and debugging and related technical measures, such as bending antenna bracket, are both presented; the integration design of high isolation of ultra broadband MIMO antenna is realized on the plate with the volume of 100 × 52 × 0.8 mm3; antenna working bands are 698 MHz~960 MHz and 1710 MHz~2700 MHz; in the whole spectrum, the 10 dB of port isolation can be basically achieved; in low frequency band, the isolation degree of antenna port can reach 12 dB.

  9. Whip antenna design for portable rf systems

    Science.gov (United States)

    Ponnapalli, Saila; Canora, Frank J.

    1995-12-01

    Whip type antennas are probably the most commonly used antennas in portable rf systems, such as cordless and cellular phones, rf enabled laptop computers, personal digital assistants (PDAs), and handheld computers. Whip antennas are almost always mounted on the chassis which contains the radio and other electronics. The chassis is usually a molded plastic which is coated with a conducting paint for EMI purposes. The chassis which appears as a lossy conductor to the antenna, has several effects -- detuning, altering the gain of the antenna, and shadowing its radiation pattern. Extensive modeling and measurements must be performed in order to fully characterize the affects of the chassis on the whip antenna, and to optimize antenna type, orientation and position. In many instances, modeling plays a more important role in prediction of the performance of whip antennas, since measurements become difficult due to the presence of common mode current on feed cables. In this paper models and measurements are used to discuss the optimum choice of whip antennas and the impact of the chassis on radiation characteristics. A modeling tool which has been previously described and has been successfully used to predict radiated field patterns is used for simulations, and measured and modeled results are shown.

  10. Considerations for millimeter wave printed antennas

    Science.gov (United States)

    Pozar, D. M.

    1983-01-01

    Calculated data are presented on the performance of printed antenna elements on substrates which may be electrically thick, as would be the case for printed antennas at millimeter wave frequencies. Printed dipoles and microstrip patch antennas on polytetrafluoroethylene (PTFE), quartz, and gallium arsenide substrates are considered. Data are given for resonant length, resonant resistance, bandwidth, loss due to surface waves, loss due to dielectric heating, and mutual coupling. Also presented is an optimization procedure for maximizing or minimizing power launched into surface waves from a multielement printed antenna array. The data are calculated by a moment method solution.

  11. Gigahertz-band electronically scanned antennas

    Science.gov (United States)

    Bei, Nikolai A.

    2000-12-01

    Foundation and principles of radio lenses construction of centimeter and millimeter wave ranges with controlled refracting index, combining the quality of phased array antennas with optical devices are stated. Possibilities of the electronically scanning with wide-angle sector and high gain are maintained. Construction principles of scanning antennas with controlled lenses, combining the quality of phased array antennas with optical devices, are stated. Possibilities of electronically scanning with broad angle sector and high gain are maintained. Some examples of construction of antennas millimeter range of waves are listed here.

  12. Resonance spectra of diabolo optical antenna arrays

    Science.gov (United States)

    Guo, Hong; Simpkins, Blake; Caldwell, Joshua D.; Guo, Junpeng

    2015-10-01

    A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  13. Resonance spectra of diabolo optical antenna arrays

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hong; Guo, Junpeng, E-mail: guoj@uah.edu [Department of Electrical and Computer Engineering, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Simpkins, Blake; Caldwell, Joshua D. [Naval Research Laboratory, 4555 Overlook Ave., SW Washington, DC 20375 (United States)

    2015-10-15

    A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  14. A Compact Diversity Antenna for Handheld Terminals

    Institute of Scientific and Technical Information of China (English)

    Hai-Lin Xiao; Zai-Ping Nie; Yu-Jing Wu

    2009-01-01

    The handheld terminals antenna should have a small size, sufficient gain and big bandwidth. In this paper, a compact planar inverted-L diversity antenna for handheld terminals is proposed. Three diversity antennas operating at 2.15 GHz are designed and the effect of important parameters of the proposed antenna is measured. The isolation is found to be better than 13 dB, the usable bandwidth is about 13%. Moreover, the measured radiation patterns are also obtained that the backward radiation is decreased.

  15. Analysis on two novel spherical helical antennas

    Institute of Scientific and Technical Information of China (English)

    Hou ZHANG; Yingzeng YIN; Dongyu XIA

    2009-01-01

    Two novel spherical helical antennas are designed by projecting the planar equiangular spiral antenna onto hemisphere and partial sphere surfaces.Their radiation properties are analyzed by the moment method with curved basis and test function,and the curves of the voltage standing wave ratio (VSWR),gain,polarization and pattern that change with frequency are also given,respectively.It can be seen that the circular polarization band of the novel hemispherical helical antenna is broader.The gain curve of the partial spherical helical antenna is flatter and the structure is simpler.

  16. Antenna technology for advanced mobile communication systems

    Science.gov (United States)

    Rammos, Emmanuel; Roederer, Antoine; Rogard, Roger

    1988-01-01

    The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources.

  17. Improved patch antenna performance by using a metamaterial cover

    Institute of Scientific and Technical Information of China (English)

    ZHU Fang-ming; HU Jun

    2007-01-01

    A new patch antenna system with a metamaterial cover is presented in this paper. The impedance, radiation pattern, and directivity of such an antenna are studied. A performance comparison between the conventional patch antenna and the new metamaterial patch antenna is given. The results show that the directivity of the metamaterial patch antenna is significantly improved. The effect of the metamaterial cover's layer numbers on the radiation pattern of the patch antenna is also studied.

  18. Phased array antenna element for automotive radar application

    OpenAIRE

    2014-01-01

    In this thesis work, a design of reliable antenna front-end for W band automotive radar is studied and the problems and considerations associated with phased array antenna design at W-band are addressed. Proposed phased array antenna consists of on chip patch antenna which has the advantages of being integrated by the active circuitry. A sample of patch antenna and patch array are designed and fabricated to be tested for their functionality. Printing antenna on Silicon substrate is a compact ...

  19. Magnetic antenna excitation of whistler modes. IV. Receiving antennas and reciprocity

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L., E-mail: stenzel@physics.ucla.edu; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2015-07-15

    Antenna radiation patterns are an important property of antennas. Reciprocity holds in free space and the radiation patterns for exciting and receiving antennas are the same. In anisotropic plasmas, radiation patterns are complicated by the fact that group and phase velocities differ and certain wave properties like helicity depend on the direction of wave propagation with respect to the background magnetic field B{sub 0}. Interference and wave focusing effects are different than in free space. Reciprocity does not necessarily hold in a magnetized plasma. The present work considers the properties of various magnetic antennas used for receiving whistler modes. It is based on experimental data from exciting low frequency whistler modes in a large uniform laboratory plasma. By superposition of linear waves from different antennas, the radiation patterns of antenna arrays are derived. Plane waves are generated and used to determine receiving radiation patterns of different receiving antennas. Antenna arrays have radiation patterns with narrow lobes, whose angular position can be varied by physical rotation or electronic phase shifting. Reciprocity applies to broadside antenna arrays but not to end fire arrays which can have asymmetric lobes with respect to B{sub 0}. The effect of a relative motion between an antenna and the plasma has been modeled by the propagation of a short wave packet moving along a linear antenna array. An antenna moving across B{sub 0} has a radiation pattern characterized by an oscillatory “whistler wing.” A receiving antenna in motion can detect any plane wave within the group velocity resonance cone. The radiation pattern also depends on loop size relative to the wavelength. Motional effects prevent reciprocity. The concept of the radiation pattern loses its significance for wave packets since the received signal does not only depend on the antenna but also on the properties of the wave packet. The present results are of fundamental

  20. Breadboard Signal Processor for Arraying DSN Antennas

    Science.gov (United States)

    Jongeling, Andre; Sigman, Elliott; Chandra, Kumar; Trinh, Joseph; Soriano, Melissa; Navarro, Robert; Rogstad, Stephen; Goodhart, Charles; Proctor, Robert; Jourdan, Michael; Rayhrer, Benno

    2008-01-01

    A recently developed breadboard version of an advanced signal processor for arraying many antennas in NASA s Deep Space Network (DSN) can accept inputs in a 500-MHz-wide frequency band from six antennas. The next breadboard version is expected to accept inputs from 16 antennas, and a following developed version is expected to be designed according to an architecture that will be scalable to accept inputs from as many as 400 antennas. These and similar signal processors could also be used for combining multiple wide-band signals in non-DSN applications, including very-long-baseline interferometry and telecommunications. This signal processor performs functions of a wide-band FX correlator and a beam-forming signal combiner. [The term "FX" signifies that the digital samples of two given signals are fast Fourier transformed (F), then the fast Fourier transforms of the two signals are multiplied (X) prior to accumulation.] In this processor, the signals from the various antennas are broken up into channels in the frequency domain (see figure). In each frequency channel, the data from each antenna are correlated against the data from each other antenna; this is done for all antenna baselines (that is, for all antenna pairs). The results of the correlations are used to obtain calibration data to align the antenna signals in both phase and delay. Data from the various antenna frequency channels are also combined and calibration corrections are applied. The frequency-domain data thus combined are then synthesized back to the time domain for passing on to a telemetry receiver

  1. Enabling Technologies for Fabrication of Large Area Flexible Antennas Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flexible, foldable, and/or inflatable antenna systems open up a wealth of opportunities. Integrating antenna elements and related electronics onto flexible...

  2. Experimental application of QCD antennas

    Energy Technology Data Exchange (ETDEWEB)

    Bobrovskyi, Sergei

    2010-02-15

    A serious problem in searches for new physics at the LHC is the rejection of QCD induced multijet events. In this thesis the formalism of QCD antenna variables based on the SPHEL approximation of QCD matrix elements is applied for the rst time on experimentally reconstructed jets in order to discriminate QCD from supersymmetric processes. The new observables provide additional information with respect to traditional event shape variables. Albeit correlated with experimentally measured missing transverse energy, the variables can be used to improve the signal to background ratio. (orig.)

  3. Antenna allocation in MIMO radar with widely separated antennas for multi-target detection.

    Science.gov (United States)

    Gao, Hao; Wang, Jian; Jiang, Chunxiao; Zhang, Xudong

    2014-10-27

    In this paper, we explore a new resource called multi-target diversity to optimize the performance of multiple input multiple output (MIMO) radar with widely separated antennas for detecting multiple targets. In particular, we allocate antennas of the MIMO radar to probe different targets simultaneously in a flexible manner based on the performance metric of relative entropy. Two antenna allocation schemes are proposed. In the first scheme, each antenna is allocated to illuminate a proper target over the entire illumination time, so that the detection performance of each target is guaranteed. The problem is formulated as a minimum makespan scheduling problem in the combinatorial optimization framework. Antenna allocation is implemented through a branch-and-bound algorithm and an enhanced factor 2 algorithm. In the second scheme, called antenna-time allocation, each antenna is allocated to illuminate different targets with different illumination time. Both antenna allocation and time allocation are optimized based on illumination probabilities. Over a large range of transmitted power, target fluctuations and target numbers, both of the proposed antenna allocation schemes outperform the scheme without antenna allocation. Moreover, the antenna-time allocation scheme achieves a more robust detection performance than branch-and-bound algorithm and the enhanced factor 2 algorithm when the target number changes.

  4. Wireless SAW Sensors Having Integrated Antennas

    Science.gov (United States)

    Gallagher, Mark (Inventor); Malocha, Donald C. (Inventor)

    2015-01-01

    A wireless surface acoustic wave sensor includes a piezoelectric substrate, a surface acoustic wave device formed on the substrate, and an antenna formed on the substrate. In some embodiments, the antenna is formed on the surface of the substrate using one or more of photolithography, thin film processing, thick film processing, plating, and printing.

  5. Juno Microwave Radiometer Patch Array Antennas

    Science.gov (United States)

    Chamberlain, N.; Chen, J.; Focardi, P.; Hodges, R.; Hughes, R.; Jakoboski, J.; Venkatesan, J.; Zawadzki, M.

    2009-01-01

    Juno is a mission in the NASA New Frontiers Program with the goal of significantly improving our understanding of the formation and structure of Jupiter. This paper discusses the modeling and measurement of the two patch array antennas. An overview of the antenna architecture, design and development at JPL is provided, along with estimates of performance and the results of measurements.

  6. Multiple Antennas Arm Effective MIMO Systems

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2007-01-01

    Understanding the interactions among different combinations of receive and transmit antenna elements can help increase the capacity of cellular wireless systems.......Understanding the interactions among different combinations of receive and transmit antenna elements can help increase the capacity of cellular wireless systems....

  7. Fresnel zones for ground-based antennas

    DEFF Research Database (Denmark)

    Andersen, J. Bach

    1964-01-01

    The ordinary Fresnel zone concept is modified to include the influence of finite ground conductivity. This is important for ground-based antennas because the influence on the radiation pattern of irregularities near the antenna is determined by the amplitude and phase of the groundwave. A new...

  8. Antenna impedance matching with neural networks.

    Science.gov (United States)

    Hemminger, Thomas L

    2005-10-01

    Impedance matching between transmission lines and antennas is an important and fundamental concept in electromagnetic theory. One definition of antenna impedance is the resistance and reactance seen at the antenna terminals or the ratio of electric to magnetic fields at the input. The primary intent of this paper is real-time compensation for changes in the driving point impedance of an antenna due to frequency deviations. In general, the driving point impedance of an antenna or antenna array is computed by numerical methods such as the method of moments or similar techniques. Some configurations do lend themselves to analytical solutions, which will be the primary focus of this work. This paper employs a neural control system to match antenna feed lines to two common antennas during frequency sweeps. In practice, impedance matching is performed off-line with Smith charts or relatively complex formulas but they rarely perform optimally over a large bandwidth. There have been very few attempts to compensate for matching errors while the transmission system is in operation and most techniques have been targeted to a relatively small range of frequencies. The approach proposed here employs three small neural networks to perform real-time impedance matching over a broad range of frequencies during transmitter operation. Double stub tuners are being explored in this paper but the approach can certainly be applied to other methodologies. The ultimate purpose of this work is the development of an inexpensive microcontroller-based system.

  9. Structures for remotely deployable precision antennas

    Science.gov (United States)

    Hedgepeth, J. M.

    1989-01-01

    Future space missions such as the Earth Science Geostationary Platform (ESGP) will require highly accurate antennas with apertures that cannot be launched fully formed. The operational orbits are often inaccessible to manned flight and will involve expendable launch vehicles such as the Delta or Titan. There is therefore a need for completely deployable antenna reflectors of large size capable of efficiently handling millimeter wave electromagnetic radiation. The parameters for the type of mission are illustrated. The logarithmic plot of frequency versus aperture diameter shows the regions of interest for a large variety of space antenna applications, ranging from a 1500-meter-diameter radio telescope for low frequencies to a 20-meter-diameter infrared telescope. For the ESGP, a major application is the microwave radiometry at high frequencies for atmospheric sounding. Almost all existing large antenna reflectors for space employ a mesh-type reflecting surface. Examples are shown and discussed which deal with the various structural concepts for mesh antennas. Fortunately, those concepts are appropriate for creating the very large apertures required at the lower frequencies for good resolution. The emphasis is on the structural concepts and technologies that are appropriate to fully automated deployment of dish-type antennas with solid reflector surfaces. First the structural requirements are discussed. Existing concepts for fully deployable antennas are then described and assessed relative to the requirements. Finally, several analyses are presented that evaluate the effects of beam steering and segmented reflector design on the accuracy of the antenna.

  10. Calculating Electromagnetic Fields Of A Loop Antenna

    Science.gov (United States)

    Schieffer, Mitchell B.

    1987-01-01

    Approximate field values computed rapidly. MODEL computer program developed to calculate electromagnetic field values of large loop antenna at all distances to observation point. Antenna assumed to be in x-y plane with center at origin of coordinate system. Calculates field values in both rectangular and spherical components. Also solves for wave impedance. Written in MicroSoft FORTRAN 77.

  11. Synthesis of Phased Cylindrical Arc Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Hussein Rammal

    2009-01-01

    Full Text Available This paper describes a new approach to synthesize cylindrical antenna arrays controlled by the phase excitation, to synthesize directive lobe and multilobe patterns with steered zero. The proposed method is based on iterative minimization of a function that incorporates constraints imposed in each direction. An 8-element cylindrical antenna has been simulated and tested for various types of beam configurations.

  12. Antenna Diagnostics using Near Field Techniques

    NARCIS (Netherlands)

    Paquay, M.H.A.

    1996-01-01

    The radiation characteristics of an antenna are fully determined by its aperture distribution. Measured Near Field data gives an impression but this is not good enough to detect small anomalies. For good antenna diagnostics, the field at the aperture plane is required. The Near Field Measurement Tec

  13. Antenna Miniaturization with MEMS Tunable Capacitors

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund

    2014-01-01

    and their characteristics are used in this investigation. This paper uses field simulations to highlight the trade-offs between the design of the tuner and the design of the antenna, especially the impact of the location of the tuner and the degree of miniaturization. Co-designing the tuner and the antenna is essential...

  14. Planar antenna system for direction finding

    Science.gov (United States)

    Mardale, Iulia-Cezara; Cocias, Gabriela; Dumitrascu, Ana; Tamas, Razvan; Berescu, Serban

    2015-02-01

    Applications of direction finding techniques include detection and localization of pulsed electromagnetic sources. This paper presents the design and analysis of a planar antenna system for direction finding. Our proposed system includes 4 hybrid couplers that generate 900 shifted signals, 2 crossover couplers also known as 0dB couplers, two 450 phase shifters, two 00 phase shifters and 4 patch antennas.

  15. Microstrip fractal-shaped antennas: a review

    OpenAIRE

    Anguera Pros, Jaume; Borja, C.; Puente Baliarda, Carles

    2007-01-01

    A review of electromagnetic features of microstrip antennas using fractal geometries is presented divided in four main areas: multi-frequency antennas, combination of multi- frequency with broadband techniques, high-directivity patches, and arrays with microstrip elements operating in localized modes Peer Reviewed

  16. 47 CFR 74.1237 - Antenna location.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna location. 74.1237 Section 74.1237... FM Broadcast Booster Stations § 74.1237 Antenna location. (a) An applicant for a new station to be... at which there is available a suitable signal from the primary station. The transmitting...

  17. Koch-Fractal Yagi-Uda Antenna

    DEFF Research Database (Denmark)

    Teisbæk, Henrik Bjørn; Jakobsen, Kaj Bjarne

    2009-01-01

    A Yagi-Uda antenna constructed of three Koch fractal elements is presented. Simulated and measured characteristics of the antenna shows a half-power beam-width of 64◦ achieved with dimensions below a third of a wavelength. Furthermore, the Koch dipole and its size miniaturization capabilities...

  18. A Case Study on Distributed Antenna Systems

    DEFF Research Database (Denmark)

    Sørensen, Troels Bundgaard

    2007-01-01

    Passive distributed antenna systems (DASs) consisting of distributed feeder lines or single point antennas are now often installed in large office buildings where they provide efficient coverage throughout the building. More sophisticated DASs with intelligent reuse and the ability to adapt...

  19. Antenna Design Exploiting the Duplex Isolation

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Pedersen, Gert Frølund

    2013-01-01

    A novel design addressing the antenna bandwidth issue for future communication standards on handsets is presented. It consists of a tunableantenna- pair for operation with a tunable front-end. The antennas are narrow-band and frequency-reconfigurable. This Letter focuses on the low communication...

  20. Antenna organization in green photosynthetic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Blankenship, R.E.

    1987-01-01

    This project is concerned with the structure and function of the unique antenna system found in the green photosynthetic bacteria. The antenna system in these organisms is contained within a vesicle known as a chlorosome, which is attached to the cytoplasmic side of the cell membrane. Additional antenna pigments and reaction centers are contained in integral membrane proteins. Energy absorbed by the bacteriochlorophyll c (BChl c) pigments in the chlorosome is transferred via a baseplate'' array of BChl a antenna pigments into the membrane and to the reaction center. A schematic model of chlorosome structure is shown. This project is aimed at increasing our understanding of the organization of the pigments in the chlorosome and how the antenna system functions.

  1. WIRELESS ENERGY TRANSFER USING MICROSTRIP ANTENNA

    Directory of Open Access Journals (Sweden)

    Leong Kah Meng

    2014-01-01

    Full Text Available This study presents a concept on wireless energy transmission using microstrip antenna pairs. Microstrip antenna is chosen in its implementation in wireless energy transfer application primarily due to its characteristics: Its ease of analysis, fabrication and their attractive radiation characteristics. The outcome of this research is the fabrication of two microstrip antennas with resonant frequency of 1.94 GHz and 2.5 GHz respectively. The performance and the power gain for each of microstrip antennas which act as the transmitter and receiver respectively were evaluated within certain distance. The limitations of the experiment as well as the possible solutions in increasing system efficiency are being discussed. Experiment shows that the microstrip antenna with a lower resonant frequency performs better in long distance wireless energy transmission.

  2. Enhancing molecule fluorescence with asymmetrical plasmonic antennas.

    Science.gov (United States)

    Lu, Guowei; Liu, Jie; Zhang, Tianyue; Shen, Hongming; Perriat, Pascal; Martini, Matteo; Tillement, Olivier; Gu, Ying; He, Yingbo; Wang, Yuwei; Gong, Qihuang

    2013-07-21

    We propose and justify by the finite-difference time-domain method an efficient strategy to enhance the spontaneous emission of a fluorophore with a multi-resonance plasmonic antenna. The custom-designed asymmetrical antenna consists of two plasmonic nanoparticles with different sizes and is able to couple efficiently to free space light through multiple localized surface plasmon resonances. This design simultaneously permits a large near-field excitation near the antenna as well as a high quantum efficiency, which results in an unusual and significant enhancement of the fluorescence of a single emitter. Such an asymmetrical antenna presents intrinsic advantages over single particle or dimer based antennas made using two identical nanostructures. This promising concept can be exploited in the large domain of light-matter interaction processes involving multiple frequencies.

  3. Textile UWB Antenna Bending and Wet Performances

    Directory of Open Access Journals (Sweden)

    Mai A. R. Osman

    2012-01-01

    Full Text Available The vision and ideas of wearable computing systems describe future electronic systems as an integral part of our everyday clothing that provides the wearer with such intelligent personal assistants. Recently, there has been growing interest in the antenna community to merge between wearable systems technology, ultrawideband (UWB technology and textile technology. This work aimed to make closer steps towards real wearability by investigating the possibilities of designing wearable UWB antenna where textile materials are used for the substrate as well as the conducting parts of the designed antenna. Two types of conducting materials have been used for conducting parts, while a nonconducting fabric has been used as antenna substrate material. A set of comparative results of the proposed design were presented and discussed. Moreover, effects on the return loss by means of measurements for each fabricated antenna prototype under bent and fully wet conditions were discussed in more details.

  4. Evolutionary Algorithm Geometry Optimization of Optical Antennas

    Directory of Open Access Journals (Sweden)

    Ramón Díaz de León-Zapata

    2016-01-01

    Full Text Available Printed circuit antennas have been used for the detection of electromagnetic radiation at a wide range of frequencies that go from radio frequencies (RF up to optical frequencies. The design of printed antennas at optical frequencies has been done by using design rules derived from the radio frequency domain which do not take into account the dispersion of material parameters at optical frequencies. This can make traditional RF antenna design not suitable for optical antenna design. This work presents the results of using a genetic algorithm (GA for obtaining an optimized geometry (unconventional geometries that may be used as optical regime antennas to capture electromagnetic waves. The radiation patterns and optical properties of the GA generated geometries were compared with the conventional dipole geometry. The characterizations were conducted via finite element method (FEM computational simulations.

  5. Structurally Integrated Antenna Concepts for HALE UAVs

    Science.gov (United States)

    Cravey, Robin L.; Vedeler, Erik; Goins, Larry; Young, W. Robert; Lawrence, Roland W.

    2006-01-01

    This technical memorandum describes work done in support of the Multifunctional Structures and Materials Team under the Vehicle Systems Program's ITAS (Integrated Tailored Aero Structures) Project during FY 2005. The Electromagnetics and Sensors Branch (ESB) developed three ultra lightweight antenna concepts compatible with HALE UAVs (High Altitude Long Endurance Unmanned Aerial Vehicles). ESB also developed antenna elements that minimize the interaction between elements and the vehicle to minimize the impact of wing flexure on the EM (electromagnetic) performance of the integrated array. In addition, computer models were developed to perform phase correction for antenna arrays whose elements are moving relative to each other due to wing deformations expected in HALE vehicle concepts. Development of lightweight, conformal or structurally integrated antenna elements and compensating for the impact of a lightweight, flexible structure on a large antenna array are important steps in the realization of HALE UAVs for microwave applications such as passive remote sensing and communications.

  6. Plasmonic Antennas Hybridized with Dielectric Waveguides

    CERN Document Server

    Arango, Felipe Bernal; Koenderink, A Femius

    2013-01-01

    For the purpose of using plasmonics in an integrated scheme where single emitters can be probed efficiently, we experimentally and theoretically study the scattering properties of single nano-rod gold antennas as well as antenna arrays placed on one-dimensional dielectric silicon nitride waveguides. Using real space and Fourier microscopy correlated with waveguide transmission measurements, we quantify the spectral properties, absolute strength and directivity of scattering. The scattering processes can be well understood in the framework of the physics of dipolar objects placed on a planar layered environment with a waveguiding layer. We use the single plasmonic structures on top of the waveguide as dipolar building blocks for new types of antennas where the waveguide enhances the coupling between antenna elements. We report on waveguide hybridized Yagi-Uda antennas which show directionality in out-coupling of guided modes as well as directionality for in-coupling into the waveguide of localized excitations ...

  7. Metamaterials and Metamaterial-Based Antenna Technology

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-ning

    2014-01-01

    The study of metamaterials is among the most important and attractive topics of the electromagnetic field theory and applications in the past 15 years. Much effort has been devoted to scientific research into the new physical phenomena with great progress. This paper presents the thoughts about the applications of metamaterials in innovative antenna designs from an engineering perspective. The new understanding of metamaterials offers us great possibility to translate the physical concepts of metamaterials in laborato-ries to innovative antenna designs in practical engineering applications. The technologies have been successfully developed, significantly improving key performances of antennas at microwave and millimeter-wave bands. The recently invented metamaterial-based antennas demonstrate not only wide operating bandwidth, high antenna efficiency, high gain, but also significantly reduced volume with simple mechanical structures.

  8. Advanced system characterizes antennas to 65 GHz

    Science.gov (United States)

    Francis, Michael H.; Kremer, Douglas P.; Repjar, Andrew G.

    1990-03-01

    The antenna measurement service offered by the National Institute of Standards and Technology provides radiation-pattern, on-axis gain, and polarization measurements to 65 GHz using planar near-field and extrapolation techniques. It is pointed out that measurements of millimeter-wave antennas are both difficult and costly to make and that such measurements require low-noise, high-power signal sources and exceptionally stable and repeatable connections. The process of the three-antenna extrapolation technique and subsequent measurements of dual-port circularly polarized antennas and swept-frequency gain measurements are analyzed, and antenna standards are noted. Insertion-loss measurements and attenuator calibration are discussed, and measurement uncertainties and far-field patterns are analyzed.

  9. A Microstripe Slotted Patch Antenna Using Amc

    Directory of Open Access Journals (Sweden)

    Manju Saini,

    2014-04-01

    Full Text Available Microstrip patch antenna offer an attractive solution to compact and ease-low-cost design of modern wireless communication system due to their many advantages as light weight and low volume, low profile, planer configuration which can be easily made conformal to low fabrication cost and capability of obtaining dual and triple frequency operations. A microstrip patch antenna with bandwidth enhancement by means of artificial magnetic conductor (AMC/electromagnetic band-gap structure (EBG is studied in this paper. The three different geometry shapes, the U, E and H are developed from rectangular patch. The antennas studied in this paper are simulated using sonnet software and results compared with the conventional rectangular patch antenna. The results obtained clearly shows that , bandwidth of conventional rectangular microstrip antenna can be enhanced has been studied

  10. STUDY ON A NOVEL ELLIPSOIDAL HELICAL ANTENNA

    Institute of Scientific and Technical Information of China (English)

    Xia Dongyu; Zhang Hou; Wang Chong; Zhang Qianyue

    2007-01-01

    A novel ellipsoidal helical antenna is proposed and studied in this letter.As a special instance,the hemispherical helical antennas are analyzed firstly,which indicates that the characteristics of a two-arm unit are better than that of a single-arm unit.Based on this,the ellipsoidal helical antenna,formed by changing the axial direction's dimension of the two-arm hemispherical helical antenna,is analyzed by the moment method with curved basic and testing function.The effects to VSWR (Voltage Standing Wave Ratio),gain,polarization and patterns by the axial direction's dimensions are investigated.The study results provide dependable gist to the choice of antenna format according to the practical requirements.

  11. Matching Parasitic Antenna for Single RF MIMO

    DEFF Research Database (Denmark)

    Han, Bo; Kalis, A; Nielsen, Rasmus Hjorth

    2012-01-01

    Single RF MIMO communication emerges a novel low cost communication method which does not consume as much power as the conventional MIMO. The implementation of such single RF MIMO system is done by mapping the weighting factors to the polarizations or the radiation patterns of the antennas....... In order to have such performance, an antenna with rich pattern modes is required by the system, thus the ESPAR antenna is investigated. The critical part on such antenna is parasitic element impedance matching. Unlike the conventional smith-chart matching method which assumes the minimal resistance...... is zero and with goal of 50 ohm or 75 ohm matching, matching on such parasitic antenna will adopt negative value as well. This paper presents a matching network with controllable impedance even to the range of negative values....

  12. A plasmonic dipole optical antenna coupled quantum dot infrared photodetector

    Science.gov (United States)

    Mojaverian, Neda; Gu, Guiru; Lu, Xuejun

    2015-12-01

    In this paper, we report a full-wavelength plasmonic dipole optical antenna coupled quantum dot infrared photodetector (QDIP). The plasmonic dipole optical antenna can effectively modify the EM wave distribution and convert free-space propagation infrared light to localized surface plasmonic resonance (SPR) within the nanometer (nm) gap region of the full-wavelength dipole antenna. The plasmonic dipole optical antenna coupled QDIP shows incident-angle-dependent photocurrent enhancement. The angular dependence follows the far-field pattern of a full-wavelength dipole antenna. The directivity of the plasmonic dipole optical antenna is measured to be 1.8 dB, which agrees well with the antenna simulation. To our best knowledge, this is the first report of the antenna far-field and directivity measurement. The agreement of the detection pattern and the directivity with antenna theory confirms functions of an optical antenna are similar to that of a RF antenna.

  13. Telecommunications Antennas for the Juno Mission to Jupiter

    Science.gov (United States)

    Vacchione, Joseph D.; Kruid, Ronald C.; Prata, Aluizio, Jr.; Amaro, Luis R.; Mittskus, Anthony P.

    2012-01-01

    The Juno Mission to Jupiter requires a full sphere of coverage throughout its cruise to and mission at Jupiter. This coverage is accommodated through the use of five (5) antennas; forward facing low gain, medium gain, and high gain antennas, and an aft facing low gain antenna along with an aft mounted low gain antenna with a torus shaped antenna pattern. Three of the antennas (the forward low and medium gain antennas) are classical designs that have been employed on several prior NASA missions. Two of the antennas employ new technology developed to meet the Juno mission requirements. The new technology developed for the low gain with torus shaped radiation pattern represents a significant evolution of the bicone antenna. The high gain antenna employs a specialized surface shaping designed to broaden the antenna's main beam at Ka-band to ease the requirements on the spacecraft's attitude control system.

  14. Antenna complexes protect Photosystem I from Photoinhibition

    Directory of Open Access Journals (Sweden)

    Hienerwadel Rainer

    2009-06-01

    Full Text Available Abstract Background Photosystems are composed of two moieties, a reaction center and a peripheral antenna system. In photosynthetic eukaryotes the latter system is composed of proteins belonging to Lhc family. An increasing set of evidences demonstrated how these polypeptides play a relevant physiological function in both light harvesting and photoprotection. Despite the sequence similarity between antenna proteins associated with the two Photosystems, present knowledge on their physiological role is mostly limited to complexes associated to Photosystem II. Results In this work we analyzed the physiological role of Photosystem I antenna system in Arabidopsis thaliana both in vivo and in vitro. Plants depleted in individual antenna polypeptides showed a reduced capacity for photoprotection and an increased production of reactive oxygen species upon high light exposure. In vitro experiments on isolated complexes confirmed that depletion of antenna proteins reduced the resistance of isolated Photosystem I particles to high light and that the antenna is effective in photoprotection only upon the interaction with the core complex. Conclusion We show that antenna proteins play a dual role in Arabidopsis thaliana Photosystem I photoprotection: first, a Photosystem I with an intact antenna system is more resistant to high light because of a reduced production of reactive oxygen species and, second, antenna chlorophyll-proteins are the first target of high light damages. When photoprotection mechanisms become insufficient, the antenna chlorophyll proteins act as fuses: LHCI chlorophylls are degraded while the reaction center photochemical activity is maintained. Differences with respect to photoprotection strategy in Photosystem II, where the reaction center is the first target of photoinhibition, are discussed.

  15. Antennas.

    Science.gov (United States)

    1982-03-03

    used to hold the central and cardan frames holding the gears and drive mechanisms which move the shaft which turns the small reflector. Then the "yoke...to be eliminated. In order to accommuodate the optical radiator, the construction of the cardan frame provides a free area near the center of the

  16. Optical Antenna Enhanced Spontaneous Emission in Semiconductors

    Science.gov (United States)

    Messer, Kevin James

    Optical antennas can be used to dramatically increase the rate that semiconductors spontaneously emit photons. While traditional LEDs are limited in bandwidth due to the "slow" rate of spontaneous emission, antenna-enhanced LEDs have the potential to be a fast, efficient, nanoscale light emitter. Traditionally, lasers have dominated LEDs as the emitter in optical interconnects due to a 200x speed advantage of stimulated emission over spontaneous emission. This paradigm may be reversed by coupling LEDs to optical antennas. In fact, antenna enhanced spontaneous emission can be faster than the fastest stimulated emission. Spontaneous emission originates from dipole fluctuations within the emitting material. The size of these fluctuations is much less than the wavelength of light emission, which leads to slow spontaneous emission. Coupling the material to an optical antenna corrects the size mismatch and improves the rate of radiation. An optical antenna circuit model is developed to predict the degree to which spontaneous emission can be enhanced. The circuit model presented in this dissertation shows that enhancement over 1000x is possible while still maintaining greater than 50% efficiency. The circuit model provides insight how to design optical antennas for coupling to dipole sources, for maximum enhancement, and for high efficiency. A method for incorporating the anomalous skin effect, often overlooked in metal optics, is provided. While FDTD/FEM simulations cannot include this effect due to its nonlocal nature, its impact can be examined through the use of the optical antenna circuit model. Analysis of the tradeoff between achieving large spontaneous emission enhancement and maintaining high efficiency leads to an ideal antenna feedgap size of 10nm. Experimental demonstration of spontaneous emission enhancement from InP coupled to an arch-dipole antenna is presented. Photoluminescence measurements show light emission from antenna-coupled InP over bare InP ridges

  17. Design of silicon-based fractal antennas

    KAUST Repository

    Ghaffar, Farhan A.

    2012-11-20

    This article presents Sierpinski carpet fractal antennas implemented in conventional low resistivity (Ï =10 Ω cm) as well as high resistivity (Ï =1500 Ω cm) silicon mediums. The fractal antenna is 36% smaller as compared with a typical patch antenna at 24 GHz and provides 13% bandwidth on high resistivity silicon, suitable for high data rate applications. For the first time, an on-chip fractal antenna array is demonstrated in this work which provides double the gain of a single fractal element as well as enhanced bandwidth. A custom test fixture is utilized to measure the radiation pattern and gain of these probe-fed antennas. In addition to gain and impedance characterization, measurements have also been made to study intrachip communication through these antennas. The comparison between the low resistivity and high resistivity antennas indicate that the former is not a suitable medium for array implementation and is only suitable for short range communication whereas the latter is appropriate for short and medium range wireless communication. The design is well-suited for compact, high data rate System-on-Chip (SoC) applications as well as for intrachip communication such as wireless global clock distribution in synchronous systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:180-186, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27245 Copyright © 2012 Wiley Periodicals, Inc.

  18. Scalable Notch Antenna System for Multiport Applications

    Directory of Open Access Journals (Sweden)

    Abdurrahim Toktas

    2016-01-01

    Full Text Available A novel and compact scalable antenna system is designed for multiport applications. The basic design is built on a square patch with an electrical size of 0.82λ0×0.82λ0 (at 2.4 GHz on a dielectric substrate. The design consists of four symmetrical and orthogonal triangular notches with circular feeding slots at the corners of the common patch. The 4-port antenna can be simply rearranged to 8-port and 12-port systems. The operating band of the system can be tuned by scaling (S the size of the system while fixing the thickness of the substrate. The antenna system with S: 1/1 in size of 103.5×103.5 mm2 operates at the frequency band of 2.3–3.0 GHz. By scaling the antenna with S: 1/2.3, a system of 45×45 mm2 is achieved, and thus the operating band is tuned to 4.7–6.1 GHz with the same scattering characteristic. A parametric study is also conducted to investigate the effects of changing the notch dimensions. The performance of the antenna is verified in terms of the antenna characteristics as well as diversity and multiplexing parameters. The antenna system can be tuned by scaling so that it is applicable to the multiport WLAN, WIMAX, and LTE devices with port upgradability.

  19. Piecewise-Planar Parabolic Reflectarray Antenna

    Science.gov (United States)

    Hodges, Richard; Zawadzki, Mark

    2009-01-01

    The figure shows a dual-beam, dualpolarization Ku-band antenna, the reflector of which comprises an assembly of small reflectarrays arranged in a piecewise- planar approximation of a parabolic reflector surface. The specific antenna design is intended to satisfy requirements for a wide-swath spaceborne radar altimeter, but the general principle of piecewise-planar reflectarray approximation of a parabolic reflector also offers advantages for other applications in which there are requirements for wideswath antennas that can be stowed compactly and that perform equally in both horizontal and vertical polarizations. The main advantages of using flat (e.g., reflectarray) antenna surfaces instead of paraboloidal or parabolic surfaces is that the flat ones can be fabricated at lower cost and can be stowed and deployed more easily. Heretofore, reflectarray antennas have typically been designed to reside on single planar surfaces and to emulate the focusing properties of, variously, paraboloidal (dish) or parabolic antennas. In the present case, one approximates the nominal parabolic shape by concatenating several flat pieces, while still exploiting the principles of the planar reflectarray for each piece. Prior to the conception of the present design, the use of a single large reflectarray was considered, but then abandoned when it was found that the directional and gain properties of the antenna would be noticeably different for the horizontal and vertical polarizations.

  20. SPS solid state antenna power combiner

    Science.gov (United States)

    Fitzsimmons, G. W.

    1980-01-01

    A concept for a solar power satellite antenna power combiner which utilizes solid state dc-rf converters is described. To avoid the power combining losses associated with circuit hybrids it is proposed that the power from multiple solid state amplifiers be combined by direct coupling of each amplifier's output to the radiating antenna structure. The selected power-combining antenna consists of a printed (metalized) microstrip circuit on a ceramic type dielectric substrate which is backed by a shallow lightweight aluminum cavity which sums the power of four microwave sources. The antenna behaves like two one-half wavelength slot-line antennas coupled together via their common cavity structure. A significant feature of the antenna configuration selected is that the radiated energy is summed to yield a single radiated output phase which represents the average insertion phase of the four power amplifiers. This energy may be sampled and, by comparison with the input signal, one can phase error correct to maintain the insertion phase of all solid state power combining modules at exactly the same value. This insures that the insertion phase of each SPS power combining antenna module is identical. An experiment verification program is described.

  1. Directive Antenna for Ultrawideband Medical Imaging Systems

    Directory of Open Access Journals (Sweden)

    Amin M. Abbosh

    2008-01-01

    Full Text Available A compact and directive ultrawideband antenna is presented in this paper. The antenna is in the form of an antipodal tapered slot with resistive layers to improve its directivity and to reduce its backward radiation. The antenna operates over the frequency band from 3.1 GHz to more than 10.6 GHz. It features a directive radiation with a peak gain which is between 4 dBi and 11 dBi in the specified band. The time domain performance of the antenna shows negligible distortion. This makes it suitable for the imaging systems which require a very short pulse for transmission/reception. The effect of the multilayer human body on the performance of the antenna is also studied. The breast model is used for this purpose. It is shown that the antenna has more than 90% fidelity factor when it works in free space, whereas the fidelity factor decreases as the signal propagates inside the human body. However, even inside the human body, the fidelity factor is still larger than 70% revealing the possibility of using the proposed antenna in biomedical imaging systems.

  2. Aerogel-Based Antennas for Aerospace and Terrestrial Applications

    Science.gov (United States)

    Meador, Mary Ann (Inventor); Miranda, Felix (Inventor); Van Keuls, Frederick (Inventor)

    2016-01-01

    Systems and methods for lightweight, customizable antenna with improved performance and mechanical properties are disclosed. In some aspects, aerogels can be used, for example, as a substrate for antenna fabrication. The reduced weight and expense, as well as the increased ability to adapt antenna designs, permits a systems to mitigate a variety of burdens associated with antennas while providing added benefits.

  3. Multiport antenna systems for space-time communications

    DEFF Research Database (Denmark)

    Tsakalaki, Elpiniki; Alrabadi, Osama; Pelosi, Mauro

    2013-01-01

    The paper presents the concept of multiport antenna systems where multiple active and passive ports are deployed. The passive ports, implemented via tunable reactance-assisted (parasitic) antennas, can alter the far-field and near-field properties of the antenna system expressed by the antenna ef...

  4. CPW to CPS transition for feeding UWB antennas

    DEFF Research Database (Denmark)

    Butrym, Alexander; Pivnenko, Sergey

    2004-01-01

    The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas in particular), bow-tie antennas, and other. Some numerical and experimental results...

  5. CPW to CPS transition for feeding UWB antennas

    DEFF Research Database (Denmark)

    Butrym, Alexander; Pivnenko, Sergey

    2006-01-01

    The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas, in particular), bow-tie antennas, and other. Some numerical and experimental results...

  6. 47 CFR 80.290 - Auxiliary receiving antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Auxiliary receiving antenna. 80.290 Section 80... antenna. An auxiliary receiving antenna must be provided when necessary to avoid unauthorized interruption or reduced efficiency of the required watch because the normal receiving antenna is not...

  7. 47 CFR 73.1213 - Antenna structure, marking and lighting.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna structure, marking and lighting. 73... SERVICES RADIO BROADCAST SERVICES Rules Applicable to All Broadcast Stations § 73.1213 Antenna structure... of Antenna Structures), requires certain antenna structures to be painted and/or lighted...

  8. 47 CFR 17.4 - Antenna structure registration.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  9. 47 CFR 24.55 - Antenna structures; air navigation safety.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Antenna structures; air navigation safety. 24... SERVICES PERSONAL COMMUNICATIONS SERVICES Technical Standards § 24.55 Antenna structures; air navigation safety. Licensees that own their antenna structures must not allow these antenna structures to become...

  10. 47 CFR 27.56 - Antenna structures; air navigation safety.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Antenna structures; air navigation safety. 27... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.56 Antenna structures; air navigation safety. A licensee that owns its antenna structure(s) must not allow such antenna structure(s)...

  11. Electromagnetic characterization of conformal antennas

    Science.gov (United States)

    Volakis, John L.; Kempel, Leo C.; Alexanian, Angelos; Jin, J. M.; Yu, C. L.; Woo, Alex C.

    1992-01-01

    The ultimate objective of this project is to develop a new technique which permits an accurate simulation of microstrip patch antennas or arrays with various feed, superstrate and/or substrate configurations residing in a recessed cavity whose aperture is planar, cylindrical or otherwise conformed to the substructure. The technique combines the finite element and boundary integral methods to formulate a system suitable for solution via the conjugate gradient method in conjunction with the fast Fourier transform. The final code is intended to compute both scattering and radiation patterns of the structure with an affordable memory demand. With upgraded capabilities, the four included papers examined the radar cross section (RCS), input impedance, gain, and resonant frequency of several rectangular configurations using different loading and substrate/superstrate configurations.

  12. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    State-of-the-art microwave systems always require higher performance and lower cost microwave components. Constantly growing demands and performance requirements of industrial and scientific applications often make employing traditionally designed components impractical. For that reason, the design...... and development process remains a great challenge today. This problem motivated intensive research efforts in microwave design and technology, which is responsible for a great number of recently appeared alternative approaches to analysis and design of microwave components and antennas. This book highlights...... techniques. Modelling and computations in electromagnetics is a quite fast-growing research area. The recent interest in this field is caused by the increased demand for designing complex microwave components, modeling electromagnetic materials, and rapid increase in computational power for calculation...

  13. Development of Novel Integrated Antennas for CubeSats

    Science.gov (United States)

    Jackson, David; Fink, Patrick W.; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Development of Novel Integrated Antennas for CubeSats project is directed at the development of novel antennas for CubeSats to replace the bulky and obtrusive antennas (e.g., whip antennas) that are typically used. The integrated antennas will not require mechanical deployment and thus will allow future CubeSats to avoid potential mechanical problems and therefore improve mission reliability. Furthermore, the integrated antennas will have improved functionality and performance, such as circular polarization for improved link performance, compared with the conventional antennas currently used on CubeSats.

  14. Low-Q Electrically Small Spherical Magnetic Dipole Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2010-01-01

    Three novel electrically small antenna configurations radiating a TE10 spherical mode corresponding to a magnetic dipole are presented and investigated: multiarm spherical helix (MSH) antenna, spherical split ring resonator (S-SRR) antenna, and spherical split ring (SSR) antenna. All three antennas...... are self-resonant, with the input resistance tuned to 50 ohms by an excitation curved dipole/monopole. A prototype of the SSR antenna has been fabricated and measured, yielding results that are consistent with the numerical simulations. Radiation quality factors (Q) of these electrically small antennas (in...

  15. Compact antennas for wireless communications and terminals theory and design

    CERN Document Server

    Laheurte, Jean-Marc

    2012-01-01

    Compact Antennas for Wireless Communications and Terminals deals with compact microwave antennas and, more specifically, with the planar version of these antennas. Planar antennas are the most appropriate type of antenna in modern communication systems and more generally in all applications requiring miniaturization, integration and conformation such as in mobile phone handsets.The book is suitable for students, engineers and scientists eager to understand the principles of planar and small antennas, their design and fabrication issues, and modern aspects such as UWB antennas, recon

  16. Location Refinement and Power Coverage Analysis Based on Distributed Antenna

    Institute of Scientific and Technical Information of China (English)

    赵晓楠; 侯春萍; 汪清; 陈华; 浦亮洲

    2016-01-01

    To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel im-pulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin.

  17. A Review of the Four Dimension Antenna Arrays

    Institute of Scientific and Technical Information of China (English)

    YANG Shi-wen; NIE Zai-ping

    2006-01-01

    The four dimensional (4D) antenna arrays introduce a fourth dimension, time, into conventional antenna arrays to offer greater flexibility in the design of high performance antenna arrays. This paper presents the tutorial on the study of 4D antenna arrays and the review of the recent research findings on 4D antenna arrays. Issues considered include the theory of 4D antenna arrays, different time modulation schemes, numerical simulation results, and some experimental results on their applications to low sidelobe designs. Throughout the discussion, some challenging issues on the study of 4D antenna arrays are highlighted.

  18. A Fast Adaptive Receive Antenna Selection Method in MIMO System

    Directory of Open Access Journals (Sweden)

    Chaowei Wang

    2013-01-01

    Full Text Available Antenna selection has been regarded as an effective method to acquire the diversity benefits of multiple antennas while potentially reduce hardware costs. This paper focuses on receive antenna selection. According to the proportion between the numbers of total receive antennas and selected antennas and the influence of each antenna on system capacity, we propose a fast adaptive antenna selection algorithm for wireless multiple-input multiple-output (MIMO systems. Mathematical analysis and numerical results show that our algorithm significantly reduces the computational complexity and memory requirement and achieves considerable system capacity gain compared with the optimal selection technique in the same time.

  19. Innovation in wearable and flexible antennas

    CERN Document Server

    Khaleel, Haider

    2014-01-01

    This book deals with the design, numerical simulation, state of the art fabrication processes and methods, qualitative and quantitative tests, and measurement techniques of wearable and flexible antennas of different topologies, such as: Planar Inverted F, Printed Monopoles, Micropoles and Microstrips. Novel trends, materials, and fabrication and measurement techniques used in this vital field of antenna systems are also discussed.To the best of the editor's knowledge, at the time of publication, there are no published books targeting the vital topic of flexible antennas specifically and/or se

  20. Implanted Antennas in Medical Wireless Communications

    CERN Document Server

    Rahmat-Samii, Yahya; Balanis, Constantine

    2006-01-01

    Implanted Antennas in Medical Wireless Communications summarizes the results of recent research activities on the subject of implanted antennas for medical wireless communication systems. It is anticipated that in the near future sophisticated medical devices will be implanted inside the human body for medical telemetry and telemedicine. To establish effective and efficient wireless links with these devices, it is pivotal to give special attention to antenna designs that are low profile, small, safe, and cost effective. In this book, authors Yahya Rahmat-Samii and Jaehoon Kim demonstrate how a

  1. Planar Tri-Band Antenna Design

    Directory of Open Access Journals (Sweden)

    M. Pokorny

    2008-04-01

    Full Text Available The paper briefly uncovers techniques used for a design of compact planar antennas in order to achieve the wideband and the multi-band capability. The main topic is aimed to the multi-objective optimization using genetic algorithms. A quarter-wavelength planar inverted-F antenna (PIFA using a slot and shorted parasitic patches is chosen to cover GSM900, GSM1800 and ISM2400 bands. A global multi-objective optimization uses a binary genetic algorithm with a composite objective function to tune this antenna. The impedance match and the direction of maximum gain are desired parameters to improve.

  2. FDTD simulation tools for UWB antenna analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2004-12-01

    This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

  3. Smooth Tracking Trajectory Generation of Large Antenna

    Directory of Open Access Journals (Sweden)

    Upnere S.

    2016-02-01

    Full Text Available The current paper presents an engineering approach for studies of the control algorithm designed for a mechanically robust large antenna. Feed-forward control methods with the 3rd-order polynomial tracking algorithm are supplemented to the original feed-back PID control system. Dynamical model of the existing servo system of 32m radio telescope has been developed to widen a case analysis of observation sessions and efficiency of the control algorithms due to limited access to an antenna. Algorithms along with the results from the system implemented on a real antenna as well as model results are presented.

  4. Land vehicle antennas for satellite mobile communications

    Science.gov (United States)

    Haddad, H. A.; Pieper, B. V.; Mckenna, D. B.

    1985-01-01

    The RF performance, size, pointing system, and cost were investigated concepts are: for a mechanically steered 1 x 4 tilted microstrip array, a mechanically steered fixed-beam conformal array, and an electronically steered conformal phased array. Emphasis is on the RF performance of the tilted 1 x 4 antenna array and methods for pointing the various antennas studied to a geosynchronous satellite. An updated version of satellite isolations in a two-satellite system is presented. Cost estimates for the antennas in quantities of 10,000 and 100,000 unites are summarized.

  5. A new patch antenna with metamaterial cover

    Institute of Scientific and Technical Information of China (English)

    HU Jun; YAN Chun-sheng; LIN Qing-chun

    2006-01-01

    A metamaterial was introduced into the cover of a patch antenna and its band structure was analyzed. The metamaterial cover with correct selection of the working frequency increases by 9.14 dB the patch antenna's directivity. The mechanism of metamaterial cover is completely different from that of a photonic bandgap cover. The mechanism of the metamaterial cover,the number of the cover's layers, and the distance between the layers, were analyzed in detail. The results showed that the metamaterial cover, which works like a lens, could effectively improve the patch antenna's directivity. The physical reasons for the improvement are also given.

  6. A novel space-diversity antenna system

    Science.gov (United States)

    Cocias, Gabriela; Mardale, Iulia-Cezara; Dumitrascu, Ana; Tamas, Razvan D.; Berescu, Serban

    2015-02-01

    This paper presents the structure and analysis of a space diversity antenna system designed for indoor applications. The proposed antenna system consists of two meander monopole antennas with a 0.7 mm wide connection and a 85x35 mm ground plane, conceived and optimized to reduce the mutual coupling between the two radiating elements. We used a simplified deterministic model, based on geometric optics, consisting of two reflecting perpendicular walls, in order to assess the performance of our radiating system in a multipath environment.

  7. Slot Antenna for Wireless Temperature Measurement Systems

    DEFF Research Database (Denmark)

    Acar, Öncel; Jakobsen, Kaj Bjarne

    2016-01-01

    This paper presents a novel clover-slot antenna for a surface-acoustic-wave sensor based wireless temperature measurement system. The slot is described by a parametric locus curve that has the shape of a clover. The antenna is operated at high temperatures, in rough environments, and has a 43......% fractional bandwidth at the 2.4 GHz ISM-band. The slot antenna has been optimized for excitation by a passive chip soldered onto it. Measurement results are compared with simulation results and show good agreements....

  8. Graphene array antenna for 5G applications

    Science.gov (United States)

    Sa'don, Siti Nor Hafizah; Kamarudin, Muhammad Ramlee; Ahmad, Fauzan; Jusoh, Muzammil; Majid, Huda A.

    2017-02-01

    Fifth generation (5G) needs to provide better coverage than the previous generation. However, high frequency and millimeter wave experience penetration loss, propagation loss and even more loss in energy for long distance. Hence, a graphene array antenna is proposed for high gain to cover a long distance communications since array antenna enables in providing more directive beams. The investigation is conducted on three types of substrates with gain achieved is more than 7 dBi. The gain obtained is good since it is comparable with other studies. In addition, these antennas consume small numbers of elements to achieve high gain.

  9. Antenna development for high field plasma imaging.

    Science.gov (United States)

    Kong, X; Domier, C W; Luhmann, N C

    2010-10-01

    Electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry (MIR) are two microwave nonperturbing plasma visualization techniques that employ millimeter-wave imaging arrays with lens-coupled planar antennas, yielding time-resolved images of temperature (via ECEI) and electron density (via MIR) fluctuations within high temperature magnetic fusion plasmas. A series of new planar antennas have been developed that extend this technology to frequencies as high as 220 GHz for use on high field plasma devices with toroidal fields in excess of 3 T. Antenna designs are presented together with theoretical calculations, simulations, and experimental measurements.

  10. Vertically Polarized Omnidirectional Printed Slot Loop Antenna

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

    2015-01-01

    A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

  11. YAGI UDA SHAPED DUAL RECONFIGURABLE ANTENNA

    Directory of Open Access Journals (Sweden)

    Y Srinivas

    2016-06-01

    Full Text Available In this paper, YagiUda shaped rectangular microstrip patch antenna fed by inset feed is designed to operate for frequency and polarization reconfigurability is presented. It consists of a square patch with four corners truncated and three parasitic patches placed on top. It operates as a frequency and polarization, reconfigurable antenna. Switches are placed in the gaps of truncated corners to obtain switching between Linear, Circular polarizations. The proposed antenna also switches between two frequencies by controlling current path between main and parasitic patches through switches. Its performance evaluation is carried out with the help of simulation and physical verification and the results are presented.

  12. Field-aligned-impedance-transforming ICRF antenna in the LHD

    Energy Technology Data Exchange (ETDEWEB)

    Saito, K., E-mail: saito@nifs.ac.jp; Seki, T.; Kasahara, H.; Seki, R.; Kamio, S.; Nomura, G.; Mutoh, T.

    2015-10-15

    Newly developed ion cyclotron range of frequencies (ICRF) antennas were fabricated and installed in the Large Helical Device (LHD). The antennas, called field-aligned-impedance-transforming (FAIT) antennas, were designed based on former handshake form (HAS) antennas for high power and steady-state operation. The FAIT antennas demonstrated higher loading resistance and lower temperature on ceramic feed-through than HAS antennas. Antenna impedance and injected power were measured precisely using a directional coupler installed between the impedance matching device and antenna. It was shown that an injection power of 1.8 MW or a power density of 15 MW/m{sup 2} would be possible for short-pulse discharges. The mutual coupling between two FAIT antennas is small enough, since any current phase is possible without adjusting the impedance matching device. Although the FAIT antennas are aligned in a poloidal direction, a high heating efficiency of 85% was achieved with the proper minority concentration ratio.

  13. Technique for Radiometer and Antenna Array Calibration with Two Antenna Noise Diodes

    Science.gov (United States)

    Srinivasan, Karthik; Limaye, Ashutosh; Laymon, Charles; Meyer, Paul

    2011-01-01

    This paper presents a new technique to calibrate a microwave radiometer and phased array antenna system. This calibration technique uses a radiated noise source in addition to an injected noise sources for calibration. The plane of reference for this calibration technique is the face of the antenna and therefore can effectively calibration the gain fluctuations in the active phased array antennas. This paper gives the mathematical formulation for the technique and discusses the improvements brought by the method over the existing calibration techniques.

  14. High-Q Antennas with built-in coils

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Svendsen, Simon; Pedersen, Gert Frølund

    2014-01-01

    Efficiency and isolation, at low frequencies (700 MHz), are two of the most important metrics for successful multicommunication implementation. This paper presents an antenna concept, that exhibits a very high isolation between high-Q Tx and Rx antennas at 700 MHz. Furthermore, it is shown how...... coils can be integrating into the antenna structure for obtaining better efficiency. It is shown that by integrated coils into the antenna structure, the efficiency can be improved by 2dB for each antenna....

  15. 6.1 Research Areas in the Antenna Group

    Science.gov (United States)

    2014-07-01

    Master’s thesis in 2014. • Dr Steven Weiss is the Team Leader for the Antenna Team. • Eric Adler is the Branch Chief of the Antennas and RF...spherical dipoles, wideband electromagnetic bandgap (EBG) surfaces, ultra-wideband, and tapered slot antennas. The realization of the antenna designs...of a typical 180 ohms. A dipole antenna has been enhanced to radiate at least 2 dB greater than a typical dipole by forming a narrow azimuth beam

  16. Radiation Analysis and Characteristics of Conformal Reflectarray Antennas

    Directory of Open Access Journals (Sweden)

    Payam Nayeri

    2012-01-01

    Full Text Available This paper investigates the feasibility of designing reflectarray antennas on conformal surfaces. A generalized analysis approach is presented that can be applied to compute the radiation performance of conformal reflectarray antennas. Using this approach, radiation characteristics of conformal reflectarray antennas on singly curved platforms are studied and the performances of these designs are compared with planar designs. It is demonstrated that a conformal reflectarray antenna can be a suitable choice for applications requiring high-gain antennas on curved platforms.

  17. Planar Millimeter-Wave Antennas: A Comparative Study

    Directory of Open Access Journals (Sweden)

    K. Pitra

    2011-04-01

    Full Text Available The paper describes the design and the experimental verification of three types of wideband antennas. Attention is turned to the bow-tie antenna, the Vivaldi antenna and the spiral antenna designed for the operation at millimeter waves. Bandwidth, input impedance, gain, and directivity pattern are the investigated parameters. Antennas are compared considering computer simulations in CST Microwave Studio and measured data.

  18. Electrically small, complementary electric-field-coupled resonator antennas

    Science.gov (United States)

    Odabasi, H.; Teixeira, F. L.; Guney, D. O.

    2013-02-01

    We study the radiation properties of electrically small resonant antennas (ka CELC) resonators and a monopole antenna. We use such parasitic ELC and CELC "metaresonators" to design various electrically small antennas. In particular, monopole-excited and bent-monopole-excited CELC resonator antennas are proposed that provide very low profiles on the order of λ0/20. We compare the performance of the proposed ELC and CELC antennas against more conventional designs based upon split-ring resonators.

  19. Dual-Frequency Operation of Bow-Tie Microstrip Antenna

    Institute of Scientific and Technical Information of China (English)

    钟顺时; 张需溥

    2005-01-01

    Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is shown that the dual-frequency ratio can be controlled easily by choosing the parameters of the antenna. This design gives compact antenna size and simple antenna structure. Experimental results are presented, verifying the validity of the design.

  20. Fluorescence enhancement factors on optical antennas: enlarging the experimental values without changing the antenna design

    CERN Document Server

    Wenger, Jerome

    2011-01-01

    Plasmonic antennas offer promising opportunities to control the emission of quantum objects. As a consequence, the fluorescence enhancement factor is widely used as a figure of merit for a practical antenna realization. However, the fluorescence enhancement factor is not an intrinsic property of the antenna. It critically depends on several parameters, some of which are often disregarded. In this contribution, I explore the influence of the setup collection efficiency, emitter's quantum yield and excitation intensity. Improperly setting these parameters may significantly alter the enhancement values, leading to potential misinterpretations. The discussion is illustrated by an antenna example of a nanoaperture surrounded by plasmonic corrugations.

  1. A Liquid Metal Conical Helical Antenna for Circular Polarization-Reconfigurable Antenna

    Directory of Open Access Journals (Sweden)

    Yun Zhou

    2016-01-01

    Full Text Available A novel polarization-reconfigurable conical helical antenna based on the liquid metal is presented. The antenna is implemented by using truncated structure, variable pitch angle, a matching stub, and a mechanical autorotation device. The experimental results show that a good agreement between simulations and measurements is obtained. The gain of the antenna achieves higher than 8 dBi in the work band (1525–1660.5 MHz, and the 3 dB axial ratio (AR bandwidth reaches 410 MHz. The polarization mode of the antenna can be switched between right-hand and left-hand circular polarization.

  2. Fluorescence Enhancement Factors on Optical Antennas: Enlarging the Experimental Values without Changing the Antenna Design

    Directory of Open Access Journals (Sweden)

    Jérôme Wenger

    2012-01-01

    Full Text Available Plasmonic antennas offer promising opportunities to control the emission of quantum objects. As a consequence, the fluorescence enhancement factor is widely used as a figure of merit for a practical antenna realization. However, the fluorescence enhancement factor is not an intrinsic property of the antenna. It critically depends on several parameters, some of which are often disregarded. In this contribution, I explore the influence of the setup collection efficiency, emitter's quantum yield, and excitation intensity. Improperly setting these parameters may significantly alter the enhancement values, leading to potential misinterpretations. The discussion is illustrated by an antenna example of a nanoaperture surrounded by plasmonic corrugations.

  3. An Overview of Antenna R&D Efforts in Support of NASA's Space Exploration Vision

    Science.gov (United States)

    Manning, Robert M.

    2007-01-01

    This presentation reviews the research and development work being conducted at Glenn Research Center in the area of antennas for space exploration. In particular, after reviewing the related goals of the agency, antenna technology development at GRC is discussed. The antennas to be presented are large aperture inflatable antennas, phased array antennas, a 256 element Ka-band antenna, a ferroelectric reflectarray antenna, multibeam antennas, and several small antennas.

  4. Radio Astronomy Antennas by the Thousands

    Science.gov (United States)

    Schultz, Roger

    2004-06-01

    Large number of microwave antennas of size and surface accuracy appropriate for the Square Kilometre Array (SKA) have not been manufactured previously. To minimize total cost, the design needs to be much more carefully considered and optimized than would be affordable for a small number of antennas. The required surface area requires new methods of manufacture and production-line type assembly to be considered. A blend of past antenna construction technology, creativity, and new technology is needed to provide the best possible telescope for the proposed SKA science goals. The following key concepts will be discussed with respect to reflector antennas and many supporting photographs, figures and drawings will be included. Surface and supporting structure comparison of panels with a one-piece shell as produced by hydroforming.

  5. NRAO RF Anechoic Chamber & Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

  6. Microfabricated Millimeter-Wave Antenna Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the need for an antenna technology platform that meets the requirements of high-performance materials, exacting dimensional tolerances, and...

  7. Signal separator for dual-frequency antenna

    Science.gov (United States)

    Hartop, R. W.

    1979-01-01

    Replacement for dichroic plate reduces noise. Besides being easier to install, flange is less expensive to fabricate. Most important, the flange reduces antenna contribution to system noise; whereas, dichroic plate increases noise temperature by 2 or 3 degrees.

  8. Low Cost Phased Array Antenna System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JEM Engineering proved the technical feasibility of the FlexScan array?a very low-cost, highly-efficient, wideband phased array antenna?in Phase I, and stands ready...

  9. Wideband P-Shaped Dielectric Resonator Antenna

    Directory of Open Access Journals (Sweden)

    M.Khalily

    2013-04-01

    Full Text Available A novel P-shaped dielectric resonator antenna (DRA is presented and investigated for wideband wireless application. By using P-shaped resonator, a wideband impedance bandwidth of 80% from 3.5 to 8.2 GHz is achieved. The antenna covers all of wireless systems like C-band, 5.2, 5.5 and 5.8 GHz-WLAN and WiMax. The proposed antenna has a low profile and the thickness of the resonator is only 5.12 mm, which is 0.06-0.14 free space wavelength. A parametric study is presented. The proposed DRA is built and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained.

  10. Metamaterial Multiband Antenna for Wireless Application

    Directory of Open Access Journals (Sweden)

    Nader AZIZI

    2014-01-01

    Full Text Available In this work a Multi-band antenna along with the innovative metamaterial structure is proposed which consists of a circular geometry incorporated with c shaped structure. This work is mainly focused on increasing the potential parameters of planar antennas and analyzing the multi band operation of proposed antenna. The impedance bandwidth of proposed antenna are covered and utilized frequency range of (2.6~3.1 GHz, (3.5~4.4 GHz and (4.7~6.2 GHz. For verifying that the proposed metamaterial structure possesses Negative values of Permeability and Permittivity within the operating frequency ranges, Nicolson-Ross-Weir method (NRW has been employed. For simulation purpose HFSS Software has been used.

  11. Slot Coupled Patch Array Antenna Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is an antenna array whose beam is controlled digitally. The Phase 1 effort will assess the method needed to achieve the gain, bandwidth, and...

  12. Phase shifter for antenna beam steering

    Science.gov (United States)

    Jindal, Ravi; Razban, Tchanguiz

    2016-03-01

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  13. Advanced Antenna for Digital Beamforming SAR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a wideband (500 MHz) L-band phased-array antenna for airborne Synthetic Aperture Radar (SAR) applications based on a novel approach that will make possible...

  14. A note on antennas: Definitions and methods

    DEFF Research Database (Denmark)

    Bach, Henning

    1987-01-01

    Definitions of scattered and diffracted fields, originally given by R. F. Millar, are reviewed and supplemented. The definitions are used to discuss relations between results obtained by commonly used pattern prediction methods for reflector antennas....

  15. Antenna standards and laboratories in Europe

    DEFF Research Database (Denmark)

    Lemanczyk, Jerzy

    1995-01-01

    This paper sets out to present an overview of antenna standards and laboratories within Europe. In this context, Europe is limited geographically to the member nations of the European Union (EU), formerly the European Community, and the European Space Agency (ESA). In addition to these two...... Institute and EAL, the European Accreditation of Laboratories, which deals with the practical aspects of laboratory accreditation and international cooperation. ESA, through the Electromagnetics Division of ESTEC, has been active in not only defining the need for European sourced antenna gain standards......, but has embarked on a project of antenna range validation as well as defining standardization of validation procedures to better monitor and improve the performance of antenna test laboratories working on ESA projects...

  16. PBG based terahertz antenna for aerospace applications

    CERN Document Server

    Choudhury, Balamati; Jha, Rakesh Mohan

    2016-01-01

    This book focuses on high-gain antennas in the terahertz spectrum and their optimization. The terahertz spectrum is an unallocated EM spectrum, which is being explored for a number of applications, especially to meet increasing demands of high data rates for wireless space communications. Space communication systems using the terahertz spectrum can resolve the problems of limited bandwidth of present wireless communications without radio-frequency interference. This book describes design of such high-gain antennas and their performance enhancement using photonic band gap (PBG) substrates. Further, optimization of antenna models using evolutionary algorithm based computational engine has been included. The optimized high-performance compact antenna may be used for various wireless applications, such as inter-orbital communications and on-vehicle satellite communications.

  17. Integrated 222-GHz corner-reflector antennas

    Science.gov (United States)

    Gearhart, Steven S.; Ling, Curtis C.; Rebeiz, Gabriel M.

    1991-01-01

    A high-gain monolithic millimeter-wave antenna has been designed, fabricated, and tested at 222 GHz. The structure consists of a traveling-wave antenna integrated on a 1.2-micron dielectric membrane and suspended in a longitudinal cavity etched in a silicon wafer. A new traveling-wave antenna design yields a wideband input impedance and a low cross-polarization component in the E- and quasi-H-plane patterns. A directivity of 17.7 dB and a main-beam efficiency of 88.5 percent are calculated from the 222-GHz pattern measurements. The integrated corner-reflector antenna is well suited for millimeter- and submillimeter-wave imaging applications in large f-number systems.

  18. A Modal Description of Multiport Antennas

    Directory of Open Access Journals (Sweden)

    Jonathan J. Lynch

    2011-01-01

    Full Text Available This paper presents a modal description of multiport antennas that leads directly to a rigorous network representation and simple quadratic expressions for gain, efficiency, and effective area. The analysis shows that the transmitting and receiving properties of an element antenna array are exactly described by a 2×2 element scattering matrix together with a set of orthonormal mode functions and accounts for effects such as mutual coupling, scattering, reflection, and losses. The approach is quite general, only requiring that the antenna be finite and reciprocal. The scattering network description simplifies accounting of power flow while retaining a close connection to the physical antenna characteristics. The orthonormal mode functions provide a complete basis for radiated and received fields, facilitating beamforming. The theory provides rigorous definitions of input-output signals and links them to the underlying electromagnetics in a straightforward manner.

  19. Resonance spectra of diabolo optical antenna arrays

    Directory of Open Access Journals (Sweden)

    Hong Guo

    2015-10-01

    Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  20. High Tc superconducting small loop antenna

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Mehler, M.J.; Maclean, T.S.M.; Lancaster, M.J.; Gough, C.E. (Univ. of Birmingham (UK)); Alford, N. (I.C.I. Advanced Materials Div., Runcorn (UK))

    1989-12-01

    The improvement in the radiation efficiency of an electrically small loop antenna is analysed when it is fabricated from a superconductor, and experimental results for a liquid nitrogen cooled, ceramic superconducting loop at 450MHz are presented. (orig.).

  1. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  2. Microfabricated G-Band Antenna Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the need for an antenna technology platform that meets the requirements of high-performance materials, exacting dimensional tolerances, and...

  3. Antenna Pattern Impact on MIMO OTA Testing

    DEFF Research Database (Denmark)

    Fan, Wei; Nielsen, Jesper Ødum; Franek, Ondrej

    2013-01-01

    This paper investigates the impact of the DUT antenna pattern on the test area performance for multi-probe based MIMO OTA setup in terms of received voltage and spatial correlation. The plane wave synthesis (PWS) technique has been proposed for vertical polarization in the literature, where...... the goal is to approximate plane waves with arbitrary directions. The received voltage at the antenna terminal depends on the antenna radiation pattern and the impinging plane waves. A novel closed form technique to reproduce the received voltage with arbitrary incoming plane waves based on trigonometric...... interpolation is presented. The proposed technique provides a closed form solution for the PWS when the probe ring radius is infinite. The proposed technique shows that the impact of the antenna pattern on the induced received voltage accuracy is ruled by Nyquist sampling theory. Furthermore, the impact...

  4. Multiband Photonic Phased-Array Antenna

    Science.gov (United States)

    Tang, Suning

    2015-01-01

    A multiband phased-array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. Crystal Research, Inc., has developed a multiband photonic antenna that is based on a high-speed, optical, true-time-delay beamformer. It is capable of simultaneously steering multiple independent radio frequency (RF) beams in less than 1,000 nanoseconds. This high steering speed is 3 orders of magnitude faster than any existing optical beamformer. Unlike other approaches, this technology uses a single controlling device per operation band, eliminating the need for massive optical switches, laser diodes, and fiber Bragg gratings. More importantly, only one beamformer is needed for all antenna elements.

  5. Stockbridge Antenna Measurement and Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Stockbridge Antenna Measurement Facility is located 23 miles southwest of AFRL¹s Rome Research Site. This unique measurement facility is designed to evaluate the...

  6. MEMS-Enabled Smart Reconfigurable Antennas Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A prototype wearable smart reconfigurable antenna for the Suit will be built to be used during NASA's EVA operations on lunar surface. The design is based on the...

  7. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves

    2012-01-01

    Full Text Available This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna reconfiguration technique based on PIN diodes is applied. This procedure allows the change of the active form of the antenna leading to a shift in the resonant frequency. The prototype measurements show good agreement with the simulation results.

  8. MULTI SEGMENT CIRCULAR FRACTAL REFLECT ARRAY ANTENNA

    Directory of Open Access Journals (Sweden)

    Bahareh Baghani BAJGIRAN

    2014-01-01

    Full Text Available in this paper with using novel fractal structure which is composed of multi segment circular fractal. A unit cell and then reflectarray antenna have been designed. The unit cell of reflect array has been designed in 4.4 GHz with 24*24*1 mm3 dimension. The reflectarray is consist of 400 (20* 20 elements that even element is placed in the locus has been calculated. Maximum gain of antenna is 12.9 dBi.

  9. 3D Printing Electrically Small Spherical Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2013-01-01

    3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....

  10. Antenna Splitting Functions for Massive Particles

    Energy Technology Data Exchange (ETDEWEB)

    Larkoski, Andrew J.; Peskin, Michael E.; /SLAC

    2011-06-22

    An antenna shower is a parton shower in which the basic move is a color-coherent 2 {yields} 3 parton splitting process. In this paper, we give compact forms for the spin-dependent antenna splitting functions involving massive partons of spin 0 and spin 1/2. We hope that this formalism we have presented will be useful in describing the QCD dynamics of the top quark and other heavy particles at LHC.

  11. A spiral antenna sandwiched by dielectric layers

    OpenAIRE

    Nakano, Hisamatsu; Ikeda, Masakazu; Hitosugi, Kazuo; Yamauchi, Junji

    2004-01-01

    An infinitesimally thin spiral antenna, sandwiched by bottom and top dielectric layers having the same relative permittivity, is analyzed under the condition that the dielectric layers are of finite extent and the antenna is backed by an infinite conducting plane. As the thickness of the top dielectric layer increases, the input impedance and axial ratio (AR) vary in an oscillatory fashion, with a period slightly larger than one-half of the guided wavelength of a wave propagating in an unboun...

  12. Steerable optical antennas by selective heating.

    Science.gov (United States)

    Cuadrado, Alexander; González, Francisco Javier; Alda, Javier

    2014-04-01

    Directional steerability can be obtained for an array of optical antennas through selective heating of the individual elements. Heating changes electrical conductivity of the heated element, which affects the phase of the generated currents. The variation in temperature can be obtained by modifying the biasing point of the individual elements of the array, which would allow fast reconfiguration. The numerical evaluation of the performance of an array of a reduced number of antennas (2 and 3) shows the feasibility of this approach.

  13. Tunable Patch Antennas Using Microelectromechanical Systems

    Science.gov (United States)

    2011-05-11

    wavelength of the desired resonant frequency [1]. (25) To aid in the design process a MATLAB script was written to solve for patch antenna...10–12, the widths of 50 Ω and 112 Ω microstrip lines were calculated using a MATLAB script included as an appendix to this report. The calculated...2009, pp. 50–55. [11] W.L. Stutzman, G.A. Thiele , Antenna Theory and Design, Second Edition, John Wiley & Sons, Inc. (Hoboken, New Jersey), 1998, pp

  14. OPTIMAL DESIGN OF SMART ANTENNA ARRAY

    Institute of Scientific and Technical Information of China (English)

    Gao Feng; Liu Qizhong; Shan Runhong; Zhang Hou

    2004-01-01

    This letter investigates an efficient design procedure integrating the Genetic Algorithm (GA) with the Finite Difference Time Domain (FDTD) for the fast optimal design of Smart Antenna Arrays (SAA). The FDTD is used to analyze SAA with mutual coupling. Then,on the basis of the Maximal Signal to Noise Ratio (MSNR) criteria, the GA is applied to the optimization of weighting elements and structure of SAA. Finally, the effectiveness of the analysis is evaluated by experimental antenna arrays.

  15. Inductively Shorted Bicone Fed Tapered Dipole Antenna

    Science.gov (United States)

    2012-05-23

    Switching from a balun feed to a coaxial cable feed showed expected similar impedances for the shorted antenna with number 14 wire shorts. Switching ...possibility is to add broadband ferrite core chokes placed about the shorts 70 near their ends 50, 52, 54, 56, 58, 60 ,62, 64 to prevent antenna...currents from flowing onto the shorts. Some problems with this method are that ferrites have loss and limited bandwidth, and the resulting floating

  16. Antenna Miniaturization in Complex Electromagnetic Environments

    DEFF Research Database (Denmark)

    Zhang, Jiaying

    Hearing-aids today constitute devices with an advanced technology, and wireless communication integrated into hearing-aids will introduce a range of completely new functionalities. The antenna is an important component in any wireless system, and the demand for compact wireless systems with strin......Hearing-aids today constitute devices with an advanced technology, and wireless communication integrated into hearing-aids will introduce a range of completely new functionalities. The antenna is an important component in any wireless system, and the demand for compact wireless systems...... improved compared to the 2-D planar electrically small loop antennas. Measurement Techniques for ESAs In this dissertation we proposed two novel measurement techniques for electrically small antennas. A modified Wheeler cap method for the radiation efficiency measurement of balanced electrically small....... Moreover, the modified Wheeler cap method for measurements of small antennas in complex environments is further developed. A cable-free impedance and gain measurement technique for electrically small antennas is also proposed. The electromagnetic model of this technique is derived by using the spherical...

  17. Phased Array Transmit Antenna for a Satellite

    Science.gov (United States)

    Huggins, R. W.; Heisen, P. T.; Miller, G. E.; McMeen, D. J.; Perko, K. L.

    1999-01-01

    Active phased array antennas with electronically scanned beams offer advantages over high gain parabolic dish antennas currently used on spacecraft. Benefits include the elimination of deployable structures, no moving parts, and no torque disturbances that moving antennas impart to the spacecraft. The latter results in the conservation of spacecraft power, and the ability to take precision optical data while transmitting data. Such an antenna has been built under a contract from NASA Goddard Space Flight Center for the New Millennium Program EO- 1 satellite where it will act as the primary highspeed scientific data communication link. The antenna operates at X-band, has an integral controller and power conditioner, communicates with the spacecraft over a 1773 optical data bus, and is space qualified for low earth orbit (705 Km altitude). The nominal mission length is one year, and the operational requirement is for one 10 minute transmission a day over Spitsbergen, Norway. Details of the antenna and its performance will be described in the following paper.

  18. Optical antennas with sinusoidal modulation in width.

    Science.gov (United States)

    Dikken, Dirk Jan; Segerink, Frans B; Korterik, Jeroen P; Pfaff, Stefan S; Prangsma, Jord C; Herek, Jennifer L

    2016-08-08

    Small metal structures sustaining plasmon resonances in the optical regime are of great interest due to their large scattering cross sections and ability to concentrate light to subwavelength volumes. In this paper, we study the dipolar plasmon resonances of optical antennas with a constant volume and a sinusoidal modulation in width. We experimentally show that by changing the phase of the width-modulation, with a small 10 nm modulation amplitude, the resonance shifts over 160 nm. Using simulations we show how this simple design can create resonance shifts greater than 600 nm. The versatility of this design is further shown by creating asymmetric structures with two different modulation amplitudes, which we experimentally and numerically show to give rise to two resonances. Our results on both the symmetric and asymmetric antennas show the capability to control the localization of the fields outside the antenna, while still maintaining the freedom to change the antenna resonance wavelength. The antenna design we tested combines a large spectral tunability with a small footprint: all the antenna dimensions are factor 7 to 13 smaller than the wavelength, and hold potential as a design element in meta-surfaces for beam shaping.

  19. Electromagnetic field of a linear antenna

    Science.gov (United States)

    Derby, Norman; Olbert, Stanislaw

    2008-11-01

    Animated computer simulations of the electric field of a radiating antenna can capture the attention of students in introductory electromagnetism courses and stimulate active discussions. The simulations raise questions not usually addressed in textbooks. In certain cases, some of the field lines appear to move toward the antenna, the speed of the field lines can change as they move, and the field lines exhibit strange behavior (circling or splitting) at certain points. Because their fields can be expressed in terms of elementary functions, animations of point dipole antennas are common, but animations showing the fields of antennas with more realistic lengths are not as common because analytical expressions for these fields are not as well known. We show that it is possible to derive analytical expressions in terms of elementary functions for the electromagnetic field of linear antennas of finite length. We draw attention to an open-source method for displaying the fine details within the field patterns and then give a general discussion of singular points and their motions, derive expressions for their location and phase velocity, and apply these results to some of the phenomena that are visible in visualizations of the fields of various antennas.

  20. Comparison of Antenna Measurement Facilities with the DTU-ESA 12 GHz Validation Standard Antenna within the EU Antenna Centre of Excellence

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Pallesen, Janus Engberg; Breinbjerg, Olav

    2009-01-01

    The primary objective of many antenna measurement facilities is to provide a specified high accuracy of the measured data. The validation of an antenna measurement facility is the process of proving that such a specified accuracy can be achieved. Since this constitutes a very challenging task......, antenna measurement accuracy has been the subject of much research over many years and a range of useful measures have been introduced. Facility comparisons, together with antenna standards, error budgets, facility accreditations, and measurement procedure standards, constitute an effective measure...... towards facility validations. This paper documents the results of a comparison between 8 European antenna measurement facilities with a specially designed reference antenna, the DTU-ESA 12 GHz Validation Standard Antenna (VAST-12). The electrical and mechanical properties of the VAST-12 antenna...

  1. MUTUAL COUPLING REDUCTION BETWEEN MICROSTRIP ANTENNAS USING ELECTROMAGNETIC BANDGAP STRUCTURE

    Directory of Open Access Journals (Sweden)

    G.N. Gaikwad

    2011-03-01

    Full Text Available When the number of antenna elements is placed in forming the arrays, mutual coupling between the antenna elements is a critical issue. This is particularly concern in phase array antennas. Mutual coupling is a potential source of performance degradation in the form of deviation of the radiation pattern from the desired one, gain reduction due to excitation of surface wave, increased side lobe levels etc. EBG (Electromagnetic Band Gap structure (also called as Photonic Bandgap Structure PBG not only enhances the performance of the patch antennas but also provides greater amount of isolation when placed between the microstrip arrays. This greatly reduces the mutual coupling between the antenna elements. The radiation efficiency, gain, antenna efficiency, VSWR, frequency, directivity etc greatly improves over the conventional patch antennas using EBG. The EBG structure and normal patch antenna is simulated using IE3D antenna simulation software.

  2. Design of Monopole Antenna Based on Fractal Geometry

    Directory of Open Access Journals (Sweden)

    Zhao Yuanqing

    2014-01-01

    Full Text Available This paper presents a circular disc monopole antenna based on fractal geometry. The antenna is designed to be applied in UWB systems. So it is essential to ensure that the bandwidth of the antenna ranges from 3.1 GHz to 10.6 GHz, that is, IEEE 802.15.3a. However, the proposed antenna has achieved working in the required bandwidth. Compared to the antennas illustrated in most similar literatures, the proposed antenna has a much smaller size, which makes the antenna possible to be integrated with portable devices. Firstly, the antenna was designed through CST Microwave Studio. Then, the antenna was fabricated according to the simulated results. At last, the comparison between the simulated results and measured results was carried out which demonstrated good consistency.

  3. Improvement of Power Efficiency using Smart Antenna System in MANETs

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar

    2014-11-01

    Full Text Available Performance of ad-hoc networks is low under omnidirectional antenna systems compared to smart antenna system. Directional antennas cover large area {&} save some amount of transmitted power because it focuses in desired direction accordance with mobility of nodes while Omni-directional antennas cover small area {&} needs large transmitted power as compared to Smart Antenna System (SAS. In this paper, we will overcome the problem of unnecessary transmitted power wastage with omnidirectional antenna system in ad-hoc wireless networks by using Smart Antenna Systems (SAS. We will calculate {&} analyze transmitted power variations with different number of mobile nodes in mobile ad-hoc networks [MANETs] with smart antenna system (SAS {&} Omni-directional antenna system in different conditions. Firstly, we will calculate {&} analyze transmitted power during flooding of packets means in case of route creation, and secondly, when communication will established between transmitter {&} receiver

  4. Analysis of equivalent antenna based on FDTD method

    Institute of Scientific and Technical Information of China (English)

    Yun-xing YANG; Hui-chang ZHAO; Cui DI

    2014-01-01

    An equivalent microstrip antenna used in radio proximity fuse is presented. The design of this antenna is based on multilayer multi-permittivity dielectric substrate which is analyzed by finite difference time domain (FDTD) method. Equivalent iterative formula is modified in the condition of cylindrical coordinate system. The mixed substrate which contains two kinds of media (one of them is air)takes the place of original single substrate. The results of equivalent antenna simulation show that the resonant frequency of equivalent antenna is similar to that of the original antenna. The validity of analysis can be validated by means of antenna resonant frequency formula. Two antennas have same radiation pattern and similar gain. This method can be used to reduce the weight of antenna, which is significant to the design of missile-borne antenna.

  5. Competitive Use of Multiple Antennas

    CERN Document Server

    Vaze, Rahul

    2011-01-01

    A game theoretic framework is presented to analyze the problem of finding the optimal number of data streams to transmit in a multi-user MIMO scenario, where both the transmitters and receivers are equipped with multiple antennas. Without channel state information (CSI) at any transmitter, and using outage capacity as the utility function with zero-forcing receiver, each user is shown to transmit a single data stream at Nash equilibrium in the presence of sufficient number of users. Transmitting a single data stream is also shown to be optimal in terms of maximizing the sum of the outage capacities in the presence of sufficient number of users. With CSI available at each transmitter, and using the number of successful bits per Joule of energy as the utility function, at Nash equilibrium, each user is shown to transmit a single data stream on the best eigen-mode that requires the least transmit power to achieve a fixed signal-to-interference ratio. Using the concept of locally gross direction preserving maps, ...

  6. Investigation of Diagonal Antenna-Chassis Mode in Mobile Terminal LTE MIMO Antennas for Bandwidth Enhancement

    DEFF Research Database (Denmark)

    Zhang, Shuai; Zhao, Kun; Ying, Zhinong

    2015-01-01

    A diagonal antenna-chassis mode is investigated in long-term evolution multiple-input-multiple-output (LTE MIMO) antennas. The MIMO bandwidth is defined in this paper as the overlap range of the low-envelope correlation coefficient, high total efficiency, and -6-dB impedance matching bandwidths...

  7. Synthesis of Antenna Arrays and Parasitic Antenna Arrays with Mutual Couplings

    Directory of Open Access Journals (Sweden)

    M. Thevenot

    2012-01-01

    Full Text Available A synthesis method to design multielement antennas with couplings is presented. The main objective is to perform a rigorous determination of the electromagnetic characteristics involved in the design, especially with arrays of moderate sizes. The aim is to conceive jointly and efficiently the antenna and the circuits to connect (feed distribution network, power amplifiers, reactive loads, etc.. The subsequent objective is to improve the understanding and capabilities of strongly coupled antennas. As a whole, the synthesis procedure is then applied to different antenna architectures in order to show its efficiency and versatility. A focus on some antenna concepts where the management of couplings is a key factor to improve the performances is presented. After describing the synthesis procedure, the first category of coupled multielement antenna studied concerns radiating arrays in linear or circular polarization. A design including couplings effects on an active array is also presented. Then, the method is applied to parasitic antenna arrays and a specific investigation on reflectarray antenna is performed as they can be considered as a particular case of parasitic arrays.

  8. Application of the SWE-to-PWE antenna diagnostics technique to an offset reflector antenna

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Frandsen, A; Breinbjerg, Olav

    2007-01-01

    A new antenna diagnostics technique has been developed for the DTU-ESA Spherical Near-Field Antenna Test Facility at the Technical University of Denmark. The technique is based on the transformation of the Spherical Wave Expansion (SWE) of the radiated field, obtained from a spherical near...... will be detected in the antenna far-field pattern, and the accuracy and ability of the diagnostics technique to subsequently identify them will be investigated. Real measurement data will be employed for each test case....... measurement accuracy, have been reported previously, we validate here the new antenna diagnostics technique through an experimental investigation of a commercially available offset reflector antenna, where a tilt of the feed and surface distortions are intentionally introduced. The effects of these errors...

  9. Beamforming and Antenna Grouping Design for the Multi-Antenna Relay with Energy Harvesting to Improve Secrecy Rate

    Directory of Open Access Journals (Sweden)

    Weijia Lei

    2016-07-01

    Full Text Available The physical security strategy in the wireless network with a single-antenna eavesdropper is studied. The information transmits from a single-antenna source to a single-antenna destination, and an energy-limited multi-antenna relay is employed to forward information. The antennas of the relay are divided into two groups. One group receives and forwards information, and the other converts the received signal into energy. Beamforming is used by the relay to prevent the eavesdropper from intercepting confidential information. For the purpose of maximizing the secrecy rate, antenna grouping and beamforming vectors are designed. A low complexity scheme of antenna grouping is presented. The simulation results show that the secrecy rate can be significantly improved by arranging part of the antennas for energy harvesting, and part for forwarding and optimizing the beamforming vector at the relay. The antenna grouping scheme significantly reduces the computational complexity at the cost of acceptable performance loss.

  10. Inkjet-Printed Ultra Wide Band Fractal Antennas

    KAUST Repository

    Maza, Armando Rodriguez

    2012-05-01

    In this work, Paper-based inkjet-printed Ultra-wide band (UWB) fractal antennas are presented. Three new designs, a combined UWB fractal monopole based on the fourth order Koch Snowflake fractal which utilizes a Sierpinski Gasket fractal for ink reduction, a Cantor-based fractal antenna which performs a larger bandwidth compared to previously published UWB Cantor fractal monopole antenna, and a 3D loop fractal antenna which attains miniaturization, impedance matching and multiband characteristics. It is shown that fractals prove to be a successful method of reducing fabrication cost in inkjet printed antennas while retaining or enhancing printed antenna performance.

  11. Planar MIMO Antenna with Slits for WBAN Applications

    Directory of Open Access Journals (Sweden)

    Do-Gu Kang

    2014-01-01

    Full Text Available A planar MIMO antenna with slits for WBAN applications is proposed. The antenna consists of two PIFAs, ground pads, and two slits. By adding ground pads, the antenna size is reduced with improved impedance matching. Through two slits in a ground plane, the isolation characteristic is improved and the resonant frequency can be controlled. To analyze the antenna performance on a human body, the proposed antenna on a human equivalent flat phantom is investigated through simulations. Regardless of the existence of the phantom, the antenna operates in 2.4 GHz ISM band with the isolation higher than 18 dB.

  12. Satellite antenna layout and optimization in electromagnetic compatibility design

    Science.gov (United States)

    Zhang, Jinshuo; Xie, Shuguo; Liu, Yan

    2009-12-01

    This paper firstly analyzes the main factors that impact the layout of satellite antenna. The uniform geometrical theory of diffraction (UTD) is used to establish mathematical model for calculating the coupling of satellite antenna, and set up the objective function of the placement optimization. The genetic algorithm incorporating high-frequency simulation to minimize antenna coupling by optimally positioning satellite antenna is described in detail. The results of antenna placement on a realistic satellite show that this method is effective in the optimal design of satellite antenna layout for the purpose of electromagnetic compatibility.

  13. Reliable Control of Ship-mounted Satellite Tracking Antenna

    DEFF Research Database (Denmark)

    Soltani, Mohsen; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

    2010-01-01

    Motorized antenna is a key element in overseas satellite telecommunication. The control system directs the on-board antenna toward a chosen satellitewhile the high sea waves disturb the antenna. Certain faults (communication system malfunction or signal blocking) cause interruption in the communi......Motorized antenna is a key element in overseas satellite telecommunication. The control system directs the on-board antenna toward a chosen satellitewhile the high sea waves disturb the antenna. Certain faults (communication system malfunction or signal blocking) cause interruption...

  14. Logo Antenna for 5.8 GHz Wireless Communications

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A logo antenna for the 5.8 GHz ISM band is presented. The idea behind the logo antenna is to use the company or university logo as part of the antenna. When disguised as a logo, it may be more acceptable to place the antenna at optimal locations to obtain good coverage. In the present work...... the university logo has been used. The designed logo antenna has a measured and simulated 3-dB bandwidth of 153.1 MHz (2.6%) and 165.6 MHz (2.9%), respectively. The aperture fed, omnidirectional logo antenna is little hand sensitive....

  15. Logo Antenna for 5.8 GHz Wireless Communications (invited)

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A logo antenna for the 5.8 GHz ISM band is presented. The idea behind the logo antenna is to use the company or university logo as part of the antenna. When disguised as a logo, it may be more acceptable to place the antenna at optimal locations to obtain good coverage. In the present work...... the university logo has been used. The designed logo antenna has a measured and simulated 3-dB bandwidth of 153.1 MHz (2.6%) and 165.6 MHz (2.9%), respectively. The aperture fed, omnidirectional logo antenna is little hand sensitive....

  16. Numerical Simulation of Plasma Antenna with FDTD Method

    Institute of Scientific and Technical Information of China (English)

    LIANG Chao; XU Yue-Min; WANG Zhi-Jiang

    2008-01-01

    We adopt cylindrical-coordinate FDTD algorithm to simulate and analyse a 0.4-m-long column configuration plasma antenna. FDTD method is useful for solving electromagnetic problems, especially when wave characteristics and plasma properties are self-consistently related to each other. Focus on the frequency from 75 MHz to 400 MHz, the input impedance and radiation efficiency of plasma antennas are computed. Numerical results show that, different from copper antenna, the characteristics of plasma antenna vary simultaneously with plasma frequency and collision frequency. The property can be used to construct dynamically reconfigurable antenna.The investigation is meaningful and instructional for the optimization of plasma antenna design.

  17. Aperture coupled stacked patch antenna for dual band

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar Vishwakarma

    2012-06-01

    Full Text Available -Microstrip antennas (MAS are very useful antenna where low profile antennas are required. They are most popular due to their small size, low cost, light weight. The first aperture coupled microstrip antenna was introduced in 1985 by D M Pozar. Aperture coupled antenna is a particular antenna with high gain and wide bandwidth. This paper presents aperture coupled stacked patch antenna using air gap variation. The variation of air gap [2mm to 6mm] has been done between single patch antenna and an aperture coupled antenna. The main advantage of this antenna to increase the band width of the antenna as compared with single layered patch antenna. The resonant frequencies changes with air gap variations. The feed can be done either a conventional coaxial probe or through a coupling aperture in the ground plane as we done. This antenna works well in the frequency range (2.9 GHz to 6.0 GHz. The measured return loss exhibit an impedance bandwidth of 35%.The input impedance and VSWR return loss have been measured with the help of Network analyzer. [Agilent E8363B A.04.06] From the measured result it is found that the value of VSWR corresponding lower resonance frequencies increases from 14 to 2.2 with increasing air gap variation where as at the upper resonance frequencies is also increased from 1.8 to 2.3.

  18. Design of Frequency Tunable Compact Antenna and Millimeter to Terahertz Array Antennas

    Science.gov (United States)

    Damman, Rafid Noel

    As increased bandwidth demands continue to rise and overly crowded existing bands need be relieved, the study of frequency tunable and higher frequency array antennas is needed. By tuning the resonant frequency of an antenna, the bandwidth increases since the operating frequency has increased from the tuning. Also, higher frequency antenna designs are beginning to take flight to alleviate the lower bands and allow for an increase in bandwidth. Both the methods can bring a solution to the increased bandwidth demand. Thesis work begins with the design of a novel single feed planar antenna with 4G tunable bands and consistent upper LTE bands. This antenna is simulated using full wave analysis tool, fabricated and measured. This antenna shows near omni-directional radiation pattern exhibiting gain levels from -4.25dBi in the lower band to 2.69dBi in the upper band. The impedance matching for the lower band can be tuned from 690 MHz - 970 MHz while the higher band is consistently present between 1.29 GHz - 2.05 GHz, both based on S 11 ≤ - 6dBi. To begin the stepping stone for higher frequency planar array antenna designs, first an 8x8 array antenna is designed in the Ka band. The impedance matching for this design is measured 28.34 GHz - 32.09 GHz having fractional bandwidth of 12.41% based on S11 ? - 10dB. This array antenna was fabricated and experimentally verified for its impedance matching and radiation performances. Next, a 4x4 antenna array is designed for operation in the 5G wireless band and using 0.07mm quartz material. The design has matching band from 53.6 GHz - 54.0 GHz having fractional bandwidth of 0.7435% based on S 11 ≤ -10dB. Finally, a 2x2 array antenna having a center frequency of 300 GHz with fractional bandwidth of 11.2% based on S11 ≤ -10dB is designed. This 2x2 array antenna was also designed using 0.07mm thick quartz substrate material so as to fabricate using the photolithography method due to the limitations of the standard method of

  19. First two ALMA antennas successfully linked

    Science.gov (United States)

    2009-05-01

    Scientists and engineers working on the world's largest ground-based astronomical project, the Atacama Large Millimeter/submillimeter Array (ALMA), have achieved another milestone -- the successful linking of two ALMA astronomical antennas, synchronised with a precision of one millionth of a millionth of a second -- to observe the planet Mars. ALMA is under construction by an international partnership in the Chilean Andes. ESO PR Photo 18a/09 The two ALMA antennas On 30 April, the team observed the first "interferometric fringes" of an astronomical source by linking two 12-metre diameter ALMA antennas, together with the other critical parts of the system. Mars was chosen as a suitable target for the observations, which demonstrate ALMA's full hardware functionality and connectivity. This important milestone was achieved at the ALMA Operations Support Facility, high in Chile's Atacama region, at an altitude of 2900 metres. "We're very proud and excited to have made this crucial observation, as it proves that the various hardware components work smoothly together. This brings us another step closer to full operations for ALMA as an astronomical observatory," says Wolfgang Wild, the European ALMA Project Manager. The two antennas used in this test will be part of ALMA's array of 66 giant 12-metre and 7-metre diameter antennas that will observe in unison as a single giant telescope, under construction on the Chajnantor plateau above the Operations Support Facility, at an altitude of 5000 metres. ALMA will operate as an interferometer, capturing millimetre and submillimetre wavelength signals from the sky with multiple antennas, and combining them to create extremely high resolution images, similar to those that would be obtained by a single, giant antenna with a diameter equal to the distance between the antennas used. "This can only be achieved with the perfect synchronisation of the antennas and the electronic equipment: a precision much better than one millionth of

  20. Plasmonic antennas hybridized with dielectric waveguides.

    Science.gov (United States)

    Bernal Arango, Felipe; Kwadrin, Andrej; Koenderink, A Femius

    2012-11-27

    For the purpose of using plasmonics in an integrated scheme where single emitters can be probed efficiently, we experimentally and theoretically study the scattering properties of single nanorod gold antennas as well as antenna arrays placed on one-dimensional dielectric silicon nitride waveguides. Using real space and Fourier microscopy correlated with waveguide transmission measurements, we quantify the spectral properties, absolute strength, and directivity of scattering. The scattering processes can be well understood in the framework of the physics of dipolar objects placed on a planar layered environment with a waveguiding layer. We use the single plasmonic structures on top of the waveguide as dipolar building blocks for new types of antennas where the waveguide enhances the coupling between antenna elements. We report on waveguide hybridized Yagi-Uda antennas which show directionality in out-coupling of guided modes as well as directionality for in-coupling into the waveguide of localized excitations positioned at the feed element. These measurements together with simulations demonstrate that this system is ideal as a platform for plasmon quantum optics schemes as well as for fluorescence lab-on-chip applications.

  1. A Compact Multiband Notch UWB Antenna

    Directory of Open Access Journals (Sweden)

    K. Kumar

    2012-01-01

    Full Text Available A simple and a compact coplanar waveguide (CPW ultrawide band (UWB antenna is presented. Multiband stop function is achieved by two different types of band stop resonators. One is a tilted square spiral slot resonator of different size and length etched on the patch and the other is a coupled resonator etched on the ground plane. These resonators provide considerable increase in notch bandwidth at the stop bands. The proposed antenna has a total size of 18×20.3 mm2. The designed antenna achieves pass band performance at 1.8–2.1 GHz (15.38%, 3.0–3.2 GHz (6.45%, 4.4–4.7 GHz (6.59%, 6.3-6.4 GHz (1.57%, and 8–11.2 GHz (33.33% where VSWR <2 and four stop bands at 2.4–2.8 GHz (15.38%, 3.2–3.7 GHz (14.49%, 5.5–6 GHz (8.69%, and 6.5–7 GHz (7.40% where VSWR is equal to 10. The antenna has a peak gain of 3.8 dBi. The measured results show that the antenna achieves good impedance matching and consistent radiation patterns over an operating bandwidth.

  2. Synthesis of multiple shaped beam antenna patterns

    Science.gov (United States)

    Stutzman, W. L.; Coffey, E. L.

    1973-01-01

    Results are presented of research into the problem of finding an excitation of a given antenna such that the desired radiation pattern is approximated to within acceptable limits. This is to be done in such a fashion that boundary conditions involving hardware limitations may be inserted into the problem. The intended application is synthesis of multiple shaped beam antennas. Since this is perhaps the most difficult synthesis problem an antenna engineer is likely to encounter, the approach taken was to include as a by-product capability for synthesizing simpler patterns. The synthesis technique has been almost totally computerized. The class of antennas which may be synthesized with the computer program are those which may be represented as planar (continuous or discrete) current distributions. The technique is not limited in this sense and could indeed by extended to include, for example, the synthesis of conformal arrays or current distributions on the surface of reflectors. The antenna types which the program is set up to synthesize are: line source, rectangular aperture, circular aperture, linear array, rectangular array, and arbitrary planar array.

  3. Metamaterial Inspired Microstrip Antenna Investigations Using Metascreens

    Directory of Open Access Journals (Sweden)

    Muhammad Tauseef Asim

    2015-01-01

    Full Text Available A dual layer periodically patterned metamaterial inspired antenna on a low cost FR4 substrate is designed, simulated, fabricated, and tested. The eigenmode dispersion simulations are performed indicating the left handed metamaterial characteristics and are tunable with substrate permittivity. The same metamaterial unit cell structure is utilized to fabricate a metascreen. This metascreen is applied below the proposed metamaterial antenna and next used as superstrate above a simple patch to study the effects on impedance bandwidth, gain, and radiation patterns. The experimental results of these antennas are very good and closely match with the simulations. More importantly, the resonance for the proposed metamaterial antenna with metascreen occurs at the left handed (LH eigenfrequency of the metamaterial unit cell structure. The measured −10 dB bandwidths are 14.56% and 22.86% for the metamaterial antenna with single and double metascreens, respectively. The metascreens over the simple patch show adjacent dual band response. The first and second bands have measured −10 dB bandwidths of 9.6% and 16.66%. The simulated peak gain and radiation efficiency are 1.83 dBi and 74%, respectively. The radiation patterns are also very good and could be useful in the UWB wireless applications.

  4. Experimental Results of Schlicher's Thrusting Antenna

    Science.gov (United States)

    Fralick, Gustave C.; Niedra, Janis M.

    2001-01-01

    Experiments were conducted to test the claims by Rex L. Schlicher, et al., (Patent 5,142,86 1) that a certain antenna geometry produces thrust greatly exceeding radiation reaction, when driven by repetitive, fast rise, and relatively slower decay current pulses. In order to test this hypothesis, the antenna was suspended by strings as a 3 in pendulum. Current pulses were fed to the antenna along the suspension path by a very flexible coaxial line constructed from loudspeaker cable and copper braid sheath. When driving the antenna via this cabling, our pulser was capable of sustaining 1200 A pulses at a rate of 30 per second up to a minute. In this way, bursts of pulses could be delivered in synch with the pendulum period in order to build up any motion. However, when using a laser beam passing through a lens attached to the antenna to amplify linear displacement by a factor of at least 25, no correlated motion of the beam spot could be detected on a distant wall. We conclude, in agreement with the momentum theorem of classical electromagnetic theory, that any thrust produced is far below practically useful levels. Hence, within classical electrodynamics, there is little hope of detecting any low level motion that cannot be explained by interactions with surrounding structural steel and the Earth's magnetic field.

  5. Low Cost Antennas for Direct Broadcast Satellite Radio

    Science.gov (United States)

    Wu, T. K.; Huang, J.

    1994-01-01

    Two omni-directional and circularly polarized low gain antennas (the crossed drooping dipole and the TM(sub 21) mode circular patch antenna)are developed for direct broadcast satellite radio (DBSR) outdoor mobile terminal applications.

  6. Efficient Wearable Antennas for Astronaut EVA Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA SBIR Subtopic O1.02 (Antenna Technology), Pharad proposes to create a new class of highly efficient body wearable antennas suitable for astronaut...

  7. On Connectivity of Wireless Sensor Networks with Directional Antennas

    Science.gov (United States)

    Wang, Qiu; Dai, Hong-Ning; Zheng, Zibin; Imran, Muhammad; Vasilakos, Athanasios V.

    2017-01-01

    In this paper, we investigate the network connectivity of wireless sensor networks with directional antennas. In particular, we establish a general framework to analyze the network connectivity while considering various antenna models and the channel randomness. Since existing directional antenna models have their pros and cons in the accuracy of reflecting realistic antennas and the computational complexity, we propose a new analytical directional antenna model called the iris model to balance the accuracy against the complexity. We conduct extensive simulations to evaluate the analytical framework. Our results show that our proposed analytical model on the network connectivity is accurate, and our iris antenna model can provide a better approximation to realistic directional antennas than other existing antenna models. PMID:28085081

  8. On Connectivity of Wireless Sensor Networks with Directional Antennas

    Directory of Open Access Journals (Sweden)

    Qiu Wang

    2017-01-01

    Full Text Available In this paper, we investigate the network connectivity of wireless sensor networks with directional antennas. In particular, we establish a general framework to analyze the network connectivity while considering various antenna models and the channel randomness. Since existing directional antenna models have their pros and cons in the accuracy of reflecting realistic antennas and the computational complexity, we propose a new analytical directional antenna model called the iris model to balance the accuracy against the complexity. We conduct extensive simulations to evaluate the analytical framework. Our results show that our proposed analytical model on the network connectivity is accurate, and our iris antenna model can provide a better approximation to realistic directional antennas than other existing antenna models.

  9. Tri-band small monopole antenna based on SRR units

    Science.gov (United States)

    Shehata, Gehan; Mohanna, Mahmoud; Rabeh, Mohammed Lotfy

    2015-12-01

    In this paper a novel design for a tri-band monopole antenna coupled with metamaterial units is introduced. The proposed antenna was designed to cover WiMAX (2.5, 3.5) and WLAN (5.2) bands. In our proposal, a coplanar waveguide (CPW) fed circular-disk monopole antenna is coupled with three split ring resonator (SRR) units which exist on its back side. In our design a monopole antenna and SRR units are designed first to resonate at 5.2 GHz and 2.5 GHz respectively. In addition, antenna is loaded with post to force resonance at 3.5 GHz. SRR units are used for 2.5 GHz resonance to miniaturize antenna size, and our proposed antenna considered an electrically small antenna (ESA) at its first resonance frequency. Simulated and measured results exhibit a good agreement that validate our design.

  10. Tri-band small monopole antenna based on SRR units

    Directory of Open Access Journals (Sweden)

    Gehan Shehata

    2015-12-01

    Full Text Available In this paper a novel design for a tri-band monopole antenna coupled with metamaterial units is introduced. The proposed antenna was designed to cover WiMAX (2.5, 3.5 and WLAN (5.2 bands. In our proposal, a coplanar waveguide (CPW fed circular-disk monopole antenna is coupled with three split ring resonator (SRR units which exist on its back side. In our design a monopole antenna and SRR units are designed first to resonate at 5.2 GHz and 2.5 GHz respectively. In addition, antenna is loaded with post to force resonance at 3.5 GHz. SRR units are used for 2.5 GHz resonance to miniaturize antenna size, and our proposed antenna considered an electrically small antenna (ESA at its first resonance frequency. Simulated and measured results exhibit a good agreement that validate our design.

  11. Slow-plasmon resonant nano-strip antennas

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Beermann, Jonas; Boltasseva, Alexandra

    2008-01-01

    Resonant scattering by gold nanostrip antennas due to constructive interference of counterpropagating slow surface plasmon polaritons SPPs is analyzed, including the quasistatic limit of ultrasmall antennas, and experimentally demonstrated. The phase of slow SPP reflection by strip ends is found...

  12. On Connectivity of Wireless Sensor Networks with Directional Antennas.

    Science.gov (United States)

    Wang, Qiu; Dai, Hong-Ning; Zheng, Zibin; Imran, Muhammad; Vasilakos, Athanasios V

    2017-01-12

    In this paper, we investigate the network connectivity of wireless sensor networks with directional antennas. In particular, we establish a general framework to analyze the network connectivity while considering various antenna models and the channel randomness. Since existing directional antenna models have their pros and cons in the accuracy of reflecting realistic antennas and the computational complexity, we propose a new analytical directional antenna model called the iris model to balance the accuracy against the complexity. We conduct extensive simulations to evaluate the analytical framework. Our results show that our proposed analytical model on the network connectivity is accurate, and our iris antenna model can provide a better approximation to realistic directional antennas than other existing antenna models.

  13. A tunable microwave slot antenna based on graphene

    Energy Technology Data Exchange (ETDEWEB)

    Dragoman, Mircea; Aldrigo, Martino; Vasilache, D.; Dinescu, A. [National Institute for Research and Development in Microtechnology (IMT), Str. Erou Iancu Nicolae 126 A, 077190 Bucharest-Voluntari (Romania); Neculoiu, Dan; Bunea, Alina-Cristina, E-mail: alina.bunea@imt.ro [National Institute for Research and Development in Microtechnology (IMT), Str. Erou Iancu Nicolae 126 A, 077190 Bucharest-Voluntari (Romania); “Politehnica” University of Bucharest, Bd. Iuliu Maniu 1-3, 061071, Bucharest (Romania); Deligeorgis, George; Konstantinidis, George [Foundation for Research and Technology Hellas (FORTH), P.O. Box 1527, Vassilika Vuton, Heraklion 71110, Crete, Hellas (Greece); Mencarelli, Davide; Pierantoni, Luca [Università Politecnica delle Marche, via Brecce Bianche 12, 60131 Ancona (Italy); Modreanu, M. [Tyndall National Institute, Lee Maltings Complex, Dyke Parade, Cork (Ireland)

    2015-04-13

    The paper presents the experimental and modeling results of a microwave slot antenna in a coplanar configuration based on graphene. The antennas are fabricated on a 4 in. high-resistivity Si wafer, with a ∼300 nm SiO{sub 2} layer grown through thermal oxidation. A CVD grown graphene layer is transferred on the SiO{sub 2}. The paper shows that the reflection parameter of the antenna can be tuned by a DC voltage. 2D radiation patterns at various frequencies in the X band (8–12 GHz) are then presented using as antenna backside a microwave absorbent and a metalized surface. Although the radiation efficiency is lower than a metallic antenna, the graphene antenna is a wideband antenna while the metal antennas with the same geometry and working at the same frequencies are narrowband.

  14. Slow-plasmon resonant-nanostrip antennas: Analysis and demonstration

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Beermann, J.; Boltasseva, Alexandra;

    2008-01-01

    Resonant scattering by gold nanostrip antennas due to constructive interference of counterpropagating slow surface plasmon polaritons (SPPs) is analyzed, including the quasistatic limit of ultrasmall antennas, and experimentally demonstrated. The phase of slow SPP reflection by strip ends is found...

  15. Improved Low-Profile Helical Antenna Design for INMARSAT Applications

    Directory of Open Access Journals (Sweden)

    Shiqiang Fu

    2012-01-01

    Full Text Available A new low-profile variable pitch angle cylindrical helical antenna employing a copper strip as impedance transformer is proposed in this paper. Under the circumstance of a limited antenna height, the circular polarization performance of the antenna has been enhanced by changing the pitch angle and the input impedance matching has been improved by adjusting the copper strip match stub. The design method of the proposed antenna is given. The optimal antenna structure for INMARSAT application has been fabricated and measured. The measured results show that in the whole maritime satellite communication work band the VSWR is less than 1.2, its antenna gain is higher than 9 dBi, and the axial ratio is lower than 2.5 dB. The experimental results have a good agreement with the simulations. The proposed antenna is compact and easy tuning. It provides a promising antenna element for maritime satellite communication applications.

  16. Antenna arrays. Citations from the NTIS data base

    Science.gov (United States)

    Reed, W. E.

    1980-04-01

    A bibliography containing 161 abstracts concerning the use of antenna arrays in the fields of radar, communications, radio astronomy, navigation, electronic countermeasures, and spacecraft is presented. Topics include design, antenna radiation patterns, mathematical models, and performance.

  17. Angle-resolved polarimetry measurements of antenna-mediated fluorescence

    CERN Document Server

    Mohtashami, Abbas; Koenderink, A Femius

    2015-01-01

    Optical phase-array antennas can be used to control not only the angular distribution but also the polarization of fluorescence from quantum emitters. The emission pattern of the resulting system is determined by the properties of the antenna, the properties of the emitters and the strength of the antenna-emitter coupling. Here we show that Fourier polarimetry can be used to characterize these three contributions. To this end, we measured the angle and Stokes-parameter resolved emission of bullseye plasmon antennas as well as spiral antennas excited by an ensemble of emitters. We estimate the antenna-emitter coupling on basis of the degree of polarization, and determine the effect of anisotropy in the intrinsic emitter orientation on polarization of the resulting emission pattern. Our results not only provide new insights in the behavior of bullseye and spiral antennas, but also demonstrate the potential of Fourier polarimetry when characterizing antenna mediated fluorescence.

  18. Mutual coupling in MIMO antennas with transceiver separation

    DEFF Research Database (Denmark)

    Pelosi, Mauro; Knudsen, Miakel B.; Pedersen, Gert Frølund

    2011-01-01

    In multiple antenna systems mutual coupling needs to be minimized. We propose an alternative novel decoupling technique, investigating several multiple antenna configurations for small handsets through measurements and numerical simulations. The influence of different novel designs on performance...

  19. Shuttle Millimeter Wave Communications Experiment (MWCE) antenna system development

    Science.gov (United States)

    1978-01-01

    An antenna system requirements report is presented. Topics reported include: (1) antenna system specifications; (2) waveguide circuitry; (3) feed horn design; (4) dish reflectors; (5) gimbal systems; and (6) summary of system design.

  20. Millimeter-wave and terahertz integrated circuit antennas

    Science.gov (United States)

    Rebeiz, Gabriel M.

    1992-01-01

    This paper presents a comprehensive review of integrated circuit antennas suitable for millimeter and terahertz applications. A great deal of research was done on integrated circuit antennas in the last decade and many of the problems associated with electrically thick dielectric substrates, such as substrate modes and poor radiation patterns, have been understood and solved. Several new antennas, such as the integrated horn antenna, the dielectric-filled parabola, the Fresnel plate antenna, the dual-slot antenna, and the log-periodic and spiral antennas on extended hemispherical lenses, have resulted in excellent performance at millimeter-wave frequencies, and are covered in detail in this paper. Also, a review of the efficiency definitions used with planar antennas is given in detail in the appendix.

  1. Computational Investigation of Microstrip Antennas in Plasma Environment

    CERN Document Server

    Vyas, Hardik; Gupta, Sanjeev

    2016-01-01

    Microstrip antennas are extensively used in spacecraft systems and other applications where they encounter a plasma environment. A detailed computational investigation of change in antenna radiation properties in the presence of plasma has been presented in this paper. The study shows antenna properties such as the resonant frequency, return loss, radiation properties and the different characteristics of the antenna changes when it is surrounded by plasma. Particular focus of the work is to understand the causes behind these changes by correlating the complex propagation constant in the plasma medium, field distribution on the patch and effective dielectric of the antenna substrate with antenna parameter variations. The study also provides important insights to explore the possibilities of designing tunable microstrip antenna where the substrate can be replaced with plasma and important antenna characteristics can be controlled by varying the plasma density.

  2. Design and optimization of LTE 1800 MIMO antenna.

    Science.gov (United States)

    Wong, Huey Shin; Islam, Mohammad Tariqul; Kibria, Salehin

    2014-01-01

    A multiple input and multiple output (MIMO) antenna that comprises a printed microstrip antenna and a printed double-L sleeve monopole antenna for LTE 1800 wireless application is presented. The printed double-L sleeve monopole antenna is fed by a 50 ohm coplanar waveguide (CPW). A novel T-shaped microstrip feedline printed on the other side of the PCB is used to excite the waveguide's outer shell. Isolation characteristics better than -15 dB can be obtained for the proposed MIMO antenna. The proposed antenna can operate in LTE 1800 (1710 MHz-1880 MHz). This antenna exhibits omnidirectional characteristics. The efficiency of the antenna is greater than 70% and has high gain of 2.18 dBi.

  3. Beam-Steerable Flat-Panel Reflector Antenna

    Science.gov (United States)

    Lee, Choon Sae; Lee, Chanam; Miranda, Felix A.

    2005-01-01

    Many space applications require a high-gain antenna that can be easily deployable in space. Currently, the most common high-gain antenna for space-born applications is an umbrella-type reflector antenna that can be folded while being lifted to the Earth orbit. There have been a number of issues to be resolved for this type of antenna. The reflecting surface of a fine wire mesh has to be light in weight and flexible while opening up once in orbit. Also the mesh must be a good conductor at the operating frequency. In this paper, we propose a different type of high-gain antenna for easy space deployment. The proposed antenna is similar to reflector antennas except the curved main reflector is replaced by a flat reconfigurable surface for easy packing and deployment in space. Moreover it is possible to steer the beam without moving the entire antenna system.

  4. Planar Ultrawideband Antenna with Photonically Controlled Notched Bands

    Directory of Open Access Journals (Sweden)

    Drasko Draskovic

    2013-01-01

    Full Text Available A design of a planar microstrip-fed ultrawideband (UWB printed circular monopole antenna with optically controlled notched bands is presented. The proposed antenna is composed of a circular ultrawideband patch, with an etched T-shaped slot controlled by an integrated silicon switch. The slot modifies the frequency response of the antenna suppressing 3.5–5 GHz band when the switch is in open state. The optical switch is controlled by a low-power near-infrared (808 nm laser diode, which causes the change in the frequency response of the antenna generating a frequency notch. This solution could be expanded to include several notches in the antenna frequency response achieving a fully reconfigurable UWB antenna. The antenna could be remotely controlled at large distances using optical fiber. The prototype antenna has been fully characterized to verify these design concepts.

  5. Wireless communication system via nanoscale plasmonic antennas.

    Science.gov (United States)

    Merlo, Juan M; Nesbitt, Nathan T; Calm, Yitzi M; Rose, Aaron H; D'Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R; Burns, Michael J; Kempa, Krzysztof; Naughton, Michael J

    2016-08-24

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology.

  6. Novel antenna concepts via coordinate transformation

    Directory of Open Access Journals (Sweden)

    P.-H. Tichit

    2013-02-01

    Full Text Available Coordinate transformation is an emerging field which offers a powerful and unprecedented ability to manipulate and control electromagnetic waves. Using this tool, we demonstrate the design of novel antenna concepts by tailoring their radiation properties. The wave manipulation is enabled through the use of engineered dispersive composite metamaterials that realize the space coordinate transformation. Three types of antennas are considered for design: a directive, a beam steerable and a quasi-isotropic one. Numerical simulations together with experimental measurements are performed in order to validate the coordinate transformation concept. Near-field cartography and far-field pattern measurements performed on a fabricated prototype agree qualitatively with Finite Element Method (FEM simulations. It is shown that a particular radiation pattern can be tailored at ease into a desired one by modifying the electromagnetic properties of the space around radiator. This idea opens the way to novel antenna design techniques for various application domains such as the aeronautical and transport fields.

  7. Antenna optimization using Particle Swarm Optimization algorithm

    Directory of Open Access Journals (Sweden)

    Golubović Ružica M.

    2006-01-01

    Full Text Available We present the results for two different antenna optimization problems that are found using the Particle Swarm Optimization (PSO algorithm. The first problem is finding the maximal forward gain of a Yagi antenna. The second problem is finding the optimal feeding of a broadside antenna array. The optimization problems have 6 and 20 optimization variables, respectively. The preferred values of the parameters of the PSO algorithm are found for presented problems. The results show that the preferred parameters of PSO are somewhat different for optimization problems with different number of dimensions of the optimization space. The results that are found using the PSO algorithm are compared with the results that are found using other optimization algorithms, in order to estimate the efficiency of the PSO.

  8. Antenna-coupled microcavities for terahertz emission

    Energy Technology Data Exchange (ETDEWEB)

    Madéo, J., E-mail: Julien.madeo@univ-paris-diderot.fr; Todorov, Y.; Sirtori, C. [Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, UMR7162, 75013 Paris (France)

    2014-01-20

    We have investigated the capacitive coupling between dipolar antennas and metal-dielectric-metal wire microcavities with strong sub-wavelength confinement in the terahertz region. The coupling appears in reflectivity measurements performed on arrays of antenna-coupled elements, which display asymmetric Fano lineshapes. The experimental data are compared to a temporal coupled-mode theory and finite elements electromagnetic simulations. We show that the Fano interferences correspond to coupling between a subradiant mode (microcavity) and a superradiant mode (antennas). This phenomenon allows one to enhance and control the radiative coupling of the strongly confined mode with the vacuum. These concepts are very useful for terahertz optoelectronic devices based on deep-sub-wavelength active regions.

  9. Statistical monitoring of linear antenna arrays

    KAUST Repository

    Harrou, Fouzi

    2016-11-03

    The paper concerns the problem of monitoring linear antenna arrays using the generalized likelihood ratio (GLR) test. When an abnormal event (fault) affects an array of antenna elements, the radiation pattern changes and significant deviation from the desired design performance specifications can resulted. In this paper, the detection of faults is addressed from a statistical point of view as a fault detection problem. Specifically, a statistical method rested on the GLR principle is used to detect potential faults in linear arrays. To assess the strength of the GLR-based monitoring scheme, three case studies involving different types of faults were performed. Simulation results clearly shown the effectiveness of the GLR-based fault-detection method to monitor the performance of linear antenna arrays.

  10. Q factors for antennas in dispersive media

    CERN Document Server

    Gustafsson, Mats; Cismasu, Marius

    2014-01-01

    Stored energy and Q-factors are used to quantify the performance of small antennas. Accurate and efficient evaluation of the stored energy is also essential for current optimization and the associated physical bounds. Here, it is shown that the frequency derivative of the input impedance and the stored energy can be determined from the frequency derivative of the electric field integral equation. The expressions for the differentiated input impedance and stored energies differ by the use of a transpose and Hermitian transpose in the quadratic forms. The quadratic forms also provide simple single frequency formulas for the corresponding Q-factors. The expressions are further generalized to antennas integrated in temporally dispersive media. Numerical examples that compare the different Q-factors are presented for dipole and loop antennas in conductive, Debye, Lorentz, and Drude media. The computed Q-factors are also verified with the Q-factor obtained from the stored energy in Brune synthesized circuit models.

  11. Compact acoustic antenna design using labyrinthine metamaterials

    Science.gov (United States)

    Ren, Chunyu

    2015-05-01

    We present an effective design and architecture for a class of acoustic antennas in air. The work begins with a conformal transformation method that yields the preliminary design, which is constructed using an isotropic but inhomogeneous material. However, the desired material parameters have been unavailable until now. Here we show that by scaling up the refractive index and optimizing the geometry in the preliminary design, a series of square antennas can be achieved to exhibit an excellent beam-collimating effect. An important part of our strategy is that the device's thickness and material properties can be tailored easily to greatly facilitate its realization. It is also demonstrated that the proposed antenna can be made very thin and readily implemented using labyrinthine acoustic metamaterials.

  12. Lower Hybrid antennas for nuclear fusion experiments

    CERN Document Server

    Hillairet, Julien; Bae, Young-Soon; Bai, X; Balorin, C; Baranov, Y; Basiuk, V; Bécoulet, A; Belo, J; Berger-By, G; Brémond, S; Castaldo, C; Ceccuzzi, S; Cesario, R; Corbel, E; Courtois, X; Decker, J; Delmas, E; Delpech, L; Ding, X; Douai, D; Ekedahl, A; Goletto, C; Goniche, M; Guilhem, D; Hertout, P; Imbeaux, F; Litaudon, X; Magne, R; Mailloux, J; Mazon, D; Mirizzi, F; Mollard, P; Moreau, P; Oosako, T; Petrzilka, V; Peysson, Y; Poli, S; Preynas, M; Prou, M; Saint-Laurent, F; Samaille, F; Saoutic, B

    2015-01-01

    The nuclear fusion research goal is to demonstrate the feasibility of fusion power for peaceful purposes. In order to achieve the conditions similar to those expected in an electricity-generating fusion power plant, plasmas with a temperature of several hundreds of millions of degrees must be generated and sustained for long periods. For this purpose, RF antennas delivering multi-megawatts of power to magnetized confined plasma are commonly used in experimental tokamaks. In the gigahertz range of frequencies, high power phased arrays known as "Lower Hybrid" (LH) antennas are used to extend the plasma duration. This paper reviews some of the technological aspects of the LH antennas used in the Tore Supra tokamak and presents the current design of a proposed 20 MW LH system for the international experiment ITER.

  13. An antenna model for the Purcell effect.

    Science.gov (United States)

    Krasnok, Alexander E; Slobozhanyuk, Alexey P; Simovski, Constantin R; Tretyakov, Sergei A; Poddubny, Alexander N; Miroshnichenko, Andrey E; Kivshar, Yuri S; Belov, Pavel A

    2015-08-10

    The Purcell effect is defined as a modification of the spontaneous emission rate of a quantum emitter at the presence of a resonant cavity. However, a change of the emission rate of an emitter caused by an environment has a classical counterpart. Any small antenna tuned to a resonance can be described as an oscillator with radiative losses, and the effect of the environment on its radiation can be modeled and measured in terms of the antenna radiation resistance, similar to a quantum emitter. We exploit this analogue behavior to develop a general approach for calculating the Purcell factors of different systems and various frequency ranges including both electric and magnetic Purcell factors. Our approach is illustrated by a general equivalent scheme, and it allows resenting the Purcell factor through the continuous radiation of a small antenna at the presence of an electromagnetic environment.

  14. Maximum Throughput in Multiple-Antenna Systems

    CERN Document Server

    Zamani, Mahdi

    2012-01-01

    The point-to-point multiple-antenna channel is investigated in uncorrelated block fading environment with Rayleigh distribution. The maximum throughput and maximum expected-rate of this channel are derived under the assumption that the transmitter is oblivious to the channel state information (CSI), however, the receiver has perfect CSI. First, we prove that in multiple-input single-output (MISO) channels, the optimum transmission strategy maximizing the throughput is to use all available antennas and perform equal power allocation with uncorrelated signals. Furthermore, to increase the expected-rate, multi-layer coding is applied. Analogously, we establish that sending uncorrelated signals and performing equal power allocation across all available antennas at each layer is optimum. A closed form expression for the maximum continuous-layer expected-rate of MISO channels is also obtained. Moreover, we investigate multiple-input multiple-output (MIMO) channels, and formulate the maximum throughput in the asympt...

  15. E-SHAPED STACKED BROADBAND PATCH ANTENNA

    Directory of Open Access Journals (Sweden)

    Bharat Rochani

    2014-10-01

    Full Text Available A coaxial feed modified E-shaped patch antenna has been presented with parametric study of the antenna parameters. The proposed antenna is designed for WLAN and WiMAX applications from 5 – 6 GHz. The 5 – 6 GHz band has been chosen because it provides higher data rate (>50 Mbps for laptops, note-book computers and many new wireless digital applications devices without interference. Although current 5.0 GHz wireless computer network systems operated from 5.15 GHz – 5.35 GHz band. But in future, for faster data rate 5.725 – 5.85 GHz band becomes popular in addition to 5.15 – 5.35 GHz.

  16. Screen printed UHF antennas on flexible substrates

    Science.gov (United States)

    Janeczek, Kamil; Młożniak, Anna; Kozioł, Grażyna; Araźna, Aneta; Jakubowska, Małgorzata; Bajurko, Paweł

    2010-09-01

    Printed electronics belongs to the most important developing electronics technologies. It provides new possibilities to produce low cost and large area devices. In its range several applications can be distinguished like printed batteries, OLED, biosensors, photovoltaic cells or RFID tags. In the presented investigation, antennas working in UHF frequency range were elaborated. It can be applied in the future for flexible RFID tags. To produce these antennas polymer paste with silver flakes was used. It was deposited on two flexible substrates (foil and photo paper) with screen printing techniques. After printing process surface profile, electrical and microwave parameters of performed antennas were measured using digital multimeter and network analyzer, relatively. Furthermore, a thickness of printed layers was measured.

  17. Terahertz antenna technology for space applications

    CERN Document Server

    Choudhury, Balamati; Jha, Rakesh Mohan

    2016-01-01

    This book explores the terahertz antenna technology towards implementation of compact, consistent and cheap terahertz sources, as well as the high sensitivity terahertz detectors. The terahertz EM band provides a transition between the electronic and the photonic regions thus adopting important characteristics from these regimes. These characteristics, along with the progress in semiconductor technology, have enabled researchers to exploit hitherto unexplored domains including satellite communication, bio-medical imaging, and security systems. The advances in new materials and nanostructures such as graphene will be helpful in miniaturization of antenna technology while simultaneously maintaining the desired output levels. Terahertz antenna characterization of bandwidth, impedance, polarization, etc. has not yet been methodically structured and it continues to be a major research challenge. This book addresses these issues besides including the advances of terahertz technology in space applications worldwide,...

  18. Wireless communication system via nanoscale plasmonic antennas

    Science.gov (United States)

    Merlo, Juan M.; Nesbitt, Nathan T.; Calm, Yitzi M.; Rose, Aaron H.; D'Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R.; Burns, Michael J.; Kempa, Krzysztof; Naughton, Michael J.

    2016-08-01

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology.

  19. Antenna model of the Purcell effect

    CERN Document Server

    Krasnok, Alexander E; Simovski, Constantin R; Tretyakov, Sergei A; Poddubny, Alexander N; Miroshnichenko, Andrey E; Kivshar, Yuri S; Belov, Pavel A

    2015-01-01

    The Purcell effect - the modification of the spontaneous emission rate in presence of resonant cavities or other resonant objects - is a fundamental effect of quantum electrodynamics. However, a change of the emission rate caused by environment different from free space has a classical counterpart. Not only quantum emitters, but any small antenna tuned to the resonance is an oscillator with radiative losses, and the influence of the environment on its radiation can be understood and measured in terms of the antenna radiation resistance. We present a general approach which is applicable to measurements of the Purcell factor for radio antennas and to calculations of these factors for quantum emitters. Our methodology is suitable for calculation and measurement of both electric and magnetic Purcell factors, it is versatile and applies to various frequency ranges. The approach is illustrated by a general equivalent scheme and allows the Purcell factor to be expressed through the continious radiation of a small an...

  20. Non-foster matching of an RFID antenna

    KAUST Repository

    Mohamed Hassan Salem, Nedime Pelin

    2011-07-01

    Novel designs of radio-frequency identification (RFID) tag antennas with better matching characteristics to achieve extended range for passive tags are investigated in ultra-high frequency (UHF) band. A microstrip dipole antenna with or without an integrated negative impedance converter designed to cancel out the antenna\\'s input capacitance at resonance frequency was designed, simulated, constructed and measured for implementation in RFID applications. © 2011 IEEE.

  1. Arrays of recycled power TM polarized nano-antennas.

    Science.gov (United States)

    Hattori, Haroldo T; Li, Ziyuan

    2013-07-15

    In recent years, plasmonic nano-antennas have been used in a wide range of applications in sensing, particle detection, imaging and Surface Enhanced Raman Scattering (SERS) detection. Also, arrays of nano-antennas have been recently developed to produce more directional radiation beams or to operate over a wide range of wavelengths. In this article, it is shown that small arrays of nano-antennas can be created by recycling the power that flows through their antenna gaps.

  2. Radar antenna pointing for optimized signal to noise ratio.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter; Marquette, Brandeis

    2013-01-01

    The Signal-to-Noise Ratio (SNR) of a radar echo signal will vary across a range swath, due to spherical wavefront spreading, atmospheric attenuation, and antenna beam illumination. The antenna beam illumination will depend on antenna pointing. Calculations of geometry are complicated by the curved earth, and atmospheric refraction. This report investigates optimizing antenna pointing to maximize the minimum SNR across the range swath.

  3. UHF Antenna Design for AFIT Random Noise Radar

    Science.gov (United States)

    2012-03-01

    printed circuit board antenna construction methods. The antipodal chopped Vivaldi dipole antenna, built with a milling machine, v achieved a wider... circuit board antenna (right) ............................................................. 2 Figure 2 – CST Simulated S11 parameter of the LPA...79 xii Figure 60 – Surface current (10.6 GHz) of antipodal CVD antenna from Yang et al [1] (4.5cm x 4.6cm, 50Ω microstrip feed

  4. An Efficient Beam Steerable Antenna Array Concept for Airborne Applications

    OpenAIRE

    Aliakbarian, H.; Van der Westhuizen, E.; Wiid, R.; Volskiy, V.; R. Wolhuter; G. A. E. Vandenbosch

    2014-01-01

    Deployment of a satellite borne, steerable antenna array with higher directivity and gain in Low Earth Orbit makes sense to reduce ground station complexity and cost, while still maintaining a reasonable link budget. The implementation comprises a digitally beam steerable phased array antenna integrated with a complete system, comprising the antenna, hosting platform, ground station, and aircraft based satellite emulator to facilitate convenient aircraft based testing of the antenna array and...

  5. Theoretical analysis of a parabolic torus reflector antenna with multibeam

    Institute of Scientific and Technical Information of China (English)

    杜彪; 杨可忠; 钟顺时

    1995-01-01

    The parametric equations and the formulas of unit normal vector and surface element for aparabolic torus reflector antenna are derived and the mechanism of producing multibeam is proposed, Based on physical optics, the radiation pattern formulas for the antenna are given, with which the effects of geometric parameters on the antenna are studied. The good agreement between the calculated patterns and the measured ones shows that the theory is helpful for designing parabolic torus antennas.

  6. Metamaterial-inspired SRR-based Small Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    A self-resonant miniaturized antenna composed of a broadside-coupled split ring resonator (SRR) and an excitation truncated loop is presented. Being λ0/17 in size the antenna is tuned to 50 Ohms without any matching network.......A self-resonant miniaturized antenna composed of a broadside-coupled split ring resonator (SRR) and an excitation truncated loop is presented. Being λ0/17 in size the antenna is tuned to 50 Ohms without any matching network....

  7. Loaded antenna in half lossy space base on HDGA

    Institute of Scientific and Technical Information of China (English)

    SUN Guo-xi; YIN Jun-xun

    2005-01-01

    Antenna loads can modify the current distribution on the wires, thus improving antenna characteristics in the process. However, it is difficult to calculate appropriate loads of antenna near the ground because in half lossy space there are inherent situational complexities. This paper optimizes loads of antenna near the ground base using a half-determined genetic algorithm. The numerical results show the HDGA has a quicker convergent speed and a better convergent value than the SGA.

  8. Researches on Reconfigurable Antenna in CEMLAB at UESTC

    Institute of Scientific and Technical Information of China (English)

    WANG Bing-zhong; XIAO Shao-qiu; ZHANG Yong; YANG Xue-song; WU Wei-xia

    2006-01-01

    This paper summarizes the achievement and progress in the research on reconfigurable antenna since 2001, in Computational Electromagnetics Laboratory (CEMLAB) at University of Electronic Science and Technology of China (UESTC). Several typical reconfigurable antennas are introduced, which can realize frequency, pattern or frequency-pattern reconfigurability by electrically controlling methods. Some techniques involved in the design and analysis of reconfigurable antennas are reported. At last, the development trend of reconfigurable antenna is predicted in the conclusions.

  9. Phased Antenna Array for Global Navigation Satellite System Signals

    Science.gov (United States)

    Turbiner, Dmitry (Inventor)

    2015-01-01

    Systems and methods for phased array antennas are described. Supports for phased array antennas can be constructed by 3D printing. The array elements and combiner network can be constructed by conducting wire. Different parameters of the antenna, like the gain and directivity, can be controlled by selection of the appropriate design, and by electrical steering. Phased array antennas may be used for radio occultation measurements.

  10. Dipole-on-dielectric model for infrared lithographic spiral antennas

    Energy Technology Data Exchange (ETDEWEB)

    Boreman, G.D. [Center for Research and Education in Optics and Lasers and Department of Electrical Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Dogariu, A. [Center for Research and Education in Optics and Lasers, University of Central Florida, Orlando, Florida 32816 (United States); Christodoulou, C. [Department of Electrical Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Kotter, D. [Idaho National Engineering Laboratory, Lockheed-Martin Corporation, P.O. Box 1625, Idaho Falls, Idaho 83415 (United States)

    1996-03-01

    We present a dipole-on-dielectric model for lithographic antennas used for bolometer coupling in the infrared. The predicted antenna patterns show good agreement with measurements of Au-on-Si spiral antennas at 9.5-{mu}m wavelength. Angle- and polarization-resolved measurements are proposed, which will further probe the behavior of these antenna structures and facilitate refinement of the analytical models. {copyright} {ital 1996 Optical Society of America.}

  11. Downsizing Antenna Technologies for Mobile and Satellite Communications

    Science.gov (United States)

    Huang, J.; Densmore, A.; Tulintseff, A.; Jamnejad, V.

    1993-01-01

    Due to the increasing and stringent functional requirements (larger capacity, longer distances, etc.) of modern day communication systems, higher antenna gains are generally needed. This higher gain implies larger antenna size and mass which are undesirable to many systems. Consequently, downsizing antenna technology becomes one of the most critical areas for research and development efforts. Techniques to reduce antenna size can be categorized and are briefly discussed.

  12. Antenna subset selection at multi-antenna relay with adaptive modulation

    KAUST Repository

    Choi, Seyeong

    2011-06-01

    In this paper, we proposed several antenna selection schemes for cooperative diversity systems with adaptive transmission. The proposed schemes were based on dual-hop relaying where a relay with multiple-antenna capabilities at reception and transmission is deployed between the source and the destination nodes. We analyzed the performance of the proposed schemes by quantifying the average spectral efficiency and the outage probability. We also investigated the trade-off of performance and complexity by comparing the average number of active antennas, path estimations, and signal-to-noise ratio comparisons of the different proposed schemes. Copyright © 2011 John Wiley & Sons, Ltd.

  13. A Liquid Metal Conical Helical Antenna for Circular Polarization-Reconfigurable Antenna

    OpenAIRE

    Yun Zhou; Shaojun Fang; Hongmei Liu; Shiqiang Fu

    2016-01-01

    A novel polarization-reconfigurable conical helical antenna based on the liquid metal is presented. The antenna is implemented by using truncated structure, variable pitch angle, a matching stub, and a mechanical autorotation device. The experimental results show that a good agreement between simulations and measurements is obtained. The gain of the antenna achieves higher than 8 dBi in the work band (1525–1660.5 MHz), and the 3 dB axial ratio (AR) bandwidth reaches 410 MHz. The polarization ...

  14. MEMS-Reconfigurable Metamaterials and Antenna Applications

    Directory of Open Access Journals (Sweden)

    Tomislav Debogovic

    2014-01-01

    Full Text Available This paper reviews some of our contributions to reconfigurable metamaterials, where dynamic control is enabled by microelectromechanical systems (MEMS technology. First, we show reconfigurable composite right-/left-handed transmission lines (CRLH-TLs having state of the art phase velocity variation and loss, thereby enabling efficient reconfigurable phase shifters and leaky-wave antennas (LWA. Second, we present very low loss metasurface designs with reconfigurable reflection properties, applicable in reflectarrays and partially reflective surface (PRS antennas. All the presented devices have been fabricated and experimentally validated. They operate in X- and Ku-bands.

  15. ANTENNAS ARRAY ADJUST WITH ADAPTIVE NEURONAL SYSTEM

    Directory of Open Access Journals (Sweden)

    A. Padrón

    2004-12-01

    Full Text Available In this work an array failure correction for Linear Antenna Array (LAA is presented. This is carried out by means ofan Adaptive Artificial Neural Network (AANN that adjusts the amplitude and phase at beamforming. Theappropriated corrections are given, when one, or two, or three elements have a failure in the antenna linear array.The AANN corrects the corresponding parameters in the radiation pattern obtained due to the failure, when weknow the coefficients of the array factor (AF. This yields a reduction of side lobe level and some interferencesdisappear.

  16. Topology Optimization of Sub-Wavelength Antennas

    DEFF Research Database (Denmark)

    Erentok, Aycan; Sigmund, Ole

    2011-01-01

    We propose a topology optimization strategy for the systematic design of a three-dimensional (3D), conductor-based sub-wavelength antenna. The post-processed finite-element (FE) models of the optimized structure are shown to be self-resonant, efficient and exhibit distorted omnidirectional......, elliptically polarized far-field radiation patterns. The computed approximate Q value for this antenna is QZ(ω0)≈ 7.74 for ω0=2π × 350.8 MHz and it is 1.64 times larger than the theoretical lower bound value....

  17. Visualization Of Electromagnetic Environment Near GSM Antennae

    Science.gov (United States)

    Zvezdina, M. Yu; Shokova, Yu A.; Kundryukova, N. I.; Kutukova, V. D.; Pozdnyakova, A. V.

    2017-01-01

    Web-enabled mobile phone enhancement has determined a sharp increase of mobile base station quantity, which has led to a surge of electromagnetic noise in metropolitan areas. Electromagnetic noise permanently influences adult and child population; the impossibility to remove this impact has promoted the electromagnetic monitoring. The most accessible form of socially oriented monitoring is a visualization of energy flux density for GSM base station antennae. Forecast calculation routines take antenna construction and location into an account; they also allow giving the recommendations on electromagnetic environment improvement basing on physical interpretation the obtained results.

  18. Development of a microstrip UHF conformal antenna

    Science.gov (United States)

    Shields, M. W.; Cassell, R. B.

    1977-01-01

    Low profile, engineering model EMU antennas were constructed. Final data for these antennas meet most of the electrical requirements in a 6 in. x 18 in. x 1.4 in. package which weighs under 2.0 lbs. Coverage data calculated at the design frequencies very nearly meets the design goal of providing a gain greater than or equal to -10 dBi over 80% of a sphere. Recommendations are made for future work directed toward producing an efficient quality design capable of operating in a space environment.

  19. FORTE antenna element and release mechanism design

    Energy Technology Data Exchange (ETDEWEB)

    Rohweller, D.J. [Astro Aerospace Corp., Carpinteria, CA (United States); Butler, T.Af. [Los Alamos National Lab., NM (United States)

    1995-02-01

    The Fast On-Orbit Recording of Transient Events (FORTE) satellite being built by Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) has as its most prominent feature a large deployable (11 m by 5 m) log periodic antenna to monitor emissions from electrical storms on the Earth. This paper describes the antenna and the design for the long elements and explains the dynamics of their deployment and the damping system employed. It also describes the unique paraffin-actuated reusable tie-down and release mechanism employed in the system.

  20. Static analysis of synchronism deployable antenna

    Institute of Scientific and Technical Information of China (English)

    GUAN Fu-ling; SHOU Jian-jun; HOU Guo-yong; ZHANG Jing-jie

    2006-01-01

    A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This antenna consists oftetrahedral elements from central element. Because there are springs at the ends of some of the rods, spider joints are applied. For analysis purpose, the structure is simplified and modelled by using 2D beam elements that have no bending stiffness. Displacement vectors are defined to include two translational displacements and one torsional displacement. The stiffness matrix derived by this method is relatively simple and well defined. The analysis results generated by using software developed by our research group agreed very well with available test data.

  1. Split ring resonator resonance assisted terahertz antennas

    CERN Document Server

    Galal, Hossam; Vitiello, Miriam S

    2016-01-01

    We report on the computational development of novel architectures of low impedance broadband antennas, for efficient detection of Terahertz (THz) frequency beams. The conceived Split Ring Resonator Resonance Assisted (SRR RA) antennas are based on both a capacitive and inductive scheme, exploiting a 200 Ohm and 400 Ohm impedance, respectively. Moreover, the impedance is tunable by varying the coupling parameters in the exploited geometry, allowing for better matching with the detector circuit for maximum power extraction. Our simulation results have been obtained by assuming a 1.5 THz operation frequency.

  2. Parasitic antenna arrays for wireless MIMO systems

    CERN Document Server

    Kanatas, Athanasios; Papadias, Constantinos

    2014-01-01

    This  book covers a cross-section of two technologies: parasitic antenna arrays driven via analogue circuits; and MIMO technology for multi-antenna arrays.  The combination of these two technologies results in novel functionality. Relevant technical angles, ranging from theoretic to electromagnetic considerations; from analogue circuit to digital baseband control for signal generation; and from channel modeling to communication theoretic aspects are detailed by the contributors. Potential applications are considered in conjunction with current and upcoming wireless standards is provided.

  3. An LTCC 94 GHz Antenna Array

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, J; Pao, H; Lin, H; Garland, P; O' Neill, D; Horton, K

    2007-12-21

    An antenna array is designed in low-temperature cofired ceramic (LTCC) Ferro A6M{trademark} for a mm-wave application. The antenna is designed to operate at 94 GHz with a few percent bandwidth. A key manufacturing technology is the use of 3 mil diameter vias on a 6 mil pitch to construct the laminated waveguides that form the beamforming network and radiating elements. Measurements for loss in the laminated waveguide are presented. The slot-fed cavity-radiating element is designed to account for extremely tight mutual coupling between elements. The array incorporates a slot-fed multi-layer beamforming network.

  4. ALMA Observatory Equipped with its First Antenna

    Science.gov (United States)

    2008-12-01

    High in the Atacama region of northern Chile one of the world’s most advanced telescopes has just passed a major milestone. The first of many state-of-the-art antennas has been handed over to the Atacama Large Millimeter/submillimeter Array (ALMA) project. ALMA is being built by a global partnership whose North American partners are led by the National Radio Astronomy Observatory (NRAO). With ALMA, astronomers will study the cool Universe, the molecular gas and tiny dust grains from which stars, planetary systems, galaxies and even life are formed. ALMA will provide new, much-needed insights into the formation of stars and planets, and will reveal distant galaxies in the early Universe, which we see as they were over ten billion years ago. ALMA will initially comprise 66 high-precision antennas, with the option to expand in the future. There will be an array of fifty 12-meter diameter antennas, acting together as a single giant telescope, and a compact array composed of 7-meter and 12-meter antennas. The first 12-meter antenna to be handed over to the observatory was built by Mitsubishi Electric Corporation for the National Astronomical Observatory of Japan, one of the ALMA partners. It will shortly be joined by North American and European antennas. “Our Japanese colleagues have produced this state-of-the-art antenna to exacting specifications. We are very excited about the handover because now we can fully equip this antenna for scientific observations,” said Thijs de Graauw, ALMA Director. Antennas arriving at the ALMA site undergo a series of tests to ensure that they meet the strict requirements of the telescope. The antennas have surfaces accurate to less than the thickness of a human hair, and can be pointed precisely enough to pick out a golf ball at a distance of 9 miles. “The handover of the first Japanese antenna is the crowning achievement of the ALMA Project to date,” said Adrian Russell, the North American ALMA Project Director at NRAO. The

  5. Antenna Design for Diversity and MIMO Application

    DEFF Research Database (Denmark)

    Ying, Zhinong; Chiu, Chi-Yuk; Zhao, Kun

    2015-01-01

    Recently, multiple-input multiple-output (MIMO) technology and diversity have attracted much attention both in industry and academia due to high data rate and high spectrum efficiency. By increasing the number of antennas at the transmitter and/or the receiver side of the wireless link, the diver......Recently, multiple-input multiple-output (MIMO) technology and diversity have attracted much attention both in industry and academia due to high data rate and high spectrum efficiency. By increasing the number of antennas at the transmitter and/or the receiver side of the wireless link...

  6. Frequency-agile antennas for wireless communications

    CERN Document Server

    Petosa, Aldo

    2013-01-01

    Mobile data subscriptions are expected to more than double and mobile wireless traffic to increase by more than tenfold over the next few years. Proliferation of smart phones, tablets, and other portable devices are placing greater demands for services such as web browsing, global positioning, video streaming, and video telephony. Many of the proposed solutions to deal with these demands will have a significant impact on antenna designs. Antennas with frequency agility are considered a promising technology to help implement these new solutions.This book provides readers with a sense of the cap

  7. Lightweight, Self-Deploying Foam Antenna Structures

    Science.gov (United States)

    Sokolowski, Witold; Levin, Steven; Rand, Peter

    2004-01-01

    Lightweight, deployable antennas for a variety of outer-space and terrestrial applications would be designed and fabricated according to the concept of cold hibernated elastic memory (CHEM) structures, according to a proposal. Mechanically deployable antennas now in use are heavy, complex, and unreliable, and they utilize packaging volume inefficiently. The proposed CHEM antenna structures would be simple and would deploy themselves without need for any mechanisms and, therefore, would be more reliable. The proposed CHEM antenna structures would also weigh less, could be packaged in smaller volumes, and would cost less, relative to mechanically deployable antennas. The CHEM concept was described in two prior NASA Tech Briefs articles: "Cold Hibernated Elastic Memory (CHEM) Expandable Structures" (NPO-20394), Vol. 23, No. 2 (February 1999), page 56; and "Solar Heating for Deployment of Foam Structures" (NPO-20961), Vol. 25, No. 10 (October 2001), page 36. To recapitulate from the cited prior articles: The CHEM concept is one of utilizing opencell foams of shape-memory polymers (SMPs) to make lightweight, reliable, simple, and inexpensive structures that can be alternately (1) compressed and stowed compactly or (2) expanded, then rigidified for use. A CHEM structure is fabricated at full size from a block of SMP foam in its glassy state [at a temperature below the glass-transition temperature (Tg) of the SMP]. The structure is heated to the rubbery state of the SMP (that is, to a temperature above Tg) and compacted to a small volume. After compaction, the structure is cooled to the glassy state of the SMP. The compacting force can then be released and the structure remains compact as long as the temperature is kept below Tg. Upon subsequent heating of the structure above Tg, the simultaneous elastic recovery of the foam and its shape-memory effect cause the structure to expand to its original size and shape. Once thus deployed, the structure can be rigidified by

  8. Cylindrical metamaterial-based subwavelength antenna

    DEFF Research Database (Denmark)

    Erentok, Aycan; Kim, Oleksiy S.; Arslanagic, Samel

    2009-01-01

    A subwavelength monopole antenna radiating in the presence of a truncated cylindrical shell, which has a capped top face and is made of a negative permittivity metamaterial, is analyzed numerically by a method of moments for the volume-surface integral equation oil the one hand, and a finite...... element method on the other hand. It is shown that a center-fed truncated cylinder, in contrast to an infinite cylinder, provides subwavelength resonances, thus suggesting the possibility, of having a subwavelength antenna system....

  9. Antenna standards and laboratories in Europe

    DEFF Research Database (Denmark)

    Lemanczyk, Jerzy

    1994-01-01

    The goal of this paper is to present an overview on antenna standards and laboratories within Europe. In this context, Europe will be limited geographically to the member nations of the European Union (EU), formerly the European Community, and the European Space Agency (ESA). In addition to these......The goal of this paper is to present an overview on antenna standards and laboratories within Europe. In this context, Europe will be limited geographically to the member nations of the European Union (EU), formerly the European Community, and the European Space Agency (ESA). In addition...

  10. MEMS-reconfigurable metamaterials and antenna applications

    CERN Document Server

    Debogovic, Tomislav

    2014-01-01

    This paper reviews some of our contributions to reconfigurable metamaterials, where dynamic control is enabled by micro-electro-mechanical systems (MEMS) technology. First, we show reconfigurable composite right/left handed transmission lines (CRLH-TLs) having state of the art phase velocity variation and loss, thereby enabling efficient reconfigurable phase shifters and leaky-wave antennas (LWA). Second, we present very low loss metasurface designs with reconfigurable reflection properties, applicable in reflectarrays and partially reflective surface (PRS) antennas. All the presented devices have been fabricated and experimentally validated. They operate in X- and Ku-bands.

  11. Explore the Capability of ESPAR Antennas for Low Cost Communication

    DEFF Research Database (Denmark)

    Han, Bo; Kalis, A; Papadias, C.;

    ESPAR antenna systems are composed of one active and several parasitic elements and by changing the characteristic of the parasitic elements on the antenna, the radiation pattern will also change. Such characteristic makes ESPAR antenna useful in many applications, e.g., single RF MIMO transmissi...

  12. Rapid Prototyping of Electrically Small Spherical Wire Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2014-01-01

    It is shown how modern rapid prototyping technologies can be applied for quick and inexpensive, but still accurate, fabrication of electrically small wire antennas. A well known folded spherical helix antenna and a novel spherical zigzag antenna have been fabricated and tested, exhibiting the imp...

  13. Electrically Small Magnetic Dipole Antennas with Magnetic Core

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2010-01-01

    This work extends the theory of a spherical magnetic dipole antenna with magnetic core by numerical results for practical antenna configurations that excite higher-order modes besides the main TE10 spherical mode. The multiarm spherical helix (MSH) and the spherical split ring (SSR) antennas...

  14. Architectures for ku-band broadband airborne satellite communication antennas

    NARCIS (Netherlands)

    Verpoorte, Jaco; Schippers, Harmen; Jorna, Pieter; Roeloffzen, Chris G.H.; Marpaung, David A.I.; Baggen, Rens; Sanadgol, Bahram

    2010-01-01

    This paper describes different architectures for a broadband antenna for satellite communication on aircraft. The antenna is a steerable (conformal) phased array antenna in Ku-band (receive-only). First the requirements for such a system are addressed. Subsequently a number of potential architecture

  15. Approximate Methods in the Analysis of Conformal Array Antennas

    NARCIS (Netherlands)

    Visser, H.J.; Gerini, G.

    2000-01-01

    Conformal array antennas are required whenever an antenna must be located on a vehicle, e.g. the skin of an aircraft, missile or superstructure of a ship. Conforming the array antenna to the existing structure avoids compromising aerodynamic or stealth characteristics, but at the cost of an increase

  16. Field Of View Of A Spacecraft Antenna: Analysis And Software

    Science.gov (United States)

    Wu, Te-Kao; Kipp, R.; Lee, S. W.

    1995-01-01

    Report summarizes computational analysis of field of view of rotating elliptical-cross-section parabolic-reflector antenna for SeaWinds spacecraft. Issues considered include blockage and diffraction by other objects near antenna, related concerns about electromagnetic interference and electromagnetic compatibility, and how far and in which configuration other objects positioned with respect to antenna to achieve required performance.

  17. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual-pola...

  18. Planar Near-Field Measurements of Ground Penetrating Radar Antennas

    DEFF Research Database (Denmark)

    Meincke, Peter; Hansen, Thorkild

    2004-01-01

    Planar near-field measurements are formulated for a general ground penetrating radar (GPR) antenna. A total plane-wave scattering matrix is defined for the system consisting of the GPR antenna and the planar air-soil interface. The transmitting spectrum of the GPR antenna is expressed in terms...

  19. Design and Verification of MIMO 2x2 Reference Antennas

    DEFF Research Database (Denmark)

    Szini, Istvan Janos; Pedersen, Gert Frølund; Estrada, J.;

    2012-01-01

    The development and initial discussion of a reference MIMO 2×2 antenna concept has been presented in [1]. The reference antenna concept has been created to eliminate the uncertainties linked to the unknown antenna performance of the few LTE MIMO 2×2 reference devices or golden standards currently...

  20. Optical recoil of asymmetric nano-optical antenna.

    Science.gov (United States)

    Song, Jung-Hwan; Shin, Jonghwa; Lim, Hee-Jin; Lee, Yong-Hee

    2011-08-01

    We propose nano-optical antennas with asymmetric radiation patterns as light-driven mechanical recoil force generators. Directional antennas are found to generate recoil force efficiently when driven in the spectral proximity of their resonances. It is also shown that the recoil force is equivalent to the Poynting vector integrated over a closed sphere containing the antenna structures.

  1. Engineering Optical Antenna for Efficient Local Field Enhancement

    Science.gov (United States)

    2013-12-01

    spacing 10nm). In this dissertation, we theoretically derived the local field enhancement of the optical antenna and found that optimized radiation and...present a novel optical antenna design--the arch-dipole antenna--which has optimal radiation efficiency and small gap spacing (5 nm) fabricated by CMOS

  2. Detuning effect study of High-Q Mobile Phone Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert F.

    2015-01-01

    Number of frequency bands that have to be covered by smart phones, are ever increasing. This broadband coverage can be obtained either by using a low-Q antenna or a high-Q tunable antenna. This study investigates high-Q antennas performance when placed in proximity of the user. This study...

  3. 47 CFR 73.152 - Modification of directional antenna data.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse...

  4. 47 CFR 90.1321 - Power and antenna limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Power and antenna limits. 90.1321 Section 90... and antenna limits. (a) Base and fixed stations are limited to 25 watts/25 MHz equivalent... receiver. (2) If the transmitter employs an antenna system that emits multiple directional beams but...

  5. 47 CFR 73.685 - Transmitter location and antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB...

  6. 47 CFR 74.30 - Antenna structure, marking and lighting.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna structure, marking and lighting. 74.30... Applicable to All Services in Part 74 § 74.30 Antenna structure, marking and lighting. The provisions of part 17 of the FCC rules (Construction, Marking, and Lighting of Antenna Structures) require...

  7. A Unified Mutual Coupling Model for Multiple Antenna Systems

    Institute of Scientific and Technical Information of China (English)

    WU Yu-jiang; NIE Zai-ping

    2006-01-01

    A unified mutual coupling model for multiple antenna communication systems based on moment methods is proposed. This model combines antenna coupling and RF front-end circuit coupling, thus providing a more accurate and complete analysis of the mutual coupling effect on multiple antenna systems.

  8. 47 CFR 80.763 - Effective antenna height.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the...

  9. 47 CFR 74.1235 - Power limitations and antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Power limitations and antenna systems. 74.1235... Translator Stations and FM Broadcast Booster Stations § 74.1235 Power limitations and antenna systems. (a) An...) value determined in accordance with this paragraph. The antenna height above average terrain...

  10. 47 CFR 78.63 - Antenna structure marking and lighting.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna structure marking and lighting. 78.63... CABLE TELEVISION RELAY SERVICE General Operating Requirements § 78.63 Antenna structure marking and lighting. The owner of each antenna structure is responsible for ensuring that the structure, if...

  11. 47 CFR 73.68 - Sampling systems for antenna monitors.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Sampling systems for antenna monitors. 73.68... RADIO BROADCAST SERVICES AM Broadcast Stations § 73.68 Sampling systems for antenna monitors. (a) Each AM station permittee authorized to construct a new directional antenna system which will be...

  12. 47 CFR 73.33 - Antenna systems; showing required.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems; showing required. 73.33... RADIO BROADCAST SERVICES AM Broadcast Stations § 73.33 Antenna systems; showing required. (a) An application for authority to install a broadcast antenna shall specify a definite site and include...

  13. 47 CFR 73.45 - AM antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false AM antenna systems. 73.45 Section 73.45... Broadcast Stations § 73.45 AM antenna systems. (a) All applicants for new, additional, or different AM... existing station must specify an antenna system, the efficiency of which complies with the requirements...

  14. 47 CFR 74.22 - Use of common antenna structure.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Use of common antenna structure. 74.22 Section... Applicable to All Services in Part 74 § 74.22 Use of common antenna structure. The simultaneous use of a common antenna structure by more than one station authorized under this part, or by one or more...

  15. 47 CFR 73.150 - Directional antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Directional antenna systems. 73.150 Section 73... BROADCAST SERVICES AM Broadcast Stations § 73.150 Directional antenna systems. (a) For each station employing a directional antenna, all determinations of service provided and interference caused shall...

  16. 47 CFR 80.876 - VHF radiotelephone antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false VHF radiotelephone antenna system. 80.876... to Subpart W § 80.876 VHF radiotelephone antenna system. A vertically polarized nondirectional antenna must be provided for VHF radiotelephone installations. The construction and installation of...

  17. 47 CFR 73.54 - Antenna resistance and reactance measurements.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna resistance and reactance measurements... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.54 Antenna resistance and reactance measurements. (a) The resistance of an omnidirectional series fed antenna is measured at either the base of...

  18. 47 CFR 74.536 - Directional antenna required.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Directional antenna required. 74.536 Section 74... Auxiliary Stations § 74.536 Directional antenna required. (a) Aural broadcast STL and ICR stations are required to use a directional antenna with the minimum beamwidth necessary, consistent with...

  19. 47 CFR 5.109 - Antenna and tower requirements.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level...

  20. Mutual Coupling Between Two Identical Planar Inverted-F Antennas

    DEFF Research Database (Denmark)

    Thaysen, Jesper

    2002-01-01

    The planar inverted-F antenna (PIFA) is widely used for cellular telephones due to its compactness and size. The objective of this paper is to present the results of numerical investigations of the coupling between two equal PIFA antennas. To analyse the antenna, the method of moment computer pro...

  1. Reducing Redundancies in Reconfigurable Antenna Structures Using Graph Models

    Energy Technology Data Exchange (ETDEWEB)

    Costantine, Joseph; al-Saffar, Sinan; Christodoulou, Christos G.; Abdallah, Chaouki T.

    2010-04-23

    Many reconfigurable antennas have redundant components in their structures. In this paper we present an approach for reducing redundancies in reconfigurable antenna structures using graph models. We study reconfigurable antennas, which are grouped, categorized and modeled according to a set of proposed graph rules. Several examples are presented and discussed to demonstrate the validity of this new technique.

  2. Effects of Spatial Characteristics on Smart Antenna System with Uniform Linear Antenna Array

    Institute of Scientific and Technical Information of China (English)

    CAO Wei-feng; WANG Wen-bo

    2005-01-01

    The effect of the spatial characteristics of antenna array on smart antenna systems can not be neglected. In the paper, the relation between spatial correlation and inter-antenna distance, impinging angle, angle spread is first investigated. With the same beamforming algorithm, we simulate the performance of smart antenna system with different Angle Spread (AS) values on the conditions of ideal and real Angle of Arrival (AOA) estimation. The results show that with the ideal AOA estimation, the AOA is enough accurate to guarantee that the system only has little performance degradation even in the case of 20 degreee AS value while the real AOA estimation influenced by channel environment degrades the performance very obviously, up to about 7 dB.

  3. Near Field HF Antenna Pattern Measurement Method Using an Antenna Pattern Range

    Science.gov (United States)

    2015-12-01

    Company, Reading, MA. 2. C. Balanis. 2005. Antenna Theory Analysis and Design. John Wiley & Sons, New York, NY. 3. C. Balanis. 1989. Advanced...Engineering Electromagnetics. John Wiley & Sons, New York, NY. 4. J. Meloling and J. Allen. 2014. “A Near-to-Far Field Transformation Using Spherical...Method Using an Antenna Pattern Range Ani Saripuram Michael Daly SSC Pacific, 53560 Hull Street, San Diego, CA 92152–5001 TR 3006 SSC

  4. Antenna Near-Field Probe Station Scanner

    Science.gov (United States)

    Zaman, Afroz J. (Inventor); Lee, Richard Q. (Inventor); Darby, William G. (Inventor); Barr, Philip J. (Inventor); Lambert, Kevin M (Inventor); Miranda, Felix A. (Inventor)

    2011-01-01

    A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described.

  5. Modeling and control of antennas and telescopes

    CERN Document Server

    Gawronski, Wodek

    2008-01-01

    The book shows, step-by-step, the design, implementation, and testing of the antenna/telescope control system, from the design stage (analytical model) to fine tuning of the RF beam pointing (monopulse and conscan). It includes wide use of Matlab and Simulink..

  6. A Novel Offset Fresnel Zone Plate Antenna

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel offset Fresnel Zone Plate reflector Antenna (FZPA) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are analyzed. The comparison of this new FZPA with the circular FZPA and Mawzones FZPA is made.

  7. Adaptive optical antennas: design and evaluation

    Science.gov (United States)

    Weyrauch, Thomas; Vorontsov, Mikhail A.; Carhart, Gary W.; Simonova, Galina V.; Beresnev, Leonid A.; Polnau, Ernst E.

    2007-09-01

    We present the design and evaluation of compact adaptive optical antennas with apertures diameters of 16 mm and 100 mm for 5Gbit/s-class free-space optical communication systems. The antennas provide a bi-directional optically transparent link between fiber-optical wavelength-division multiplex systems and allow for mitigation of atmospheric-turbulence induced wavefront phase distortions with adaptive optics components. Beam steering is implemented in the antennas either with mirrors on novel tip/tilt platforms or a fiber-tip positioning system, both enabling operation bandwidths of more than 1 kHz. Bimorph piezoelectric actuated deformable mirrors are used for low-order phase-distortion compensation. An imaging system is integrated in the antennas for coarse pointing and tracking. Beam steering and wavefront control is based on blind maximization of the received signal level using a stochastic parallel gradient descent algorithm. The adaptive optics control architecture allowed the use of feedback signals provided locally within each transceiver system and remotely by the opposite transceiver system via an RF link. First atmospheric compensation results from communication experiments over a 250 m near-ground propagation path are presented.

  8. Antenna size reduction in microalgae mass culture

    NARCIS (Netherlands)

    Mooij, de T.

    2016-01-01

    The thesis describes the potential of microalgae with a reduced light harvesting antenna for biomass production under mass culture conditions (high biomass density, high light intensity). Theoretically, the lower chlorophyll content reduces the light harvesting capacity and with that the amount of p

  9. Plasma-Surface Interactions and RF Antennas

    Science.gov (United States)

    Jenkins, Thomas; Smithe, D. N.; Beckwith, K.; Davidson, B. D.; Kruger, S. E.; Pankin, A. Y.; Roark, C. M.

    2015-11-01

    Implementation of recently developed finite-difference time-domain (FDTD) modeling techniques on high-performance computing platforms allows RF power flow, and antenna near- and far-field behavior, to be studied in realistic experimental ion-cyclotron resonance heating scenarios at previously inaccessible levels of resolution. We present results and 3D animations of high-performance (10k-100k core) FDTD simulations of Alcator C-Mod's field-aligned ICRF antenna on the Titan supercomputer, considering (a) the physics of slow wave excitation in the immediate vicinity of the antenna hardware and in the scrape-off layer for various edge densities, and (b) sputtering and impurity production, as driven by self-consistent sheath potentials at antenna surfaces. Related research efforts in low-temperature plasma modeling, including the use of proper orthogonal decomposition methods for PIC/fluid modeling and the development of plasma chemistry tools (e.g. a robust and flexible reaction database, principal path reduction analysis capabilities, and improved visualization options), will also be summarized. Supported by U.S. DoE SBIR Phase I/II Award DE-SC0009501 and ALCC/OLCF.

  10. Absolute Calibration of the Lopes Antenna System

    NARCIS (Netherlands)

    Nehls, S.; Bähren, L.; Buitink, S.J.; Falcke, H.D.E.; Horneffer, K.H.A.; Kuijpers, J.M.E.; Lafebre, S.J.; Nigl, A.; Petrovic, J.

    2006-01-01

    Radio emission in extensive air showers arises from an interaction with the geomagnetic field and is subject of theoretical studies. This radio emission has advantages for the detection of high energy cosmic rays compared to secondary particle or fluorescence measurement methods. Radio antennas like

  11. Interleaved Array Antennas for FMCW Radar Applications

    NARCIS (Netherlands)

    Lager, I.E.; Trampuz, C.; Simeoni, M.; Ligthart, L.P.

    2009-01-01

    An effective and robust strategy for concurrently designing the transmit and receive antennas of a frequency-modulated, continuos-wave radar is discussed. The aperture architecture is based on the use of non-periodic, interleaved sub-arrays. Deterministic element placement is employed for ensuring d

  12. Small inductor Loaded mobile phone Antenna

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    In this paper a size reduction technique of the Planar Inverted F Antenna (PIFA) is presented. Using an 18 nH lumped inductor in addition to a small 0.3 cm3 PIFA located on a 5 mm thick dielectric foam above a 40 x 100 mm2 ground plane it is possible to reduce the resonant frequency by 33 % for a...

  13. ANTENNA-COUPLED LIGHT-MATTER INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    NOVOTNY, LUKAS

    2014-01-10

    This project is focused on antenna-coupled photon emission from single quantum emitters. The properties of optical antennas are tailored to control different photophysical parameters, such as the excited state lifetime, the saturation intensity, and the quantum yield [3]. Using a single molecule coupled to an optical antenna whose position and properties can be controllably adjusted we established a detailed and quantitative understanding of light-matter interactions in nanoscale environments. We have studied various quantum emitters: single molecules [11], quantum dots [7], rareearth ions [2], and NV centers in diamond [19]. We have systematically studied the interaction of these emitters with optical antennas. The overall objective was to establish a high-level of control over the light-matter interaction. In order to eliminate the coupling to the environment, we have taken a step further and explored the possibility of levitating the quantum emitter in high vacuum. What started as a side-project soon became a main activity in our research program and led us to the demonstration of vacuum trapping and cooling of a nanoscale particle [14].

  14. Hybrid optical antenna with high directivity gain.

    Science.gov (United States)

    Bonakdar, Alireza; Mohseni, Hooman

    2013-08-01

    Coupling of a far-field optical mode to electronic states of a quantum absorber or emitter is a crucial process in many applications, including infrared sensors, single molecule spectroscopy, and quantum metrology. In particular, achieving high quantum efficiency for a system with a deep subwavelength quantum absorber/emitter has remained desirable. In this Letter, a hybrid optical antenna based on coupling of a photonic nanojet to a metallo-dielectric antenna is proposed, which allows such efficient coupling. A quantum efficiency of about 50% is predicted for a semiconductor with volume of ~λ³/170. Despite the weak optical absorption coefficient of 2000 cm(-1) in the long infrared wavelength of ~8 μm, very strong far-field coupling has been achieved, as evidenced by an axial directivity gain of 16 dB, which is only 3 dB below of theoretical limit. Unlike the common phased array antenna, this structure does not require coherent sources to achieve a high directivity. The quantum efficiency and directivity gain are more than an order of magnitude higher than existing metallic, dielectric, or metallo-dielectric optical antenna.

  15. Stochastic Beamforming via Compact Antenna Arrays

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Pedersen, Gert Frølund

    2012-01-01

    The paper investigates the average beamforming (BF) gain of compact antenna arrays when statistical channel knowledge is available. The optimal excitation (precoding vector) and impedance termination that maximize the average BF gain are a compromise between the ones that maximize the array...

  16. Wimpy Radar Antenna! Grades 6-8.

    Science.gov (United States)

    Rushton, Erik; Ryan, Emily; Swift, Charles

    In this activity, students reinforce an antenna tower made from foam insulation so that it can withstand a 480 N-cm bending moment (torque) and a 280 N-cm twisting moment (torque) with minimal deflection. One class period is used to discuss the problem, run the initial bending and torsion tests, and graph the results. The second class is used for…

  17. Passive and active reconfigurable microstrip reflectarray antennas

    NARCIS (Netherlands)

    Hajian, M.

    2008-01-01

    Novel solutions for conceiving microstrip reflectarray antennas (MRA) using various types of patches are presented in this PhD thesis. The approach is based on the integration of a varactor diode active device into elementary hollow patch radiators. In the first part of the thesis, a new concept for

  18. Novel method for planar microstrip antenna matching impedance

    CERN Document Server

    Ali, Mahdi; Samet, Mounir

    2010-01-01

    Because all microstrip antennas have to be matched to the standard generator impedance or load, the input impedance matching method for antenna is particularly important. In this paper a new methodology in achieving matching impedance of a planar microstrip antenna for wireless application is described. The method is based on embedding an Interdigital capacitor. The fine results obtained by using a microstrip Interdigital capacitor for matching antenna impedance led to an efficient method to improve array antenna performance. In fact, a substantial saving on the whole surfaces as well as enhancement of the gain, the directivity and the power radiated was achieved.

  19. Simulation of a Broadband Antenna with the Method of Moments

    Directory of Open Access Journals (Sweden)

    M. Czarnecki

    2005-12-01

    Full Text Available In the paper selected problems of computer simulations of abroadband antenna containing large metallic surfaces with the Method ofMoments have been discussed. A novel broadband combined spiral-disconeantenna, built of a complementary spiral and a cone has been analyzed.Since the antenna contains large metallic surfaces wire-grid models hadto be developed in order to simulate the antenna with the thin-wirekernel method of moments. Several wire-grid models of the antenna havebeen proposed and analyzed. The simulation results for input impedancehave been compared to those obtained from measurements and the bestmodel of the antenna has been identified.

  20. Addressing Carrier Aggregation with Narrow-band Tunable Antennas

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert F.

    2016-01-01

    Enhancing the operating bandwidth of antennas is particularly challenging when the antenna is confined in a very restricted volume, as is the case for mobile phones. However, increasing the bandwidth provides higher data rates to the users. Consequently, the carrier aggregation technology has been...... standardized. This paper proposes an antenna design that can address the bandwidth issue of new radio frequency standards, while coping with carrier aggregation requirements. Specifically, the paper presents a dual-antenna system, where each antenna exhibits a dual resonance. The low-bands of the radio...