WorldWideScience

Sample records for antenna array synthesis

  1. Synthesis of antenna arrays radiation patterns on random geometry cylinders

    OpenAIRE

    Gabriel'yan, D. D.; Kalchenko, O. V.

    2007-01-01

    Synthesis algorithm for gain-phase radiation patterns formed by linear electrical vibrators antenna arrays located on random geometry cylinders is discussed. The results of numerical calculations are presented.

  2. Cuckoo search optimization for linear antenna arrays synthesis

    OpenAIRE

    Ahmed Haffane; Abdelhafid Hasni

    2013-01-01

    A recently developed metaheuristic optimization algorithm, the Cuckoo search algorithm, is used in this paper for the synthesis of symmetric uniformly spaced linear microstrip antennas array. Cuckoo search is based on the breeding strategy of Cuckoos augmented by a Levy flight behaviour found in the foraging habits of other species. This metaheuristic is tested on amplitude only pattern synthesis and amplitude and phase pattern synthesis. In both case, the ...

  3. Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

    Directory of Open Access Journals (Sweden)

    Alberto Reyna

    2014-01-01

    Full Text Available This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction.

  4. Vector space representation of array antenna pattern synthesis problems

    DEFF Research Database (Denmark)

    Wu, Jian; Roederer, A.G

    1991-01-01

    Considering the difficulties of the nonlinear optimization methods for the array and array fed reflector antenna power pattern synthesis problems, a novel approach has been developed to present the problem in a geographical way, which makes it possible to derive efficient algorithms and to...... visualize the optimization process. The vector space approach described provides a very powerful representation of the array pattern synthesis problems. It is not only general, since many parameters are represented under one model, but also helps to visualize the problem. The proposed approach provides a...

  5. Cِircular Antenna Array Synthesis Using Fuzzy Genetic Algorithm

    OpenAIRE

    M. Bousahla; Kadri, B; F. T. Bendimerad

    2007-01-01

    This paper presents a rigorous synthesis of circular arrays of printed antennas using a hybrid fuzzy-genetic algorithm. Fuzzy logic based controllers are applied to fine-tune dynamically the crossover and mutation probability in the genetic algorithms, in an attempt to improve the algorithm performance. The FGA approach is compared with the Standard Genetic Algorithm(SGA). Included synthesis example clearly demonstrates that while the SGA approach gives satisfactory solutions for the probl...

  6. Cuckoo search optimization for linear antenna arrays synthesis

    Directory of Open Access Journals (Sweden)

    Ahmed Haffane

    2013-01-01

    Full Text Available A recently developed metaheuristic optimization algorithm, the Cuckoo search algorithm, is used in this paper for the synthesis of symmetric uniformly spaced linear microstrip antennas array. Cuckoo search is based on the breeding strategy of Cuckoos augmented by a Levy flight behaviour found in the foraging habits of other species. This metaheuristic is tested on amplitude only pattern synthesis and amplitude and phase pattern synthesis. In both case, the objective, is to determinate the optimal excitations element that produce a synthesized radiation pattern within given bounds specified by a pattern mask.

  7. Concentric Circular Antenna Array Synthesis Using Biogeography Based Optimization

    Directory of Open Access Journals (Sweden)

    Urvinder Singh

    2012-03-01

    Full Text Available Biogeography based optimization (BBO is a new stochastic force based on the science of biogeography. Biogeography is the schoolwork of geographical allotment of biological organisms. BBO utilizes migration operator to share information between the problem solutions. The problem solutions are known as habitats and sharing of features is called migration. In this paper, BBO algorithm is developed to optimize the current excitations of concentric circular antenna arrays (CCAA. Concentric Circular Antenna Array (CCAA has numerous attractive features that make it essential in mobile and communication applications. The goal of the optimization is to reduce the side lobe levels and the primary lobe beam width as much as possible. To confirm the capabilities of BBO, three different CCAA antennas of different sizes are taken. The results obtained by BBO are compared with the Real coded Genetic Algorithm (RGA, Craziness based Particle Swarm Optimization (CRPSO and Hybrid Evolutionary Programming (HEP.

  8. Pattern Synthesis of Dual-band Shared Aperture Interleaved Linear Antenna Arrays

    Directory of Open Access Journals (Sweden)

    H. Guo

    2014-09-01

    Full Text Available This paper presents an approach to improve the efficiency of an array aperture by interleaving two different arrays in the same aperture area. Two sub-arrays working at different frequencies are interleaved in the same linear aperture area. The available aperture area is efficiently used. The element positions of antenna array are optimized by using Invasive Weed Optimization (IWO to reduce the peak side lobe level (PSLL of the radiation pattern. To overcome the shortness of traditional methods which can only fulfill the design of shared aperture antenna array working at the same frequency, this method can achieve the design of dual-band antenna array with wide working frequency range. Simulation results show that the proposed method is feasible and efficient in the synthesis of dual-band shared aperture antenna array.

  9. Asymmetric Shaped-Pattern Synthesis for Planar Antenna Arrays

    Directory of Open Access Journals (Sweden)

    T. M. Bruintjes

    2016-01-01

    Full Text Available A procedure to synthesize asymmetrically shaped beam patterns is developed for planar antenna arrays. As it is based on the quasi-analytical method of collapsed distributions, the main advantage of this procedure is the ability to realize a shaped (null-free region with very low ripple. Smooth and asymmetrically shaped regions can be used for Direction-of-Arrival estimation and subsequently for efficient tracking with a single output (fully analog beamformer.

  10. PHASE-ONLY ADAPTIVE NULLING WITH TAGUCHI’S METHOD FOR ANTENNA ARRAY SYNTHESIS

    Directory of Open Access Journals (Sweden)

    Amor Smida

    2012-01-01

    Full Text Available A new and very speedy synthesis method for linear array antennas with periodic element spacing is described. This study presents an efficient method for the pattern synthesis based on Taguchi’s method. A number of representative examples are presented to demonstrate the various unique capabilities of the method. A set of phase shift weights are generated in order to steer the beam towards any desired direction and avoiding interference. For isotropic linear antenna arrays parameter. The fitness function that allows the calculations of the phase shift weights is presented. The results of Taguchi’s method are validated by using rectangular patch antenna and simulated by software CST2009 (CST microwave studio. Taguchi’s method is briefly described in part 2. In part 3 the formulation of the array factor for linear arrays is given and fitness function will be mentioned. The numerical results optimized by Taguchi’s method are given in part 4. The last results are discuss and validated by using rectangular patch antenna and simulated by software CST2009 (CST microwave studio in part 5. Finally, part 6 makes conclusions.

  11. Design and synthesis of flexible switching 1 × 2 antenna array on Kapton substrate

    Science.gov (United States)

    Georges Rabobason, Yvon; Rigas, Grigorios; Swaisaenyakorn, Srijittar; Mirkhaydarov, Bobur; Ravelo, Blaise; Shkunov, Maxim; Young, Paul; Benjelloun, Nabil

    2016-06-01

    Flexible front- and back-end RF/analogue system antennas were recently emerged. However, little flexible antenna system design is available so far, in planar hybrid technology with surface mounted components. This paper describes the design feasibility of flexible switching 1 × 2 antenna array system. It acts as a switching antenna implemented in hexapole configuration. The system is comprised of a key element RF switch terminated by two identical patch antennas associated to half-wave elementary transmission lines (TLs). A detailed theory illustrating the global S-parameter model determination in function of the given RF-switch return and insertion losses is established. In difference to the conventional microwave circuit theory, the proposed equivalent S-parameter model is originally built with the non-standard optimized antenna load. Thus, the synthesis method of the terminal antenna input impedance and the output access line characteristic impedance is formulated in function of the specified return and optimal transmission losses. The design method and theoretical approach feasibility is verified with the demonstrator of flexible switching 1 × 2 antenna array printed on Kapton substrate. The circuit prototype is implemented in hybrid planar technology integrating patch antenna operating at about 6 GHz and a packaged GaAs RF switch associated to the RF/DC signal decoupling accessory mounted surface components. Simulations of the designed circuit transmission and isolation losses from 5.5 GHz to 7 GHz were carried out by using the commercial RF switch S-parameter touchstone model provided by the manufacturer. The simulated and measured return losses are compared and discussed. Then, the measured radiation patterns confirm the proposed switched antenna concept feasibility.

  12. SYNTHESIS OF DUAL RADIATION PATTERN OF RECTANGULAR PLANAR ARRAY ANTENNA USING EVOLUTIONARY ALGORITHM

    Directory of Open Access Journals (Sweden)

    Debasis Mandal

    2015-09-01

    Full Text Available A pattern synthesis method based on Evolutionary Algorithm is presented to generate a dual radiation pattern from a planar array of isotropic antennas. The desired patterns are obtained by finding out optimum set of elements excitations. Flat-top and Pencil beams share a common optimum amplitude distribution among the array elements. Flat-top beam is generated by updating the zero phases with the optimum phases among the elements. 4 bit discrete amplitudes and 5 bit discrete phases have been taken to simplify the design of the feed network. Results clearly show the effectiveness of the proposed method.

  13. Analysis of Robustness for Convex Optimization Applied to Array Antenna Pattern Synthesis

    Directory of Open Access Journals (Sweden)

    R. Torrealba

    2008-01-01

    Full Text Available This study presents an analysis of the convex optimization applied to the synthesis of the radiation pattern for linear antenna arrays. This study emphasizes the application of the convex optimization for the array pattern synthesis considering the simultaneous elimination of several zones interferences, reduction of the level of power in two space zones densely populated by interferences, as well as the variation of these zones in terms of proximity-distance of the source of interest, variation of the size of the interferences zones and the number of zones within the radiation pattern. Simulation results are provided. These results define certain levels where the linear array could be exploited to achieve a maximum performance.

  14. Bee swarm algorithm for synthesis of antenna arrays

    OpenAIRE

    Galan, A. Yu.; Sauleau, R.

    2009-01-01

    Paper describes basics of a particle swarm optimization (PSO) algorithm and presents results of a comparative study of its performance when applied with different boundary conditions. Approbation of the algorithm is done on a set of test functions and on a classical test problem of a linear array phase taper aimed at the side-lobe level suppression.

  15. Bee swarm algorithm for synthesis of antenna arrays

    OpenAIRE

    Galan, A. Yu.; Sauleau, R.; Nosich, A. I.; Boriskin, Artem V.

    2009-01-01

    Article describes basics of a particle swarm optimization (PSO) algorithm and presents results of a comparative study of its performance when applied with different boundary conditions. Approbation of the algorithm is done on a set of test functions and on a classical test problem of a linear array phase taper aimed at the side-lobe level suppression.

  16. Algorithm for the synthesis of linear antenna arrays with desired radiation pattern and integral amplitude coefficients

    Directory of Open Access Journals (Sweden)

    Sadchenko A. V.

    2015-06-01

    Full Text Available Ahe problem of technical implementation of phased array antennas (PAR with the required radiation pattern (RP is the complexity of the construction of the beamforming device that consists of a set of controlled attenuators and phase shifters. It is possible to simplify the technical implementation of PAR, if complex representation of coefficients of amplitude-phase distribution of the field along the lattice is approximated by real values in the synthesis stage. It is known that the amplitude distribution of the field in the aperture of the antenna array and the radiation pattern are associated with Fourier transform. Thus, the amplitude and phase coefficients are first calculated using the Fourier transform, and then processed according to the selected type of circuit realization of attenuators and phase shifters. The calculation of the inverse Fourier transform of the modified coefficients allows calculating the synthesized orientation function. This study aims to develop a search algorithm for amplitude and phase coefficients, taking into account the fact that integer-valued amplitudes and phases are technically easier to implement than real ones. Synthesis algorithm for equidistant linear array with a half-wavelength irradiators pitch (&l;/2 is as follows. From a given directivity function the discrete Fourier transform (DFT in the form of an array of complex numbers is found, the resulting array is then transformed into a set of attenuations for attenuators and phase shifts for phase shifters, while the amplitude coefficients are rounded off to integers, and phases are binarizated (0, ?. The practical value of this algorithm is particularly high when using controlled phase shifters and attenuators integrally. The work confirms the possibility of a thermoelectric converter of human body application for an electronic medical thermometer power supply.

  17. Phase-Only Planar Antenna Array Synthesis with Fuzzy Genetic Algorithms

    CERN Document Server

    Kadri, Boufeldja; Bendimerad, Fethi Tarik

    2010-01-01

    This paper describes a new method for the synthesis of planar antenna arrays using fuzzy genetic algorithms (FGAs) by optimizing phase excitation coefficients to best meet a desired radiation pattern. We present the application of a rigorous optimization technique based on fuzzy genetic algorithms (FGAs), the optimizing algorithm is obtained by adjusting control parameters of a standard version of genetic algorithm (SGAs) using a fuzzy controller (FLC) depending on the best individual fitness and the population diversity measurements (PDM). The presented optimization algorithms were previously checked on specific mathematical test function and show their superior capabilities with respect to the standard version (SGAs). A planar array with rectangular cells using a probe feed is considered. Included example using FGA demonstrates the good agreement between the desired and calculated radiation patterns than those obtained by a SGA.

  18. Atacama Compact Array Antennas

    OpenAIRE

    Saito, Masao; Inatani, Junji; 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...

  19. Imaging antenna arrays

    Science.gov (United States)

    Rutledge, D. B.; Muha, M. S.

    1982-01-01

    Many millimeter and far-infrared imaging systems are limited in sensitivity and speed because they depend on a single scanned element. Because of recent advances in planar detectors such as Schottky diodes, superconducting tunnel junctions, and microbolometers, an attractive approach to this problem is a planar antenna array with integrated detectors. A planar line antenna array and optical system for imaging has been developed. The significant advances are a 'reverse-microscope' optical configuration and a modified bow-tie antenna design. In the 'reverse-microscope' configuration, a lens is attached to the bottom of the substrate containing the antennas. Imaging is done through the substrate. This configuration eliminates the troublesome effects of substrate surface waves. The substrate lens has only a single refracting surface, making possible a virtually aplanatic system, with little spherical aberration or coma. The array is characterized by an optical transfer function that is easily measured. An array with 19 dB crosstalk levels between adjacent antennas has been tested and it was found that the array captured 50 percent of the available power. This imaging system was diffraction limited.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. Pattern Synthesis of Planar Nonuniform Circular Antenna Arrays Using a Chaotic Adaptive Invasive Weed Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Huaning Wu

    2014-01-01

    Full Text Available A novel invasive weed optimization (IWO variant called chaotic adaptive invasive weed optimization (CAIWO is proposed and applied for the optimization of nonuniform circular antenna arrays. A chaotic search method has been combined into the modified IWO with adaptive dispersion, where the seeds produced by a weed are dispersed in the search space with standard deviation specified by the fitness value of the weed. To evaluate the performance of CAIWO, several representative benchmark functions are minimized using various optimization algorithms. Numerical results demonstrate that the proposed approach improves the performance of the algorithm significantly, in terms of both the convergence speed and exploration ability. Moreover, the scheme of CAIWO is employed to find out an optimal set of weights and antenna element separation to obtain a radiation pattern with maximum side-lobe level (SLL reduction with different numbers of antenna element under two cases with different purposes. The design results obtained by CAIWO have comfortably outperformed the published results obtained by other state-of-the-art metaheuristics in a statistically meaningful way.

  5. Vector synthesis problem of random geometry antenna differentiation conditions

    OpenAIRE

    Mishchenko, S. E.

    2007-01-01

    The problem definition of general random geometry continuous and discontinuous antenna vector synthesis is discussed. Conditions are formulated which allow presenting the initial antenna vector synthesis problem in the form of array of some scalar synthesis problems while locating the antenna in the free space and near the surface. On plane, cylinder and sphere examples antenna synthesis problems division possibilities of scalar problems are examined.

  6. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2001-01-01

    This book gives an introduction to the possibilities of radar technology based on active array antennas, giving examples of modern practical systems. There are many valuable lessons presented for designers of future high standard multifunction radar systems for military and civil applications. The book will appeal to graduate level engineers, researchers, and managers in the field of radar, aviation and space technology.

  7. 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 ...

  8. Antenna Arrays for Tactical Communication Systems: A Comparative Study

    Directory of Open Access Journals (Sweden)

    L. Slama

    2011-12-01

    Full Text Available In this paper, we give a comparative study of several planar antenna concepts for reliable long range links in a tactical environment. The antenna elements are studied in terms of their electrical properties (bandwidth, reflection coefficient and radiation characteristics and construction (robustness and material consumption. First, we model single antenna elements to investigate if they meet the requirements. Second, we arrange the elements with the best features into 2x2 arrays. Computer simulations of the arrays are verified by measurements. Finally, we formulate recommendations for large array (8x8 or 16x16 elements synthesis to achieve the required properties.

  9. Broadband antenna arrays using planar horns

    OpenAIRE

    Braude, V. B.; Sukhovetskaya, S. B.

    1997-01-01

    Broadband antennas are vitally important for various applications ranging from TV broadcasting to carrier-free ground-probing radars. We propose a microwave broadband antenna array (BAA), which may be realised using microstrip planar horns — flared end-fire radiating slot lines, known as Vivaldi-type antennas.

  10. 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...

  11. Far-infrared imaging antenna arrays

    OpenAIRE

    Neikirk, Dean P.; Rutledge, David B.; Muha, Michael S.; Park, Hyeon; Yu, Chang-Xuan

    1982-01-01

    A far-infrared imaging antenna array has been demonstrated for the first time. The array is a line of evaporated silver bow-tie antennas on a fused-quartz substrate with bismuth-microbolometer detectors. The measured optical transfer function shows that the system is diffraction limited. This imaging array should find direct application in fusion plasma diagnostics. If the microbolometers can be replaced by more sensitive diode detectors, the array should also find application in radiometry a...

  12. Broadband Multilayered Array Antenna with EBG Reflector

    Directory of Open Access Journals (Sweden)

    P. Chen

    2013-01-01

    Full Text Available Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure. The impedance bandwidth is broadened, but meanwhile, the sidelobe of the directivity pattern and backlobe level are enlarged. A broadband stacked slot coupling microstrip antenna array with EBG structure reflector is proposed. Test results indicate that the proposed reflector structure can effectively improve the directivity pattern of stacked antenna and aperture coupled antenna, promote the front-to-back ratio, and reduce the thickness of the antenna. Therefore, it is more suitable to be applied as an airborne antenna.

  13. A SIW Antipodal Vivaldi Array Antenna Design

    OpenAIRE

    Ying Suo; Wei Li; Jianzhong Chen

    2016-01-01

    A kind of compact SIW (substrate integrated waveguide) Vivaldi array antenna is proposed and analyzed. The antenna consisted of 4 Vivaldi structure radiation elements fed by an equal power divider with SIW technology. The radiation element is composed of antipodal index gradient microstrip lines on both sides of the substrate. The measured reflection coefficient of the array antenna is less than −10 dB from 8.88 GHz to 10.02 GHz. The measured gain of the array antenna is 13.3 dB on 9.5 GHz....

  14. 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.

  15. Numerical analysis of patch antenna as antenna array element

    OpenAIRE

    Kizimenko, V.; Bobkov, Y

    2009-01-01

    The patch antennas as antenna array element can be modeling by finite element method (programs Microwave Office, Ansoft HFSS and other). But this method need to use fast computer with memory large size. In this work the authors make an attempt to use thin wire integral equation method for patch antenna analysis. The results of modeling by proposed method are compared with the same of modeling by finite elements method and experimental results.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. Imaging antenna array at 119 µm

    OpenAIRE

    Neikirk, Dean P.; Tong, Peter P.; Rutledge, David B.; Park, Hyeon; Young, Peter E.

    1982-01-01

    A focal-plane imaging antenna array has been demonstrated at 119 µm. The array is a line of evaporated silver bow-tie antennas with bismuth microbolometer detectors on a silicon substrate. Radiation is coupled into the array by a lens placed on the back of the substrate. The bolometers are thermally isolated from the silicon substrate with a half-micron layer of polyimide. The array performance is demonstrated by coherent imaging of a series of holes at half the diffraction-limited cut-off fr...

  1. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  2. Phased array antennas with optimized element patterns

    CERN Document Server

    Skobelev, Sergei P

    2011-01-01

    This authoritative resource provides you with a detailed description of ideal array element characteristics that help you estimate the quality of development of real-world phased array antennas. You find several approaches to optimum phased array design, allowing you to provide specified array gain in a specific region of scan, using a minimum number of expensive, controlled devices. Moreover, this practical book presents important numerical methods that you can use to model and optimize phased array structure to obtain the best array characteristics that the chosen structure can provide.From

  3. Far-infrared imaging antenna arrays

    Science.gov (United States)

    Neikirk, D. P.; Rutledge, D. B.; Muha, M. S.; Park, H.; Yu, C.-X.

    1982-01-01

    A far-infrared monolithic imaging antenna array with diffraction-limited resolution has been demonstrated. The optical system is similar to an oil-immersion microscope, except that the position of the object and the image are interchanged. The array is a series of evaporated silver bow-tie antennas of 75 nm thick, spaced at 310 microns, on a fused-quartz substrate; the bow angle of 60 deg gives an impedance of 150 ohm to match to bismuth microbolometers. The measured responsivity of the array elements is 1-2 V/W at the relatively low bias of 1 mA. Previous measurements have shown that the bolometers are 1/f noise limited up to 100 kHz and that they have a frequency response of 5 MHz. The antenna array should be adequate for far-infrared plasma interferometer measurements.

  4. The modelling of plane curvilinear dipole antenna arrays

    OpenAIRE

    Hoblyk, Viktor V.; Liske, O. M.; Yakovenko, Eugenia I.

    2005-01-01

    In this work the results of mathematical model design for printed dipole antenna arrays are presented. The arrays are feeding by curvilinear  transmission slotline. The investigation is important for the antenna arrays theory and useful for the design of antenna arrays with improved characteristics.

  5. A Flexible Phased-MIMO Array Antenna with Transmit Beamforming

    OpenAIRE

    Wen-Qin Wang; Huaizong Shao

    2012-01-01

    Although phased-array antennas have been widely employed in modern radars, the requirements of many emerging applications call for new more advanced array antennas. This paper proposes a flexible phased-array multiple-input multiple-output (MIMO) array antenna with transmit beamforming. This approach divides the transmit antenna array into multiple subarrays that are allowed to overlap each subarray coherently transmits a distinct waveform, which is orthogonal to the waveforms transmitted by ...

  6. 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

  7. Deployable Wide-Aperture Array Antennas

    Science.gov (United States)

    Fink, Patrick W.; Dobbins, Justin A.; Lin, Greg Y.; Chu, Andrew; Scully, Robert C.

    2005-01-01

    Inexpensive, lightweight array antennas on flexible substrates are under development to satisfy a need for large-aperture antennas that can be stored compactly during transport and deployed to full size in the field. Conceived for use aboard spacecraft, antennas of this type also have potential terrestrial uses . most likely, as means to extend the ranges of cellular telephones in rural settings. Several simple deployment mechanisms are envisioned. One example is shown in the figure, where the deployment mechanism, a springlike material contained in a sleeve around the perimeter of a flexible membrane, is based on a common automobile window shade. The array can be formed of antenna elements that are printed on small sections of semi-flexible laminates, or preferably, elements that are constructed of conducting fabric. Likewise, a distribution network connecting the elements can be created from conventional technologies such as lightweight, flexible coaxial cable and a surface mount power divider, or preferably, from elements formed from conductive fabrics. Conventional technologies may be stitched onto a supporting flexible membrane or contained within pockets that are stitched onto a flexible membrane. Components created from conductive fabrics may be attached by stitching conductive strips to a nonconductive membrane, embroidering conductive threads into a nonconductive membrane, or weaving predetermined patterns directly into the membrane. The deployable antenna may comprise multiple types of antenna elements. For example, thin profile antenna elements above a ground plane, both attached to the supporting flexible membrane, can be used to create a unidirectional boresight radiation pattern. Or, antenna elements without a ground plane, such as bow-tie dipoles, can be attached to the membrane to create a bidirectional array such as that shown in the figure. For either type of antenna element, the dual configuration, i.e., elements formed of slots in a conductive

  8. Range-Angle-Dependent Beamforming by Frequency Diverse Array Antenna

    OpenAIRE

    Wen-Qin Wang; Huaizong Shao; Jingye Cai

    2012-01-01

    This paper proposes a range-angle-dependent beamforming for frequency diverse array (FDA) antenna systems. Unlike conventional phased-array antenna, the FDA antenna employs a small amount of frequency increment compared to the carrier frequency across the array elements. The use of frequency increment generates an antenna pattern that is a function of range, time and angle. The range-angle-dependent beamforming allows the FDA antenna to transmit energy over a desired range or angle. This prov...

  9. Biologically-inspired, electrically small antenna arrays

    Science.gov (United States)

    Masoumi, Amir Reza

    First, the motivation behind adding a passive external coupling network after antenna arrays is discussed, the concept of biomimetic antenna arrays (BMAAs) introduced and some of the previous work done in this area have been reviewed. Next, a BMAA which achieves an angular resolution of roughly 15 times its regular counterpart is introduced and fully characterized. The introduced BMAA employs transformers which considerably degrade its performance, namely its output power. To cicumvent this shortcoming a new architecture of a BMAA that does not employ transformers and therefore yields a higher output power for the same angular resolution has been subsequently presented. Moreover, a detailed noise analysis of this BMAA is carried out and the output noise of the new architecture is compared with the output noise of the original design. The modified twoelement BMAA architecture is then extended to multiple elements. A novel nonlinear optimization process is introduced that maximizes the total power captured by the BMAA for a given angular resolution and the concept illustrated for a three-element antenna array. Next an optimum two-element BMAA which achieves the maximum possible angular resolution while obtaining the same output power level of a regular antenna array with the same elements and spacing is introduced. A novel two-element superdirective array based on this optimum BMAA has been also discussed. The passive BMAAs discussed in this thesis have a relatively narrow bandwidth. To extend the bandwidth of BMAAs, non- Foster networks have been employed in their external coupling networks and it has been demonstrated that they can increase their bandwidth by a factor of roughly 33. Finally, the BMAA concept has been extended to nano-antenna arrays and a concept for designing sub-wavelength angle-sensing detectors at optical wavelengths has been introduced.

  10. 天线上行组阵空间功率合成性能初步分析%Preliminary analysis of spatial power synthesis performance in antenna uplink array

    Institute of Scientific and Technical Information of China (English)

    郭劲松; 洪家财

    2015-01-01

    Antenna uplink array is one of the important applications of spatial power synthesis technology,which can im-prove the effective isotropic radiated power (EIRP) value of the far-field antenna greatly. The spatial power synthesis perfor-mance in the uplink array is conducted with theoretical analysis and simulation verification emphatically. The basic concepts, methods and principles,and the main advantages of the spatial power synthesis are introduced,then the theory of spatial power synthesis in the uplink array is deduced with formula,and analyzed briefly from the perspective of the antenna far-field pattern. The spatial power synthesis performance in the uplink array was simulated by Matlab software. The adjustment of the synthetic power was realized by changing the number of array element or adjusting the phase difference among antennas,and observing the changes of interference fringes. The simulation results prove that the feasibility of spatial power synthesis can be achieved by antenna uplink array in theory.%天线上行组阵是空间功率合成技术中的重要应用之一,将极大提高天线远场EIRP值.重点对上行组阵中空间功率合成的性能进行理论分析和仿真验证.首先介绍了空间功率合成的基本概念、方法原理、主要优点;然后对天线上行组阵空间功率合成的理论进行了公式推导,并从天线远场方向图的角度进行了简要分析;最后通过Matlab软件对天线上行组阵空间功率合成性能进行了仿真,通过改变阵元个数或者调整天线间相位差,观察干涉条纹变化,可实现合成功率改变.仿真在理论上验证了天线上行组阵实现空间功率合成的可行性.

  11. Terahertz Array Receivers with Integrated Antennas

    Science.gov (United States)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; Thomas, Bertrand; Mehdi, Imran

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  12. Designing Antenna Arrays Using Signal Processing, Image Processing and Optimization Toolboxes of MATLAB

    OpenAIRE

    Joseph, Sahaya Kulandai Raj; Schoebel, Joerg

    2010-01-01

    Exploiting the similarity between signal-processing theory and antenna-array theory, it has been demonstrated that with little effort analysis of antenna arrays can be done using signaland image-processing tools of MATLAB. The analogy between FIR filters and arrays can be effectively used to explain the concepts of the arrays to students. Also, synthesis of arrays, to a first approximation, can be carried out using signal-processing tools in the case of onedimensional arrays, and image-proc...

  13. Utilization of antenna arrays in HF systems

    Directory of Open Access Journals (Sweden)

    Louis Bertel

    2009-06-01

    Full Text Available

    Different applications of radio systems are based on the implementation of antenna arrays. Classically, radio direction

    finding operates with a multi channel receiving system connected to an array of receiving antennas. More

    recently, MIMO architectures have been proposed to increase the capacity of radio links by the use of antenna

    arrays at both the transmitter and receiver.

    The first part of this paper describes some novel experimental work carried out to examine the feasibility of applying

    MIMO techniques for communications within the HF radio band. A detailed correlation analysis of a variety

    of different antenna array configurations is presented. The second section of the paper also deals with HF

    MIMO communications, focusing on the problem from a modelling point of view. The third part presents a sensitivity

    analysis of different antenna array structures for HF direction finding applications. The results demonstrate

    that when modelling errors, heterogeneous antenna arrays are more robust in comparison to homogeneous structures


  14. A Two Element Plasma Antenna Array

    Directory of Open Access Journals (Sweden)

    F. Sadeghikia

    2013-10-01

    Full Text Available This theoretical study presents the characteristics of plasma monopole antennas in the VHF/UHF range using finite difference time domain (FDTD simulation. Results show that more broadband characteristics can be obtained by increasing the diameter of the plasma tube and that the minor lobes diminish in intensity as diameter increases. Furthermore, the nulls are replaced by low level radiation. Since the collision frequency, which is a function of gas pressure, represents the loss mechanism of plasma, decreasing its value increases the gain and radar cross section (RCS of the antenna. Theoretical modeling shows that at higher plasma frequencies with respect to the signal frequency, the gain and radar cross section of the plasma antenna are high enough and that the impedance curves are altered as the plasma frequency varies. Using these preliminary studies, mutual impedance and gain of a broadside array of two parallel side-by-side plasma elements is presented.

  15. Utilization of antenna arrays in HF systems.

    OpenAIRE

    Louis Bertel; Nasir M. Abbasi; Stuart M. Feeney; Sana Salous; Yvon Erhel; Hal J. Strangeways; E. Michael Warrington; Salil D. Gunashekar; Dominique Lemur; François Marie; Martial Oger

    2009-01-01

    Different applications of radio systems are based on the implementation of antenna arrays. Classically, radio direction

    finding operates with a multi channel receiving system connected to an array of receiving antennas. More

    recently, MIMO architectures have been propos...

  16. Spatially resolving antenna arrays using frequency diversity.

    Science.gov (United States)

    Marks, Daniel L; Gollub, Jonah; Smith, David R

    2016-05-01

    Radio imaging devices and synthetic aperture radar typically use either mechanical scanning or phased arrays to illuminate a target with spatially varying radiation patterns. Mechanical scanning is unsuitable for many high-speed imaging applications, and phased arrays contain many active components and are technologically and cost prohibitive at millimeter and terahertz frequencies. We show that antennas deliberately designed to produce many different radiation patterns as the frequency is varied can reduce the number of active components necessary while still capturing high-quality images. This approach, called frequency-diversity imaging, can capture an entire two-dimensional image using only a single transmit and receive antenna with broadband illumination. We provide simple principles that ascertain whether a design is likely to achieve particular resolution specifications, and illustrate these principles with simulations. PMID:27140887

  17. Analysis of electrical performances of planar active phased array antennas with distorted array plane

    Institute of Scientific and Technical Information of China (English)

    Wang Congsi; Bao Hong; Zhang Fushun; Feng Xingang

    2009-01-01

    a planar phased array antenna with different distortions grades prove the validity of the model.Therefore,by the method,the antenna designers may set the reasonable requirement on the structural tolerance in manufacturing antenna.

  18. Microstrip Antenna Arrays on Multilayer LCP Substrates

    Science.gov (United States)

    Thompson, Dane; Bairavasubramanian, Ramanan; Wang, Guoan; Kingsley, Nickolas D.; Papapolymerou, Ioannis; Tenteris, Emmanouil M.; DeJean, Gerald; Li, RonglLin

    2007-01-01

    A research and development effort now underway is directed toward satisfying requirements for a new type of relatively inexpensive, lightweight, microwave antenna array and associated circuitry packaged in a thin, flexible sheet that can readily be mounted on a curved or flat rigid or semi-rigid surface. A representative package of this type consists of microwave antenna circuitry embedded in and/or on a multilayer liquid- crystal polymer (LCP) substrate. The circuitry typically includes an array of printed metal microstrip patch antenna elements and their feedlines on one or more of the LCP layer(s). The circuitry can also include such components as electrostatically actuated microelectromechanical systems (MEMS) switches for connecting and disconnecting antenna elements and feedlines. In addition, the circuitry can include switchable phase shifters described below. LCPs were chosen over other flexible substrate materials because they have properties that are especially attractive for high-performance microwave applications. These properties include low permittivity, low loss tangent, low water-absorption coefficient, and low cost. By means of heat treatments, their coefficients of thermal expansion can be tailored to make them more amenable to integration into packages that include other materials. The nature of the flexibility of LCPs is such that large LCP sheets containing antenna arrays can be rolled up, then later easily unrolled and deployed. Figure 1 depicts a prototype three- LCP-layer package containing two four-element, dual-polarization microstrip-patch arrays: one for a frequency of 14 GHz, the other for a frequency of 35 GHz. The 35-GHz patches are embedded on top surface of the middle [15-mil (approx.0.13-mm)-thick] LCP layer; the 14- GHz patches are placed on the top surface of the upper [9-mil (approx. 0.23-mm)-thick] LCP layer. The particular choice of LCP layer thicknesses was made on the basis of extensive analysis of the effects of the

  19. Two-Dimensional Time-Domain Antenna Arrays for Optimum Steerable Energy Pattern with Low Side Lobes

    Directory of Open Access Journals (Sweden)

    Alberto Reyna

    2014-01-01

    Full Text Available This document presents the synthesis of different two-dimensional time-domain antenna arrays for steerable energy patterns with side lobe levels. The research is focused on the uniform and nonuniform distributions of true-time exciting delays and positions of antenna elements. The uniform square array, random array, uniform concentric ring array, and rotated nonuniform concentric ring array geometries are particularly studied. These geometries are synthesized by using the well-known sequential quadratic programming. The synthesis regards the optimal true-time exciting delays and optimal positions of pulsed antenna elements. The results show the capabilities of the different antenna arrays to steer the beam in their energy pattern in time domain and how their performance is in frequency domain after the synthesis in time domain.

  20. A novel array antenna for MSAT applications

    Science.gov (United States)

    Bodnar, Donald G.; Rainer, B. Keith; Rahmat-Samii, Yahya

    1989-01-01

    The issue of reducing the cost of phased array vehicle antennas through the use of a lens feeding arrangement instead of phase shifters at each element is addressed. In particular, the economic viability of a mobile satellite system (MSAT) is largely dependent on the efficient use of the allocated scarce spectrum and orbit as well as the satellite power. the type of vehicle antenna used will play a critical role in achieving this efficiency. A standard design approach for an electronically steered array uses phase shifters at each element to provide beam steering. A method for reducing the required number of phase shifters by using an R-KR lens feed network is outlined. The authors briefly discuss the phase shifter approach to beam steering, examine various lens feed techniques, and describe the R-KR lens approach. The lens feed network architecture is examined, a computer model for simulation of the array is presented, and the results of analysis of a suggested design for the MSAT application are given. In addition, satellite acquisition and tracking considerations are investigated.

  1. The Submillimeter Array Antennas and Receivers

    CERN Document Server

    Blundell, R

    2005-01-01

    The Submillimeter Array (SMA) was conceived at the Smithsonian Astrophysical Observatory in 1984 as a six element interferometer to operate in the major atmospheric windows from about 200 to 900 GHz. In 1996, the Academica Sinica Institute of Astronomy and Astrophysics of Taiwan joined the project and agreed to provide additional hardware to expand the interferometer to eight elements. All eight antennas are now operating at the observatory site on Mauna Kea, and astronomical observations have been made in the 230, 345, and 650 GHz bands. The SMA antennas have a diameter of 6 m, a surface accuracy of better than 25 micron rms, and can be reconfigured to provide spatial resolutions down to about 0.5" at 200 GHz and, eventually, 0.1" at 850 GHz. Coupling to the receiver package within each antenna is achieved via a beam waveguide, in a bent Nasmyth configuration, comprised of a flat tertiary mirror and two ellipsoidal mirrors that form a secondary pupil used for receiver calibration. An additional fixed mirror ...

  2. Integration of Antenna Array with Multicrystalline Silicon Solar Cell

    OpenAIRE

    O'Conchubhair, Oisin; McEvoy, Patrick; Ammann, Max

    2015-01-01

    The integration of a low-profile antenna array with a multicrystalline silicon solar cell capable of powering a low-power wireless sensor at 2.45 GHz is reported. Lattice bus bars on the cell are exploited to minimize antenna shadows from low-profile antennas and transmission lines for a higher output power. The dual inverted-F array improves gain, and beam switching enables the array to sweep a wider coverage angle with larger beamwidths compared to other solar integrated antennas.

  3. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    Science.gov (United States)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  4. Using Antenna Arrays to Motivate the Study of Sinusoids

    Science.gov (United States)

    Becker, J. P.

    2010-01-01

    Educational activities involving antenna arrays to motivate the study of sinusoids are described. Specifically, using fundamental concepts related to phase and simple geometric arguments, students are asked to predict the location of interference nulls in the radiation pattern of two-element phased array antennas. The location of the radiation…

  5. Thinning of elliptical and concentric elliptical antenna arrays using particle swarm optimization

    OpenAIRE

    Rajesh Bera; Jibendu Sekhar Roy

    2013-01-01

    Design of thinned elliptical antenna arrays ofuniformly excited isotropic antennas using particle swarmoptimization (PSO), is reported. Thinned arrays can generatedirective beam with minimum side lobe level (SLL) withoutdegrading the performance of fully populated antenna arrayssignificantly. Thinning of elliptical antenna arrays using PSO areoptimized with different values of eccentricity and variation ofside lobe level with eccentricity of thinned antenna array isreported. Using optimizatio...

  6. State-of-the-art and trends of Ground-Penetrating Radar antenna arrays

    Science.gov (United States)

    Vescovo, Roberto; Pajewski, Lara; Tosti, Fabio

    2016-04-01

    The aim of this contribution is to offer an overview on the antenna arrays for GPR systems, current trends and open issues. Antennas are a critical hardware component of a radar system, dictating its performance in terms of capability to detect targets. Nevertheless, most of the research efforts in the Ground-Penetrating Radar (GPR) area focus on the use of this imaging technique in a plethora of different applications and on the improvement of modelling/inversion/processing techniques, whereas a limited number of studies deal with technological issues related to the design of novel systems, including the synthesis, optimisation and characterisation of advanced antennas. Even fewer are the research activities carried out to develop innovative antenna arrays. GPR antennas operate in a strongly demanding environment and should satisfy a number of requirements, somehow unique and very different than those of conventional radar antennas. The same applies to GPR antenna arrays. The first requirement is an ultra-wide frequency band: the radar has to transmit and receive short-duration time-domain waveforms, in the order of a few nanoseconds, the time-duration of the emitted pulses being a trade-off between the desired radar resolution and penetration depth. Furthermore, GPR antennas should have a linear phase characteristic over the whole operational frequency range, predictable polarisation and gain. Due to the fact that a subsurface imaging system is essentially a short-range radar, the coupling between transmitting and receiving antennas has to be low and short in time. GPR antennas should have quick ring-down characteristics, in order to prevent masking of targets and guarantee a good resolution. The radiation patterns should ensure minimal interference with unwanted objects, usually present in the complex operational environment; to this aim, antennas should provide high directivity and concentrate the electromagnetic energy into a narrow solid angle. As GPR

  7. 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.

  8. Adjustment and beam forming in circular antenna array with conformal and phase scanning

    OpenAIRE

    Bobkov, Y; Yurtsev, O.; Moiseev, A.; Moskalev, D.

    2009-01-01

    The circular antenna array, composed of M linear antenna sub-arrays, is considered in this work. Every linear antenna sub-array includes N active modules. The signals from active antenna array modules in receive mode are processed in digital form. It is described the of the antenna phase adjustment, which is necessary for this type of antenna. It is also considered the influence of different factors to antenna radiation plot.

  9. Development of impedance matching technologies for ICRF antenna arrays

    International Nuclear Information System (INIS)

    All high power ICRF heating systems include devices for matching the input impedance of the antenna array to the generator output impedance. For most types of antennas used, the input impedance is strongly time-dependent on timescales as rapid as 10-4 s, while the rf generators used are capable of producing full power only into a stationary load impedance. Hence, the dynamic response of the matching method is of great practical importance. In this paper, world-wide developments in this field over the past decade are reviewed. These techniques may be divided into several classes. The edge plasma parameters that determine the antenna array's input impedance may be controlled to maintain a fixed load impedance. The frequency of the rf source can be feedback controlled to compensate for changes in the edge plasma conditions, or fast variable tuning elements in the transmission line between the generator output and the antenna input connections can provide the necessary time-varying impedance transformation. In lossy passive schemes, reflected power due to the time-varying impedance of the antenna array is diverted to a dummy load. Each of these techniques can be applied to a pre-existing antenna system. If a new antenna is to be designed, recent advances allow the antenna array to have the intrinsic property of presenting a constant load to the feeding transmission lines despite the varying load seen by each antenna in the array

  10. Array antenna diagnostics with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Meincke, Peter; Pivnenko, Sergey; Jørgensen, Erik

    The 3D reconstruction algorithm is applied to a slotted waveguide array measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. One slot of the array is covered by conductive tape and an error is present in the array excitation. Results show the accuracy obtainable by the 3D reconstru......The 3D reconstruction algorithm is applied to a slotted waveguide array measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. One slot of the array is covered by conductive tape and an error is present in the array excitation. Results show the accuracy obtainable by the 3D...

  11. The Submillimeter Array Antennas and Receivers

    Science.gov (United States)

    Blundell, R.

    The Submillimeter Array (SMA) was conceived at the Smithsonian Astrophysical Observatory in 1984 as a six element interferometer to operate in the major atmospheric windows from about 200 to 900 GHz. In 1996, the Academica Sinica Institute of Astronomy and Astrophysics of Taiwan joined the project and agreed to provide additional hardware to expand the interferometer to eight elements. All eight antennas are now operating at the observatory site on Mauna Kea, and astronomical observations have been made in the 230, 345, and 650 GHz bands. The SMA antennas have a diameter of 6 m, a surface accuracy of better than 25 micron rms, and can be reconfigured to provide spatial resolutions down to about 0.5" at 200 GHz and, eventually, 0.1" at 850 GHz. Coupling to the receiver package within each antenna is achieved via a beam waveguide, in a bent Nasmyth configuration, comprised of a flat tertiary mirror and two ellipsoidal mirrors that form a secondary pupil used for receiver calibration. An additional fixed mirror and a rotating wire grid polarizer are then used for receiver selection. Each antenna houses a single cryostat, with an integrated cryocooler capable of cooling up to eight receivers to 4 K. In the current configuration only three receiver bands are available: 175-255 GHz, 250-350 GHz, and 600-720 GHz, and simultaneous operation of the 650 GHz receiver with either of the lower frequency receivers is possible. Eventually dual polarization will be available from 325-350 GHz, and dual frequency operation will be possible, pairing either of the lower frequency receivers with any of the high frequency units: 325-425 GHz, 425-510 GHz, 600-720 GHz, and 800-900 GHz. Each receiver currently uses a single superconductor-insulator-superconductor junction as the mixing element, and has first stage intermediate frequency amplification at 4 K with an instantaneous bandwidth of 2.5 GHz, centered at 5 GHz. The mixers are of a fixed-tuned waveguide design, are inherently broad

  12. MIMO communications within the HF band using compact antenna arrays.

    OpenAIRE

    Gunashekar, S.D.; Warrington, E. M.; Feeney, S. M.; Salous, S.; Abbasi, N.M.

    2010-01-01

    Measurements have been made over a 255 km radio path between Durham and Leicester in the UK in order to investigate the potential applicability of multiple input multiple output (MIMO) techniques to communications within the HF band. This paper describes the results from experiments in which compact heterogeneous antenna arrays have been employed. The results of these experiments indicate that traditional spaced HF antenna arrays can be replaced by compact, active, heterogeneous arrays in ord...

  13. Integrated Solar-Panel Antenna Array for CubeSats

    Science.gov (United States)

    Baktur, Reyhan

    2016-01-01

    The goal of the Integrated Solar-Panel Antenna Array for CubeSats (ISAAC) project is to design and demonstrate an effective and efficien toptically transparent, high-gain, lightweight, conformal X-band antenna array that is integrated with the solar panels of a CubeSat. The targeted demonstration is for a Near Earth Network (NEN)radio at X-band, but the design can be easilyscaled to other network radios for higher frequencies. ISAAC is a less expensive and more flexible design for communication systemscompared to a deployed dish antenna or the existing integrated solar panel antenna design.

  14. Photonic Links for High-Performance Arraying of Antennas

    Science.gov (United States)

    Huang, Shouhua; Tjoelker, Robert

    2009-01-01

    An architecture for arraying microwave antennas in the next generation of NASA s Deep Space Network (DSN) involves the use of all photonic links between (1) the antennas in a given array and (2) a signal processing center. In this architecture, all affected parts at each antenna pedestal [except a front-end low-noise amplifier for the radio-frequency (RF) signal coming from the antenna and an optical transceiver to handle monitor and control (M/C) signals] would be passive optical parts

  15. Study of the characteristics of reconfigurable plasma antenna array

    Energy Technology Data Exchange (ETDEWEB)

    Alias, Nur Salihah; Dagang, Ahmad Nazri [School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu (Malaysia); Ali, Mohd Tarmizi [Microwave Technology Centre, Faculty of Electrical Engineering, Universiti Teknologi Mara Shah Alam 40450 Shah Alam, Selangor (Malaysia)

    2015-04-24

    This paper presents a design and simulation of a reconfigurable array of plasma antenna. The plasma column is used as radiating elements instead of metal to create an antenna. The advantages of the plasma antenna over the conventional antenna are its possible to change the operating parameters, such as the working pressure, input power, radius of the discharge tube, resonant frequency, and length of the plasma column. In addition, plasma antenna can be reconfigurable with respect to shape, frequency and radiation parameters in a very short time. The plasma discharge tube was designed with a length of 200 mm, the radius of the plasma column was 2.5 mm and the coupling sleeve was connected to the SMA as the ground. This simulation was performed by using the simulation software Computer Simulation Technology (CST). The frequency is set in the range of 1 GHz to 10 GHz. The performance of the designed antenna was analyzed in term of return loss, gain and radiation pattern. For reconfigurable plasma antenna array, it shows that the gain is increase when the number of antenna element is increase. The combination of the discharge tube and metal rod as an antenna array has been done, and the result shows that an array with the plasma element can achieve higher gain.

  16. A Transient UWB Antenna Array Used with Complex Impedance Surfaces

    Directory of Open Access Journals (Sweden)

    M. Brishoual

    2010-01-01

    Full Text Available The conception of a novel Ultra-Wideband (UWB antenna array, designed especially for transient radar applications through the frequency band (300 MHz–3 GHz, is proposed in this paper. For these applications, the elementary antenna must be compact and nondispersive, and the array must be able to steer in two dimensions. The geometry of the elementary antenna and its radiation characteristics are presented. The array beam steering is analyzed and a technique making the increase of the transient front-to-back ratio possible is described.

  17. Cooling System for a Ka Band Transmit Antenna Array

    OpenAIRE

    Döring, Björn

    2006-01-01

    Active antenna arrays working at higher frequencies result in higher packaging densities. The antenna array under consideration operates at about 30 GHz and will be installed in an aircraft. Commercially available power amplifiers at these frequencies have an efficiency of typically 20 %, which results in high amounts of dissipated heat for the required high radiated power. The dissipated power, up to 9.5 kW as a worst case for a 50 × 50 element array, has to be transfered from the antenna to...

  18. Beamformer for Cylindrical Conformal Array of Non-isotropic Antennas

    Directory of Open Access Journals (Sweden)

    ZOU, L.

    2011-02-01

    Full Text Available The principal objective of this investigation is to facilitate minimum variance distortionless response (MVDR beamforming technique for a cylindrical conformal array geometry. An array of directional radiating elements is postulated to cover a surface typical of the cylinder of an aircraft or missile. Borrowing the analysis of conformal array antennas, the authors first derive a deterministic expression that describes the beam pattern of arbitrary weighted cylindrical conformal array. Then, making use of the MVDR beamforming, we derive the beamformer for uniform linear array (ULA of directional antennas which are different from the traditional omnidirectional elements. Thus, the pattern of a directional element is synthesized by the antennas on the same ring array, and we design the MVDR beamformer, which uses MVDR beamforming for ULA of the synthesized pattern. To demonstrate the validity of the method, and cylinder arrays are constructed and experimental results agree well with theoretical expectations.

  19. Experiments with Compact Antenna Arrays for MIMO Radio Communications

    CERN Document Server

    Browne, D W; Fitz, M P; Rahmat-Samii, Y

    2005-01-01

    The problem tackled in this study is one of MIMO transceiver implementation in which we consider how to design and test compact antenna arrays that have the ability to preserve the native information bearing capacity of a MIMO channel. Mutual coupling in antenna arrays is known to degrade the performance of a MIMO system. However, no tests involving compact arrays have been performed using a MIMO transceiver architecture that is capable of measuring the effect of mutual coupling on system performance. In this study, two novel compact MIMO antenna arrays were designed and integrated into a wideband MIMO radio testbed. These arrays are extremely compact yet have acceptable mutual coupling and radiation efficiency and resonate in three wide frequency bands. A measurement campaign was executed in which MIMO channel sounding measurements were taken using the compact arrays and dipole arrays in a variety of indoor environments. The MIMO transceiver used for channel sounding is able to measure the effect of mutual c...

  20. Photonic spin-controlled multifunctional shared-aperture antenna array

    Science.gov (United States)

    Maguid, Elhanan; Yulevich, Igor; Veksler, Dekel; Kleiner, Vladimir; Brongersma, Mark L.; Hasman, Erez

    2016-06-01

    The shared-aperture phased antenna array developed in the field of radar applications is a promising approach for increased functionality in photonics. The alliance between the shared-aperture concepts and the geometric phase phenomenon arising from spin-orbit interaction provides a route to implement photonic spin-control multifunctional metasurfaces. We adopted a thinning technique within the shared-aperture synthesis and investigated interleaved sparse nanoantenna matrices and the spin-enabled asymmetric harmonic response to achieve helicity-controlled multiple structured wavefronts such as vortex beams carrying orbital angular momentum. We used multiplexed geometric phase profiles to simultaneously measure spectrum characteristics and the polarization state of light, enabling integrated on-chip spectropolarimetric analysis. The shared-aperture metasurface platform opens a pathway to novel types of nanophotonic functionality.

  1. Multi-element wire antenna array scattering characteristics numerical modeling

    OpenAIRE

    Bartsevich, A. V.; Bobkov, Yuri Y.; Al-Rifay, A.; Yurtsev, Oleg A.

    2007-01-01

    The new method of antenna scattering diagram and radar cross section calculation for multi-element wire antenna array is present in the work. The new method is combination of thin wire integral equation method and complex object RCS calculation method.

  2. Integrated Solar Array and Reflectarray Antenna for High Bandwidth Cubesats

    Science.gov (United States)

    Lewis, Dorothy; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Integrated Solar Array and Reflectarray Antenna (ISARA) mission will demonstrate a reflectarray antenna that increases downlink data rates for Cube- Sats from the existing baseline rate of 9.6 kilobits per second (kbps) to more than 100 megabits per second (Mbps). The ISARA spacecraft is slated for launch no earlier than Dec. 1, 2015.

  3. Phased-array antennas for future communication and sensor systems

    NARCIS (Netherlands)

    Vliet, F.E. van

    1998-01-01

    Traditionally, phased-array antenna systems have been exclusively used in radar systems. The development of these antennas has gained much momentum by the availability of integrated microwave components. Their flexibility and performance is reason to expect a much wider application in the coming yea

  4. Mathematical Simulating Model of Phased-Array Antenna in Multifunction Array Radar

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A mathematical simulating model of phased-array antenna in multifunction array radar has been approached in this paper, including the mathematical simulating model of plane phased-array pattern, the mathematical simulating model of directionality factor, the mathematical simulating model of array factor, the mathematical simulating model of array element factor and the mathematical simulating model of beam steering.

  5. Evolutionary Design of a Phased Array Antenna Element

    Science.gov (United States)

    Globus, Al; Linden, Derek; Lohn, Jason

    2006-01-01

    We present an evolved S-band phased array antenna element design that meets the requirements of NASA's TDRS-C communications satellite scheduled for launch early next decade. The original specification called for two types of elements, one for receive only and one for transmit/receive. We were able to evolve a single element design that meets both specifications thereby simplifying the antenna and reducing testing and integration costs. The highest performance antenna found using a genetic algorithm and stochastic hill-climbing has been fabricated and tested. Laboratory results are largely consistent with simulation. Researchers have been investigating evolutionary antenna design and optimization since the early 1990s, and the field has grown in recent years its computer speed has increased and electromagnetic simulators have improved. Many antenna types have been investigated, including wire antennas, antenna arrays and quadrifilar helical antennas. In particular, our laboratory evolved a wire antenna design for NASA's Space Technology 5 (ST5) spacecraft. This antenna has been fabricated, tested, and is scheduled for launch on the three spacecraft in 2006.

  6. Linear antenna array optimization using flower pollination algorithm.

    Science.gov (United States)

    Saxena, Prerna; Kothari, Ashwin

    2016-01-01

    Flower pollination algorithm (FPA) is a new nature-inspired evolutionary algorithm used to solve multi-objective optimization problems. The aim of this paper is to introduce FPA to the electromagnetics and antenna community for the optimization of linear antenna arrays. FPA is applied for the first time to linear array so as to obtain optimized antenna positions in order to achieve an array pattern with minimum side lobe level along with placement of deep nulls in desired directions. Various design examples are presented that illustrate the use of FPA for linear antenna array optimization, and subsequently the results are validated by benchmarking along with results obtained using other state-of-the-art, nature-inspired evolutionary algorithms such as particle swarm optimization, ant colony optimization and cat swarm optimization. The results suggest that in most cases, FPA outperforms the other evolutionary algorithms and at times it yields a similar performance. PMID:27066339

  7. Antenna-Coupled TES Bolometer Arrays for CMB Polarimetry Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop and test transition edge sensor (TES) bolometer arrays for precision polarimetry of cosmic microwave background (CMB).  Verify that critical antenna...

  8. Conformal Antenna Array for Millimeter-Wave Communications: Performance Evaluation

    CERN Document Server

    Semkin, V; Kyro, M; Kolmonen, V-M; Luxey, C; Ferrero, F; Devillers, F; Raisanen, A V

    2015-01-01

    In this paper, we study the influence of the radius of a cylindrical supporting structure on radiation properties of a conformal millimeter-wave antenna array. Bent antenna array structures on cylindrical surfaces may have important applications in future mobile devices. Small radii may be needed if the antenna is printed on the edges of mobile devices and in items which human beings are wearing, such as wrist watches, bracelets and rings. The antenna under study consists of four linear series-fed arrays of four patch elements and is operating at 58.8 GHz with linear polarization. The antenna array is fabricated on polytetrafluoroethylene substrate with thickness of 0.127 mm due to its good plasticity properties and low losses. Results for both planar and conformal antenna arrays show rather good agreement between simulation and measurements. The results show that conformal antenna structures allow achieving large angular coverage and may allow beam-steering implementations if switches are used to select betw...

  9. New submillimeter detectors and antenna arrays

    International Nuclear Information System (INIS)

    Preliminary investigation has been made into the use of SIS (superconductor--insulator--superconductor) diodes for possible roles in sub-millimeter imaging systems. That is, extremely low noise, millimeter wave detectors and mixers have recently been reported which depend on single-particle tunnelling between two superconducting films separated by a thin oxide layer. The combination of excellent low-frequency sensitivity and well-developed fabrication technology make the SIS mixers particularly attractive for the systems using antenna structures and arrays in millimeter and submillimeter regions. The SIS diodes of Nb-Nb2O5-Pb showed a strong video response to the radiation which could be differentiated from the regular Josephson effect since it was not affected by a magnetic field. In exploring the three-terminal devices for possible detector and source applications in submillimeter region, the authors first determined that millimeter and submillimeter radiation could be effectively coupled to and detected in high-frequency FETs. Video response was readily obtained at 800 GHz, and carcinotron radiation at 350 GHz was mixed with the 5th harmonic of a 70 GHz klystron, producing over 45 db signal-to-noise ratio in the intermediate frequency. Since FET can function as a three-terminal oscillator simultaneously detecting submillimeter radiation or optical beats, it has interesting possibility, such as self-oscillating mixers or subharmonic local oscillators. (Wakatsuki, Y.)

  10. Antenna-coupled bolometer arrays using transition-edgesensors

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael J.; Ade, Peter; Engargiola, Greg; Holzapfel,William; Lee,Adrian T.; O' Brient, Roger; Richards, Paul L.; Smith, Andy; Spieler, Helmuth; Tran, Huan

    2004-06-08

    We describe the development of an antenna-coupled bolometer array for use in a Cosmic Microwave Background polarization experiment. Prototype single pixels using double-slot dipole antennas and integrated microstrip band defining filters have been built and tested. Preliminary results of optical testing and simulations are presented. A bolometer array design based on this pixel will also be shown and future plans for application of the technology will be discussed.

  11. Antenna-coupled bolometer arrays using transition-edge sensors

    OpenAIRE

    Myers, Michael J.; Ade, Peter; Engargiola, Greg; Holzapfel, William; Lee, Adrian T.; O'Brient, Roger; Richards, Paul L.; Smith, Andy; Spieler, Helmuth; Tran, Huan

    2004-01-01

    We describe the development of an antenna-coupled bolometer array for use in a Cosmic Microwave Background polarization experiment. Prototype single pixels using double-slot dipole antennas and integrated microstrip band defining filters have been built and tested. Preliminary results of optical testing and simulations are presented. A bolometer array design based on this pixel will also be shown and future plans for application of the technology will be discussed.

  12. Coupled-oscillator based active-array antennas

    CERN Document Server

    Pogorzelski, Ronald J

    2012-01-01

    Describing an innovative approach to phased-array control in antenna design This book explores in detail phased-array antennas that use coupled-oscillator arrays, an arrangement featuring a remarkably simple beam steering control system and a major reduction in complexity compared with traditional methods of phased-array control. It brings together in one convenient, self-contained volume the many salient research results obtained over the past ten to fifteen years in laboratories around the world, including the California Institute of Technology's Jet Propulsion Laboratory.

  13. Series-Fed Microstrip Array Antenna with Circular Polarization

    OpenAIRE

    Tuan-Yung Han

    2012-01-01

    This study proposes a novel 2 × 2 array antenna design with broadband and circularly-polarized (CP) operation. The proposed design uses a simple series-fed network to increase the CP bandwidth without requiring one-by-one adjustment of each array element or a complex feed network. Selecting the appropriate spacing between each array element allows the proposed array antenna to generate CP radiation with a low axial ratio. Experimental results based on a prototype show that this 2 × 2 microstr...

  14. Imaging antenna array at 119 microns. [for plasma diagnostics

    Science.gov (United States)

    Neikirk, N. P.; Tong, P. P.; Putledge, D. B.; Park, H.; Young, P. E.

    1982-01-01

    A focal-plane imaging antenna array has been demonstrated at 119 microns. The array is a line of evaporated silver bow-tie antennas with bismuth microbolometer detectors on a silicon substrate. Radiation is coupled into the array by a lens placed on the back of the substrate. The bolometers are thermally isolated from the silicon substrate with a half-micron layer of polyimide. The array performance is demonstrated by coherent imaging of a series of holes at half the diffraction-limited cut-off frequency.

  15. Substrate Integrated Slot Array Antenna with Required Radiation Pattern Envelope

    OpenAIRE

    Zhou, M. M.; Cheng, Y. J.; W. N. Huang

    2016-01-01

    A substrate integrated slot array antenna with a prescribed radiation pattern is investigated in this paper. To meet the requirement of a certain standard radiation pattern envelope, the array configuration and the element excitation coefficient should be considered together. An efficient and systematic method is proposed to determine the element number and element weights in a planar array. After that, the geometrical dimension of the substrate integrated slot array can be synthesized. As an...

  16. Antenna-coupled bolometer arrays using transition-edge sensors

    International Nuclear Information System (INIS)

    We are developing antenna-coupled Transition-Edge Sensor (TES) bolometer arrays for use in measurements of the CMB polarization. TES bolometers have many well-known advantages over conventional bolometers, such as increased speed, linearity, and the existence of readout multiplexers. Antenna-coupled bolometers use an on-chip planar antenna to couple light into the bolometer. The antenna directivity and polarization sensitivity, along with the potential for on-chip band defining filters and channelizing circuits, allow a significant increase in focal plane integration. This eliminates the bulky horns, quasioptical filters, dichroics, and polarizers which might otherwise be needed in a conventional bolometric system. This simplification will ease the construction of receivers with larger numbers of pixels. We report on the fabrication and optical testing of single antenna-coupled bolometer pixels with integrated band defining filters. We will also discuss current progress on fabrication of a bolometer array based on this design

  17. Series-Fed Microstrip Array Antenna with Circular Polarization

    Directory of Open Access Journals (Sweden)

    Tuan-Yung Han

    2012-01-01

    Full Text Available This study proposes a novel 2 × 2 array antenna design with broadband and circularly-polarized (CP operation. The proposed design uses a simple series-fed network to increase the CP bandwidth without requiring one-by-one adjustment of each array element or a complex feed network. Selecting the appropriate spacing between each array element allows the proposed array antenna to generate CP radiation with a low axial ratio. Experimental results based on a prototype show that this 2 × 2 microstrip array antenna achieves a wide 3 dB axial ratio bandwidth of more than 10%. Simulated data are also provided to confirm the measured results.

  18. Microstrip Yagi array antenna for mobile satellite vehicle application

    Science.gov (United States)

    Huang, John; Densmore, Arthur C.

    1991-01-01

    A novel antenna structure formed by combining the Yagi-Uda array concept and the microstrip radiator technique is discussed. This antenna, called the microstrip Yagi array, has been developed for the mobile satellite (MSAT) system as a low-profile, low-cost, and mechanically steered medium-gain land-vehicle antenna. With the antenna's active patches (driven elements) and parasitic patches (reflector and director elements) located on the same horizontal plane, the main beam of the array can be tilted, by the effect of mutual coupling, in the elevation direction providing optimal coverage for users in the continental United States. Because the parasitic patches are not connected to any of the lossy RF power distributing circuit the antenna is an efficient radiating system. With the complete monopulse beamforming and power distributing circuits etched on a single thin stripline board underneath the microstrip Yagi array, the overall L-band antenna system has achieved a very low profile for vehicle's rooftop mounting, as well as a low manufacturing cost. Experimental results demonstrate the performance of this antenna.

  19. Connected Spiral Antennas for Wideband Circularly Polarized Antenna Array, Experimental Investigations

    OpenAIRE

    Serhir, Mohammed; Guinvarc'H, Régis

    2013-01-01

    International audience A cavity backed array of 5 connected spiral antennas is presented. The circular polarization is generated using mono polarized spirals in an alternating configuration RHCP and LHCP. Due to the connection between spirals, the currents in the arms of one spiral flow into the arms of the adjacent spirals. The currents transmitted to the opposite polarized neighboring spiral radiate the same polarization. The proposed antenna array allows more than 500MHz bandwidth while...

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

    Directory of Open Access Journals (Sweden)

    H. Aliakbarian

    2014-04-01

    Full Text Available 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 ground-space communication link. This paper describes the design, development and initial successful interim testing of the various subsystems. A two element prototype used in this increases the signal-to-noise ratio (SNR by 3 dB which is corresponding to more than 10 times better bit error rate (BER.

  1. Reconfigurable Plasma Antenna Array by Using Fluorescent Tube for Wi-Fi Application

    OpenAIRE

    H. Ja’afar; M. T. Ali; Dagang, A N; I. P. Ibrahim; N. A. Halili; H. M. Zali

    2016-01-01

    This paper presents a new design of reconfigurable plasma antenna array using commercial fluorescent tube. A round shape reconfigurable plasma antenna array is proposed to collimate beam radiated by an omnidirectional antenna (monopole antenna) operates at 2.4GHz in particular direction. The antenna design is consisted of monopole antenna located at the center of circular aluminum ground. The monopole antenna is surrounded by a cylindrical shell of conducting plasma. The plasma shield consist...

  2. Design and control of phased ICRF antenna arrays

    International Nuclear Information System (INIS)

    Phased antenna arrays operating in the ion cyclotron range of frequencies (ICRF) are used to produce highly directional wave spectra, primarily for use in current drive experiments. RF current drive using phased antennas has been demonstrated in both the JET and DIII-D tokamaks, and both devices are planning to operate new four-element arrays beginning early next year. Features of antenna design that are relevant to phased operation and production of directional spectra are reviewed. Recent advances in the design of the feed circuits and the related control systems for these arrays should substantially improve their performance, by reducing the coupling seen by the matching networks and rf power supplies caused by the mutual impedance of the array elements. The feed circuit designs for the DIII-D and JET phased antenna arrays are compared. The two configurations differ significantly due to the fact that one power amplifier is used for the entire array in the former case, and one per element in the latter. The JET system uses automatic feedback control of matching, phase and amplitude of antenna currents, and the transmitter power balance. The design of this system is discussed, and a time dependent model used to predict its behavior is described

  3. Flexible 16 Antenna Array for Microwave Breast Cancer Detection.

    Science.gov (United States)

    Bahramiabarghouei, Hadi; Porter, Emily; Santorelli, Adam; Gosselin, Benoit; Popović, Milica; Rusch, Leslie A

    2015-10-01

    Radar-based microwave imaging has been widely studied for breast cancer detection in recent times. Sensing dielectric property differences of tissues has been studied over a wide frequency band for this application. We design single- and dual-polarization antennas for wireless ultrawideband breast cancer detection systems using an inhomogeneous multilayer model of the human breast. Antennas made from flexible materials are more easily adapted to wearable applications. Miniaturized flexible monopole and spiral antennas on a 50-μm Kapton polyimide are designed, using a high-frequency structure simulator, to be in contact with biological breast tissues. The proposed antennas are designed to operate in a frequency range of 2-4 GHz (with reflection coefficient (S11) below -10 dB). Measurements show that the flexible antennas have good impedance matching when in different positions with different curvature around the breast. Our miniaturized flexible antennas are 20 mm × 20 mm. Furthermore, two flexible conformal 4 × 4 ultrawideband antenna arrays (single and dual polarization), in a format similar to that of a bra, were developed for a radar-based breast cancer detection system. By using a reflector for the arrays, the penetration of the propagated electromagnetic waves from the antennas into the breast can be improved by factors of 3.3 and 2.6, respectively. PMID:26011862

  4. 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...

  5. 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...

  6. Applications of trimode waveguide feeds in adaptive virtual array antennas

    Science.gov (United States)

    Allahgholi Pour, Z.; Shafai, Lotfollah

    2015-03-01

    This paper presents the formation of an adaptive virtual array antenna in a symmetric parabolic reflector antenna illuminated by trimode circular waveguide feeds with different mode alignments. The modes of interest are the TE11, TE21, and TM01 type modes. The terms TE and TM stand for the transverse electric and transverse magnetic modes, respectively. By appropriately exciting these modes and varying the mode orientations inside the primary feed, the effective source of radiation is displaced on the reflector aperture, while the resulting secondary patterns remain axial. Different antenna parameters such as gain, cross polarization, and phase center locations are investigated. It is demonstrated that the extra third mode facilitates the formation of symmetric virtual array antennas with reasonable cross polarization discriminations at the diagonal plane.

  7. Accurate Insertion Loss Measurements of the Juno Patch Array Antennas

    Science.gov (United States)

    Chamberlain, Neil; Chen, Jacqueline; Hodges, Richard; Demas, John

    2010-01-01

    This paper describes two independent methods for estimating the insertion loss of patch array antennas that were developed for the Juno Microwave Radiometer instrument. One method is based principally on pattern measurements while the other method is based solely on network analyzer measurements. The methods are accurate to within 0.1 dB for the measured antennas and show good agreement (to within 0.1dB) of separate radiometric measurements.

  8. X-band substrate integrated waveguide antenna arrays

    OpenAIRE

    Bobkov, Yuri Y.

    2014-01-01

    The article deal with linear waveguide-slot antenna based on rectangular waveguide integrated into the substrate printed circuit board (substrate integrated waveguide) and intended for use in a circular array with one-dimensional scanning. Antenna design is a multilayer printed circuit board of the microwave dielectrics in which the top and bottom metal layers play the role of wide wall of waveguide, and the narrow wall of waveguide is formed by a series of metalized pins.

  9. UNIFORMLY SPACED PLANAR ANTENNA ARRAY OPTIMIZATION USING CUCKOO SEARCH ALGORITHM

    Directory of Open Access Journals (Sweden)

    A.Sai Charan

    2014-05-01

    Full Text Available In this modern era a great deal of metamorphism is observed around us which eventuate due to some minute modifications and innovations in the area of Science and Technology. This paper deals with the application of a meta heuristic optimization algorithm namely the Cuckoo Search Algorithm in the design of an optimized planar antenna array which ensures high gain, directivity, suppression of side lobes, increased efficiency and improves other antenna parameters as well[1], [2] and [3].

  10. UNIFORMLY SPACED PLANAR ANTENNA ARRAY OPTIMIZATION USING CUCKOO SEARCH ALGORITHM

    OpenAIRE

    A.Sai Charan; Manasa, N. K.; N.V.S.N Sarma

    2014-01-01

    In this modern era a great deal of metamorphism is observed around us which eventuate due to some minute modifications and innovations in the area of Science and Technology. This paper deals with the application of a meta heuristic optimization algorithm namely the Cuckoo Search Algorithm in the design of an optimized planar antenna array which ensures high gain, directivity, suppression of side lobes, increased efficiency and improves other antenna parameters as well[1], [2] a...

  11. On the interference rejection capabilities of triangular antenna array for cellular base stations

    KAUST Repository

    Atat, Rachad

    2012-03-01

    In this paper, we present the performance analysis of the triangular antenna arrays in terms of the interference rejection capability. In this context, we derive an expression to calculate the spatial interference suppression coefficient for the triangular antenna array with variable number of antenna elements. The performance of the triangular antenna array has been compared with the circular antenna array with respect to interference suppression performance, steering beam pattern, beamwidth and directivity. Simulation results show that the triangular array with large number of elements produces a sharper beamwidth and better interference suppression performance than the circular antenna array. © 2012 IEEE.

  12. A 20 GHz circularly polarized, fan beam slot array antenna

    Science.gov (United States)

    Weikle, D. C.

    1982-03-01

    An EHF waveguide slot array was developed for possible use as a receive-only paging antenna for ground mobile terminals. The design, fabrication, and measured performance of this antenna are presented. The antenna generates a circularly polarized fan beam that is narrow in azimuth and broad in elevation. When mechanically rotated in azimuth, it can receive a 20 GHz satellite transmission independent of mobile terminal direction. Azimuth plane sidelobe levels, which are typically <-40 dB from the main lobe, provide for discrimination against ground and airborne jammers.

  13. The EoR Sensitivity of the 128 Antenna Murchison Widefield Array

    CERN Document Server

    Beardsley, A P; Morales, M F; Arcus, W; Barnes, D; Bernardi, G; Bowman, J D; Briggs, F H; Bunton, J D; Cappallo, R J; Corey, B E; Deshpande, A; deSouza, L; Emrich, D; Gaensler, B M; Goeke, R; Greenhill, L J; Herne, D; Hewitt, J N; Johnston-Hollit, M; Kaplan, D L; Kasper, J C; Kincaid, B B; Koenig, R; Kratzenberg, E; Lonsdale, C J; Lynch, M J; McWhirter, S R; Mitchell, D A; Morgan, E; Oberoi, D; Ord, S M; Pathikulangara, J; Prabu, T; Remillard, R A; Rogers, A E E; Roshi, A; Salah, J E; Sault, R J; Shankar, N Udaya; Srivani, K S; Stevens, J; Subrahmanyan, R; Tingay, S J; Wayth, R B; Waterson, M; Webster, R L; Whitney, A R; Williams, A; Williams, C L; Wyithe, J S B

    2012-01-01

    Using the planned antenna locations of the 128 antenna buildout of the Murchison Widefield Array (MWA), we accurately calculate its sensitivity to the Epoch of Reionization (EoR) power spectrum of redshifted 21 cm emission. Our calculation takes into account synthesis rotation, chromatic and asymmetrical baseline effects, and excludes modes that will be contaminated by foreground subtraction. With one full season of observation on two fields (900 and 700 hours), the MWA will be capable of a 14$\\sigma$ detection of the EoR signal along with slope constraints.

  14. Directional field enhancement of dielectric nano optical disc antenna arrays

    Science.gov (United States)

    Wang, Ivan; Du, Y.

    2011-11-01

    This paper presents a discussion on the directive field enhancement of dielectric disc antenna arrays in optical band. The property of dielectric material is addressed, and field modes in a cylindrical resonator are discussed. It is identified that the fundamental mode of HE 11δ generates the far field with a higher directivity than other modes. More effective field enhancement in the radiation direction could be achieved by using multiple-disc antenna arrays. Simulation examples indicate that the directivity of a disc antenna array varies with the disc spacing. The maximum directivity is observed when the disc spacing is approximately equal to the half of the vacuum wavelength. The maximum directivity can be improved significantly when the disc number is increased.

  15. Microstrip Phased Array Antennas Printed on Inclined Planes

    Directory of Open Access Journals (Sweden)

    A. Papiernik

    1996-06-01

    Full Text Available This paper presents an analysis of the electromagnetic field radiated by micro-strip patch antennas printed on inclined surfaces. The theoretical approach allows to apply spatial rotations to each source. The computer simulation developed permits us to experiment different antenna structures and two original realisations are proposed: a 2-element array printed on two inclined planes and a 4-element array laid out on a pyramidal surface. In addition, it enables the choice of the phase applied to each radiator to produce a beam deflection function. A good accuracy is obtained between theoretical and experimental results. The aim of this study is to optimise the parameters of such antennas to achieve the desired radiation patterns, from printed phased arrays on conformal surfaces. We also present the theoretical behaviour of a octagonal pyramid.

  16. Decoupling of Multifrequency Dipole Antenna Arrays for Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    R. Gonzalo

    2010-01-01

    Full Text Available The mutual coupling between elements of a multifrequency dipole antenna array is experimentally investigated by S-parameter measurements and planar near-field scanning of the radiated field. A multifrequency array with six dipoles is analyzed. In order to reduce the coupling between dipoles, a planar metasurface is placed atop the array acting as superstrate. The mutual coupling of the antenna elements in the absence and presence of the superstrate is presented comparatively. Between 3 and 20 dB mutual coupling reduction is achieved when the superstrate is used. By scanning the field radiated by the antennas and far-field measurements of the radiation pattern, it is observed that the superstrate confines the radiated power, increases the boresight radiation, and reduces the endfire radiation.

  17. Low profile conformal antenna arrays on high impedance substrate

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents electromagnetic (EM) design and analysis of dipole antenna array over high impedance substrate (HIS). HIS is a preferred substrate for low-profile antenna design, owing to its unique boundary conditions. Such substrates permit radiating elements to be printed on them without any disturbance in the radiation characteristics. Moreover HIS provides improved impedance matching, enhanced bandwidth, and increased broadside directivity owing to total reflection from the reactive surface and high input impedance. This book considers different configurations of HIS for array design on planar and non-planar high-impedance surfaces. Results are presented for cylindrical dipole, printed dipole, and folded dipole over single- and double-layered square-patch-based HIS and dogbone-based HIS. The performance of antenna arrays is analyzed in terms of performance parameters such as return loss and radiation pattern. The design presented shows acceptable return loss and mainlobe gain of radiation pattern. Thi...

  18. An estimation of directivity characteristics of antenna elements in antenna array with counting of signal conjugate components

    OpenAIRE

    Kopiievska, V. S.; Slyusar, Vadym I.

    2011-01-01

    In this article a two-stage digital processing of N-OFDM signals test sources for measurement of directivity characteristics (DC) of antenna elements in digital antenna array (DAA) with counting of complex conjugate components are presented.

  19. SAR Experiments Using a Conformal Antenna Array Radar Demonstrator

    Directory of Open Access Journals (Sweden)

    Peter Knott

    2012-01-01

    Full Text Available Conformal antenna arrays have been studied for several years but only few examples of applications in modern radar or communication systems may be found up to date due to technological difficulties. The objective of the “Electronic Radar with Conformal Array Antenna” (ERAKO demonstrator system which has been developed at the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR is to demonstrate the feasibility of an active electronically scanned antenna for conformal integration into small and medium sized airborne platforms. For practical trials the antenna has been adapted for operation with the Phased Array Multifunctional Imaging Radar (PAMIR system developed at the institute. The antenna in combination with the PAMIR front-end needed to undergo a special calibration procedure for beam forming and imaging post-processing. The present paper describes the design and development of the conformal antenna array of the demonstrator system, its connection to the PAMIR system and results of recently conducted synthetic aperture radar (SAR experiments.

  20. State-of-the-art and trends of Ground-Penetrating Radar antenna arrays

    Science.gov (United States)

    Vescovo, Roberto; Pajewski, Lara; Tosti, Fabio

    2016-04-01

    The aim of this contribution is to offer an overview on the antenna arrays for GPR systems, current trends and open issues. Antennas are a critical hardware component of a radar system, dictating its performance in terms of capability to detect targets. Nevertheless, most of the research efforts in the Ground-Penetrating Radar (GPR) area focus on the use of this imaging technique in a plethora of different applications and on the improvement of modelling/inversion/processing techniques, whereas a limited number of studies deal with technological issues related to the design of novel systems, including the synthesis, optimisation and characterisation of advanced antennas. Even fewer are the research activities carried out to develop innovative antenna arrays. GPR antennas operate in a strongly demanding environment and should satisfy a number of requirements, somehow unique and very different than those of conventional radar antennas. The same applies to GPR antenna arrays. The first requirement is an ultra-wide frequency band: the radar has to transmit and receive short-duration time-domain waveforms, in the order of a few nanoseconds, the time-duration of the emitted pulses being a trade-off between the desired radar resolution and penetration depth. Furthermore, GPR antennas should have a linear phase characteristic over the whole operational frequency range, predictable polarisation and gain. Due to the fact that a subsurface imaging system is essentially a short-range radar, the coupling between transmitting and receiving antennas has to be low and short in time. GPR antennas should have quick ring-down characteristics, in order to prevent masking of targets and guarantee a good resolution. The radiation patterns should ensure minimal interference with unwanted objects, usually present in the complex operational environment; to this aim, antennas should provide high directivity and concentrate the electromagnetic energy into a narrow solid angle. As GPR

  1. 2D Active Antenna Array Design for FD-MIMO System and Antenna Virtualization Techniques

    Directory of Open Access Journals (Sweden)

    Ioannis Tzanidis

    2015-01-01

    Full Text Available Full dimension MIMO (FD-MIMO is one of the key technologies presently studied in the 3GPP for the next generation long-term evolution advanced (LTE-A systems. By incorporating FD-MIMO into LTE/LTE-A systems, it is expected that system throughput will be drastically improved beyond what is possible in conventional LTE systems. This paper presets details on the 2D active antenna array design for FD-MIMO systems supporting 32 antenna elements. The FD-MIMO system allows for dynamic and adaptive precoding to be performed jointly across all antennas thus achieving more directional transmissions in the azimuth and elevation domains simultaneously, to a larger number of users. Finally, we discuss 2D antenna array port virtualization techniques for creating beams with wide coverage, necessary for broadcasting signals to all users within a sector, such as the CRS (Common Reference Signal.

  2. Theoretical analysis of ion cyclotron range of frequency antenna array for HT-7U

    Institute of Scientific and Technical Information of China (English)

    Zhang Xin-Jun; Qin Cheng-Ming; Zhao Yan-Ping

    2005-01-01

    This paper considers the coupling analysis of phased antenna array designed to excite fast wave in the ion cyclotron range of frequency. The coupling of the antenna is calculated in slab geometry. The coupling code based on the variational principle gives the self-consistent current flowing in the antenna, this method has been extended so that it can be applied to a phased antenna array. As an example, this paper analyses the coupling prosperities of a 2×2phased antenna array. It gives the optimum geometry of antenna array. The fields excited at plasma surface are found to more or less correspond to the antenna current phasing.

  3. Optimization of an antenna array using genetic algorithms

    International Nuclear Information System (INIS)

    An array of antennas is usually used in long distance communication. The observation of celestial objects necessitates a large array of antennas, such as the Giant Metrewave Radio Telescope (GMRT). Optimizing this kind of array is very important when observing a high performance system. The genetic algorithm (GA) is an optimization solution for these kinds of problems that reconfigures the position of antennas to increase the u-v coverage plane or decrease the sidelobe levels (SLLs). This paper presents how to optimize a correlator antenna array using the GA. A brief explanation about the GA and operators used in this paper (mutation and crossover) is provided. Then, the results of optimization are discussed. The results show that the GA provides efficient and optimum solutions among a pool of candidate solutions in order to achieve the desired array performance for the purposes of radio astronomy. The proposed algorithm is able to distribute the u-v plane more efficiently than GMRT with a more than 95% distribution ratio at snapshot, and to fill the u-v plane from a 20% to more than 68% filling ratio as the number of generations increases in the hour tracking observations. Finally, the algorithm is able to reduce the SLL to –21.75 dB.

  4. Radiation Characteristics of Rectangular Patch Antennas with an Array of Pins

    Institute of Scientific and Technical Information of China (English)

    Myung-ki CHO; Tae-young KIM; Boo-gyoun KIM

    2010-01-01

    The patch antennas with an array of pins (pin array patch antennas) with excellent radiation characteristics are investigated for various substrate thicknesses.The radiation in the horizontal plane of a pin array patch antenna is very small campared to that of a conventional patch antenna.And the increase of forward radiation and the decrease of backward radiation of a pin array patch antenna are tained than these conventional one's.Also the half-power beamwidth of E-plane radiation pattern of a pin array patch antenna is narrower compared to that of the conventional so that the directivity is improved.

  5. Generation of OAM Radio Waves Using Circular Vivaldi Antenna Array

    Directory of Open Access Journals (Sweden)

    Changjiang Deng

    2013-01-01

    Full Text Available This paper gives a feasible and simple solution of generating OAM-carrying radio beams. Eight Vivaldi antenna elements connect sequentially and fold into a hollow cylinder. The circular Vivaldi antenna array is fed with unit amplitude but with a successive phase difference from element to element. By changing the phase difference at the steps of 0, ±45°, ±90°, ±135°, and 180°, the OAM radio beam can be generated with mode numbers 0, ±1, ±2, ±3, and 4. Simulations show that the OAM states of ±2 and ±3 are the same as the traditional states, while the OAM states of 0, ±1, and 4 differ at the boresight. This phenomenon can be explained by the radiation pattern difference between Vivaldi antenna and tripole antenna. A solution of distinguishing OAM states is also proposed. The mode number of OAM can be distinguished with only 2 receivers.

  6. Flexible sixteen monopole antenna array for microwave breast cancer detection.

    Science.gov (United States)

    Bahrami, H; Porter, E; Santorelli, A; Gosselin, B; Popovic, M; Rusch, L A

    2014-01-01

    Radar based microwave imaging (MI) has been widely studied for breast cancer detection in recent times. Sensing dielectric property differences of tissues over a wide frequency band has been made possible by ultra-wideband (UWB) techniques. In this paper, a flexible, compact monopole antenna on a 100 μm Kapton polyimide is designed, using a high frequency structure simulator (HFSS), to be in contact with biological breast tissues over the 2-5GHz frequency range. The antenna parameters are optimized to obtain a good impedance match over the required frequency range. The designed antenna size is 18mm × 18mm. Further, a flexible conformal 4×4 ultra-wideband antenna array, in a format similar to that of a bra, was developed for a radar-based breast cancer detection system. PMID:25570813

  7. A planar parasitic array antenna for tunable radiation pattern

    OpenAIRE

    Seongheon, Jeong; Dohyuk, Ha; Chappell, W. J.

    2009-01-01

    In this paper, a cross-type parasitic array antenna is designed to tune the radiation pattern which attenuates incoming interference and improve packet reception. Using only a 5-element planar array allows full 2-dimensional beam steering. The measurement shows that approximately 30 degrees of beam steering can be achieved by terminating parasitic elements with commercial Si-based varactors allowing rapid and auto...

  8. ANTENNA ARRAY WITH ELECTRONIC BEAM STEERING FOR TELECOMMUNICATION APPLICATIONS

    OpenAIRE

    Ali Akbarian, Hadi; Volskiy, Vladimir; Vandenbosch, Guy

    2010-01-01

    Electronically controlled beam steering array antennas highly increase the performance of telecommunication links by improving the link budget. Moreover, digital (baseband) beam steering includes the possibility of having multiple beams simultaneously and of communicating with more than one user at the same time. The basics of digital beam forming are explained in this paper. A 1x2 prototype array with digital beam steering is introduced and measurement results are shown.

  9. Study of LCP based flexible patch antenna array

    KAUST Repository

    Ghaffar, Farhan A.

    2012-07-01

    Wrapping of a two element LCP based patch antenna array is studied in this work. For the first time, the designed array is bent in both E and H planes to observe the effect on the radiation and impedance performance of the antenna. The 38 GHz simulation results reveal better performance for H plane bending as compared to E plane bending. A 100 um thick substrate is used for the design which is best suited for flexible antenna applications. Gain variations of 1.1 dB and 1.4 dB are observed for the two orientations while a significantly increased impedance bandwidth of 3 % is obtained with H plane wrapping. The design is highly suitable for broadband micro-cellular backhaul applications. © 2012 IEEE.

  10. Antenna-coupled TES bolometer arrays for CMB polarimetry

    CERN Document Server

    Kuo, C L; Bonetti, J A; Brevik, J; Chattopadhyay, G; Day, P K; Golwala, S; Kenyon, M; Lange, A E; LeDuc, H G; Nguyen, H; Ogburn, R W; Orlando, A; Trangsrud, A; Turner, A; Wang, G; Zmuidzinas, J; 10.1117/12.788588

    2009-01-01

    We describe the design and performance of polarization selective antenna-coupled TES arrays that will be used in several upcoming Cosmic Microwave Background (CMB) experiments: SPIDER, BICEP-2/SPUD. The fully lithographic polarimeter arrays utilize planar phased-antennas for collimation (F/4 beam) and microstrip filters for band definition (25% bandwidth). These devices demonstrate high optical efficiency, excellent beam shapes, and well-defined spectral bands. The dual-polarization antennas provide well-matched beams and low cross polarization response, both important for high-fidelity polarization measurements. These devices have so far been developed for the 100 GHz and 150 GHz bands, two premier millimeter-wave atmospheric windows for CMB observations. In the near future, the flexible microstrip-coupled architecture can provide photon noise-limited detection for the entire frequency range of the CMBPOL mission. This paper is a summary of the progress we have made since the 2006 SPIE meeting in Orlando, FL...

  11. CAD of waveguide array antennas based on "filter" concepts

    NARCIS (Netherlands)

    Visser, H.J.; Guglielmi, M.

    1999-01-01

    In this paper an alternative approach for the design of open-ended waveguide array antennas is presented. The approach is based on microwave filter concepts. The exploitation of this alternative viewpoint has been made possible by the availability of a very efficient computer-aided design (CAD) tool

  12. Sunflower array antenna for multi-beam satellite applications

    NARCIS (Netherlands)

    Vigano, M.C.

    2011-01-01

    Saving space on board, reducing costs and improving the antenna performances are tasks of outmost importance in the field of satellite communication. In this work it is shown how a non-uniformly spaced, direct radiating array designed according to the so called ‘sunflower’ law is able to satisfy str

  13. Monolithic microwave integrated circuit with integral array antenna

    International Nuclear Information System (INIS)

    A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single substrate by means of a controlled fabrication process sequence

  14. Comparison of an electrically-small planar antenna array with a conventional monopole array

    OpenAIRE

    Rogers, PR; Hilton, GS; Craddock, IJ; Fletcher, PN

    2002-01-01

    A new type of linear array is proposed which utilises annular slot antennas operating in the 'DC' mode. These conformal elements are electrically-small and have wire-monopole-like radiation patterns. A thorough analysis of this array's performance is provided, with a comparison against the performance of an equivalent wire monopole array given at each stage. It is shown that, overall, the characteristics of the conformal, electrically-small, annular-slot array are very similar to that of the ...

  15. Antenna synthesis based on the ant colony optimization algorithm

    OpenAIRE

    Slyusar, V. I.; Ermolaev, S. Y.

    2009-01-01

    This report are described the versions and the synthesis results of new designs of electrically small antenna based on ant colony optimization algorithms. To study the parameters of the frame and non-loopback vibrators MMANA package was used. Geometric forms that were obtained might be used as contour lines of printed, slot antenna or as forming surface of the crystal dielectric resonator antenna. A constructive meta-heuristic search algorithm for optimization of the antennas form...

  16. 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.

  17. Low Cost Phased Array Antenna System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A program is proposed to research the applicability of a unique phased array technology, dubbed FlexScan, to S-band and Ku-band communications links between...

  18. GNSS antenna array-aided CORS ambiguity resolution

    Science.gov (United States)

    Li, Bofeng; Teunissen, Peter J. G.

    2014-04-01

    Array-aided precise point positioning is a measurement concept that uses GNSS data, from multiple antennas in an array of known geometry, to realize improved GNSS parameter estimation proposed by Teunissen (IEEE Trans Signal Process 60:2870-2881, 2012). In this contribution, the benefits of array-aided CORS ambiguity resolution are explored. The mathematical model is formulated to show how the platform-array data can be reduced and how the variance matrix of the between-platform ambiguities can profit from the increased precision of the reduced platform data. The ambiguity resolution performance will be demonstrated for varying scenarios using simulation. We consider single-, dual- and triple-frequency scenarios of geometry-based and geometry-free models for different number of antennas and different standard deviations of the ionosphere-weighted constraints. The performances of both full and partial ambiguity resolution (PAR) are presented for these different scenarios. As the study shows, when full advantage is taken of the array antennas, both full and partial ambiguity resolution can be significantly improved, in some important cases even enabling instantaneous ambiguity resolution. PAR widelaning and its suboptimal character are hereby also illustrated.

  19. Modeling and simulation of Microstrip patch array for smart antennas

    Directory of Open Access Journals (Sweden)

    K.Meena alias Jeyanthi

    2010-01-01

    Full Text Available The aim of the paper is two fold. One is to design and simulate an antenna array suitable for wireless applications and the other is the design of beamforming algorithm. In this paper, the first module presents the design of multiple microstrip rectangular patch elements suitable for beamforming technique in wireless applications in the range of 1.8 - 2.4 GHz. By designing 1x8 patch array, it is possible to achieve 15 dB gain and 58% more directivity compared to the conventional patches. The second module suggests a NLVFF-RLS algorithm for beamforming technique to concentrate the power in the desired direction and nullify the power in the interferer direction with HPBW of 13dB.The results are analyzed for the scanning sector of -60° to 60°. The modeling and simulation of antenna array is obtained using Agilent’s ADS. The beamforming algorithm is designed in Matlab.

  20. Search space scanning with planar electronically-controlled array antennas

    Science.gov (United States)

    Hanle, E.

    The demands which radar installations have to satisfy are rising with increasing traffic density in the case of civil applications and a growing threat level in the case of the military sector. In many instances, these demands can only be met by adapting the value of the transmitted power to the traffic density or the magnitude of the threat. Such an approach requires the employment of computer-aided radar systems with electronically-controlled antennas. The considered systems have currently also advantages with respect to reliability and cost effectiveness. The present investigation is concerned with suitable procedures for the improvement of the energy management, taking into account mainly aspects of radar control and signal processing. The discussion is based on the consideration of a planar array antenna. Differences arising in connection with the use of other types of antennas are also briefly examined. The employment of an immobile radar antenna for ground-based airspace observation is considered. Attention is given to the appropriate selection of the width of the lobe, the scanning, the tilt of the antenna, and antenna performance characteristics.

  1. Metallic post-array loaded cylindrical dielectric resonator antenna

    Directory of Open Access Journals (Sweden)

    Byeong-Yong Park

    2016-01-01

    Full Text Available An investigation of a novel cylindrical dielectric resonator antenna (DRA configuration has been carried out. It is shown that two resonances including the full- and half-cylindrical HE(11δ-like modes can coexist simultaneously at different frequencies by placing a metallic post array in the resonator. Moreover, compared with the conventional HE(11δ mode cylindrical DRA having the same size, the proposed antenna operates in lower frequency band and shows improved bandwidth. The experimental results including the return loss and the radiation patterns are demonstrated.

  2. 0.6-M Antennae for the Amiba Interferometry Array

    Science.gov (United States)

    Koch, P.; Raffin, P. A.; Proty Wu, J.-H.; et al.

    2006-10-01

    The Array for Microwave Background Anisotropy (AMiBA) is a hexapod telescope for astronomy. The fully steerable platform can accommodate up to 19 dishes. We present the design, simulation, manufacturing and performance verification for the 0.6m Cassegrain antennae. The primary and secondary mirrors are carbon fiber sandwich structures, manufactured by CoTec Inc., in Taichung, Taiwan. They are aluminium coated with a final surface rms of 20-30 and 10 μm, respectively. Simulated load conditions for the mirrors show maximum rms surface errors of less than 10 μm. The measured antenna beam pattern confirms the expected performance.

  3. Human tracking using a two-element antenna array

    Science.gov (United States)

    Lin, Adrian; Ling, Hao

    2005-05-01

    We investigate the use of a low-cost, two-element receiving array for tracking human movements in indoor surveillance applications. Conventional direction of arrival (DOA) detection requires the use of an antenna array with multiple elements. Here we investigate the use of only two elements in the receiver array. The concept entails simultaneously resolving the Doppler frequencies of the returned signals from the moving targets and the DOA of the targets. Simulation is performed to demonstrate the concept. Both the monostatic and the bistatic scenario where the transmitter and the receiving array are placed at different locations are investigated. DOA errors and tolerances are analyzed for each scenario. An experimental system is constructed to test the concept. The system consists of a two-element receiver array operating at 2.4 GHz. Measurement results of various collection scenarios are presented.

  4. Coplanar waveguide feeds for phased array antennas

    Science.gov (United States)

    Simons, Rainee N.; Lee, Richard Q.

    1992-08-01

    The design and performance of the following coplanar waveguide (CPW) microwave distribution networks for linear as well as circularly polarized microstrip patches and printed dipole arrays is presented: (1) CPW/microstrip line feed; (2) CPW/balanced stripline feed; (3) CPW/slotline feed; (4) grounded CPW (GCPW)/balanced coplanar stripline feed; and (5) CPW/slot coupled feed. Typical measured radiation patterns are presented, and their relative advantages and disadvantages are compared.

  5. MIMO Communication Using Single Feed Antenna Arrays

    DEFF Research Database (Denmark)

    Alrabadi, Osama

    Multi-input-multi-output (MIMO) communication has emerged as a promis- ing technology for meeting the increasing demand on higher data rates. The technology exploits the spatial resource dimension by sending the datas- treams to different locations in the multi element array (MEA) domain while...... prototype. The experiments show that the proposed beamspace MIMO approach provides performance compara- ble to a conventional MIMO system, but at a reduced size and hardware complexity....

  6. DUAL POLARIZATION ANTENNA ARRAY WITH VERY LOW CROSS POLARIZATION AND LOW SIDE LOBES

    DEFF Research Database (Denmark)

    1997-01-01

    The present invention relates to an antenna array adapted to radiate or receive electromagnetic waves of one or two polarizations with very low cross polarization and low side lobes. An antenna array comprising many antenna elements, e.g. more than ten antenna elements, is provided in which...... formation of grating lobes are inhibited in selected directions of the radiation and cross polarization within the main lobe is suppressed at least 30 dB below the main lobe peak value. According to a preferred embodiment of the invention, the antenna elements of the antenna array comprise probe-fed patches...

  7. 60 GHz SIW Steerable Antenna Array in LTCC

    Institute of Scientific and Technical Information of China (English)

    Bahram Sanadgol; Sybille Holzwarth; Peter Uhlig; Alberto Milano; Raft Popovich

    2012-01-01

    In this paper, we present a 60 GHz substrate-integrated waveguide fed-steerable low-temperature cofired ceramics array. The antenna is suitable for transmitting and receiving on the 60 GHz wireless personal area network frequency band. The wireless system can be used for HDTV, high-data-rate networking up to 4.5 GBit/s, security and surveillance, and similar applications.

  8. Delivering both sum and difference beam distributions to a planar monopulse antenna array

    Energy Technology Data Exchange (ETDEWEB)

    Strassner, II, Bernd H.

    2015-12-22

    A planar monopulse radar apparatus includes a planar distribution matrix coupled to a planar antenna array having a linear configuration of antenna elements. The planar distribution matrix is responsive to first and second pluralities of weights applied thereto for providing both sum and difference beam distributions across the antenna array.

  9. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics.

    Science.gov (United States)

    Kuwahara, D; Ito, N; Nagayama, Y; Yoshinaga, T; Yamaguchi, S; Yoshikawa, M; Kohagura, J; Sugito, S; Kogi, Y; Mase, A

    2014-11-01

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array. PMID:25430218

  10. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, D., E-mail: dkuwahar@cc.tuat.ac.jp [Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Ito, N. [Department of Intelligent System Engineering, Ube National College of Technology, Ube, Yamaguchi 755-8555 (Japan); Nagayama, Y. [Department of Helical Plasma Research, National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Yoshinaga, T. [Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa 239-0811 (Japan); Yamaguchi, S. [Department of Pure and Applied Physics, Kansai University, Suita, Osaka 564-8680 (Japan); Yoshikawa, M.; Kohagura, J. [Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Sugito, S. [Equipment Development Center, Institute for Molecular Science, Okazaki, Aichi 444-8585 (Japan); Kogi, Y. [Department of Information Electronics, Fukuoka Institute of Technology, Fukuoka, Fukuoka 811-0295 (Japan); Mase, A. [Art, Science and Technology Center for Cooperative Research, Kyusyu University, Kasuga, Fukuoka 816-8580 (Japan)

    2014-11-15

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

  11. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    International Nuclear Information System (INIS)

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array

  12. Flat Array Antennas for Ku-Band Mobile Satellite Terminals

    Directory of Open Access Journals (Sweden)

    Roberto Vincenti Gatti

    2009-01-01

    Full Text Available This work presents the advances in the development of two innovative flat array antennas for Ku-band mobile satellite terminals. The first antenna is specifically conceived for double-deck trains to allow a bi-directional high data rate satellite link. The available circular surface (diameter 80 cm integrates both a transmitting and a receiving section, operating in orthogonal linear polarizations. The TX frequency range is fully covered while the RX bandwidth is around 1 GHz arbitrarily allocated on the DVB range depending on requirements. The beam is steered in elevation through a phased array architecture not employing costly phase shifters, while the steering in azimuth is mechanical. Active BFNs allow excellent performance in terms of EIRP and G/T, maintaining extremely low profile. High antenna efficiency and low fabrication cost are ensured by the employment of innovative SIW (Substrate Integrated Waveguide structures. The second antenna, receiving-only, is designed for radio/video streaming services in mobile environment. Full DVB coverage is achieved thanks to cavity-backed patches operating in double linear polarization. Two independent broadband active BFNs allow simultaneous reception of both polarizations with full tracking capabilities and a squintless beam steering from 20∘ to 60∘ in elevation. A minimum gain of 20 dBi and G/T >−3 dB/K∘ are achieved, while maintaining extremely compact size and flat profile. In the design of both antennas fabrication cost is considered as a driving factor, yet providing high performance with a flat profile and thus resulting in a great commercial potentiality.

  13. A Multi-Band Photonic Phased Array Antenna for High-Data Rate Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

  14. A Multi-band Photonic Phased Array Antenna for High-Date Rate Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

  15. Double Exchange Genetic Algorithm for the Synthesis of Linear Array

    Directory of Open Access Journals (Sweden)

    Zhang Jian-Hua

    2012-01-01

    Full Text Available The development of Synthesis of Linear array put forward higher request for complex optimization solutions. This article improves the basic genetic algorithm according to the traditional genetic algorithm easily prematuring convergence and later evolution slow convergence shortcoming. And then, adopt double exchange operator in reproductive strategies and implement dynamic mutation rate in variation operations. Combined characteristics of guarantee to the population diversity based on fitness shared niche while iteration times exponential diminishing, this article creats niche double exchangegenetic algorithm, and applies in pattern synthesis of homogeneous linear array, and simulates multi-objective complex array problem. The result turns out much better in effectively preventing premature and improving the searching efficiency of genetic algorithm than original genetic algorithm and immune genetic algorithm, what will achieve the broad prospect in the antenna array comprehensive field.

  16. Optical SideBand Filtering in an optical beam forming system for phased-array antennas

    OpenAIRE

    Peña Hevilla, J.

    2007-01-01

    Directionally controlled antennas — or phased array antennas — are widely used in many mobile telecom markets and recently they have a space in consumer products and transport vehicles, as an aircraft, ships, etcetera. In this project, the field of interest will be the satellite comunications between a satellite transmitter and an aircraft using a DVB-S signal. Smart antennas in either transmission or reception have a directionally controlled radiation beam based on multiple antenna array ele...

  17. Band width of micro strip antenna improved by using parasitic array

    Directory of Open Access Journals (Sweden)

    Ajay kumar

    2013-01-01

    Full Text Available In this paper we present the surface wave of microstrip antenna reduce by using parasitic array at the patch ,it is a wide band antenna and frequency range of this wide band antenna lie from 1.168GHz-3.854GHz.The proposed antenna is simulated by using IE3D simulated software. This antenna can be used in WiMax,Bluetooth and Wireless communication.

  18. Band width of micro strip antenna improved by using parasitic array

    OpenAIRE

    Ajay kumar; Srivastava, D. K.; Dwejendra Arya

    2013-01-01

    In this paper we present the surface wave of microstrip antenna reduce by using parasitic array at the patch ,it is a wide band antenna and frequency range of this wide band antenna lie from 1.168GHz-3.854GHz.The proposed antenna is simulated by using IE3D simulated software. This antenna can be used in WiMax,Bluetooth and Wireless communication.

  19. New approaches to analysis and synthesis of reflector antennas

    Science.gov (United States)

    Galindo-Israel, V.; Mittra, R.

    1978-01-01

    Recently developed techniques are reviewed for analyzing and synthesizing single and dual antennas for high efficiency and wide angle scan. The problem of contour beam synthesis using superposition of pencil beams is also discussed.

  20. Optical implementation for adaptive beamforming of array antenna

    Science.gov (United States)

    Liu, Ming; Shi, Xiang quan

    2010-11-01

    It is difficult for the traditional phased array radar to process large array-element and high time-bandwidth-product signal in real time. An optical architecture of implement true time delay adaptive beamforming based on Stimulate Photon Echoes(SPE) is introduced. The principle of how to implement a true time delay based on SPE phenomenon with its theory models is established. the method of how to implement variable time delays using laser beams modulated by linear frequency chirped pulses is discussed, the relationship between chirp bandwidth and delay step is demonstrated by simulation results. As a result, it allows to filter thousands of simultaneous AOAs with 30 GHz dynamically in both spatial and spectral domains, which can be used to adaptively steer a large RF phased array antenna toward the direction of interest while minimizing the effects of unwanted interference signals.

  1. Beam steerable IR-UWB antenna array with FCC-compliant impulse generators

    OpenAIRE

    Schleicher, Bernd; Leib, Mario; Menzel, Wolfgang; Schumacher, Hermann

    2010-01-01

    A novel method for beam steering with an active ultra-wideband antenna array is presented for impulse-radio ultra-wideband. The antenna array consists of four planar Vivaldi antennas in a collinear arrangement with an impulse generator circuit mounted chip-on-board on each antenna element. The beam steering is done by shifting the phase of the control signals triggering the impulse generators. In the array arrangement a measured beam width of 16° is achieved for an antenna spacing of 4 cm com...

  2. Optimization of the ITER Ion Cyclotron Heating Antenna Array

    Science.gov (United States)

    Ryan, P. M.; Swain, D. W.; Carter, M. D.; Taylor, D. J.; Bosia, G.; D'Ippolito, D. A.; Myra, J. R.

    1996-11-01

    The present design of the ITER ICH antenna array comprises two poloidal by four toroidal current elements in each of four ports. Each current element forms a resonant double loop (RDL) with power fed to a pretuned matchpoint on the strap; the matching is accomplished using slow-wave transmission lines as adjustable shorted-stub tuners on either end of the current strap. The power requirement is 12.5 MW per port over the frequency range of 40--70 MHz, with extended operation to 80 MHz desirable. The antenna design optimization process includes strap shaping to minimize strap voltages and rf E-fields along B-field lines, (2) frame/Faraday shield geometry design to improve plasma coupling, wave spectrum directivity, and phase control, and (3) Faraday shield/bumper geometry to minimize rf sheath-induced structure heating and impurity generation.

  3. Reconfigurable Pico-cell Antenna Array for Indoor Coverage in GSM 900 Band

    Directory of Open Access Journals (Sweden)

    B. Ivsic

    2009-12-01

    Full Text Available This paper proposes a simple antenna array based on three stacked shorted patches aimed to be used as GSM (900 MHz indoor base station antenna. Three same linearly polarized stacked patches are set in three orthogonal planes in space forming pyramid-like structure. The antenna array can be used for nearly omnidirectional coverage as well as for covering three 120º sectors. The proposed array also offers the possibility of polarization diversity.

  4. Development of 2-D antenna array for microwave imaging reflectometry in LHD

    International Nuclear Information System (INIS)

    A 2-D antenna array for the Microwave Imaging Reflectometry (MIR) has been developed for the Large Helical Device (LHD). The MIR is a method of electron density diagnostics by the use of microwave radar techniques to obtain 2-D/3-D images of electron density fluctuations for the investigation of micro-turbulence and magneto-hydrodynamic instabilities in magnetically confined plasmas. The antenna array consists of five antennas in the toroidal direction and eight ones in the poloidal direction, respectively. As a test of an antenna element, a pyramidal horn antenna in the frequency range of 10-15 GHz was compared with the Yagi-Uda antenna. Based on the test results of the lower frequency antenna element, we manufactured a 2-D horn antenna array in the frequency range of 50-75 GHz. (author)

  5. Microstrip Antennas with Polarization Diversity across a Wide Frequency Range and Phased Array Antennas for Radar and Satellite Communications

    Science.gov (United States)

    Ho, Kevin Ming-Jiang

    The thesis comprises of 3 projects; an L-band microstrip antenna with frequency agility and polarization diversity, X-band phased array antennas incorporating commercially packaged RFIC phased array chips, and studies for Ku/Ka-band shared aperture antenna array. The first project features the use of commercially packaged RF-MEMS SPDT switches, that boasts of high reliability, high linearity, low losses, hermetically packaged and fully compatible for SMTA processes for mass-assembly and production. Using the switches in a novel manner for the feed network, microstrip antennas with polarization diversity are presented. Frequency agility is achieved with the use of tuning diodes to provide capacitive loading to the antenna element. Additional inductance effects from surface-mounted capacitors, and its impact, is introduced. Theoretical cross-polarization of probe-fed antenna elements is presented for both linear and circular polarized microstrip antennas. Designs and measurements are presented, for microstrip antennas with polarization diversity, wide frequency tuning range, and both features. Replacement of the tuning diodes with commercially-packaged high Q RF MEMS tunable capacitors will allow for significant improvements to the radiation efficiency. In another project, multi-channel CMOS RFIC phased-array receiver chips are assembled in QFN packages and directly integrated on the same multi-layered PCB stack-up with the antenna arrays. Problems of isolation from the PCB-QFN interface, and potential performance degradation on antenna array from the use of commercial-grade laminates for assembly requirements, namely potential scan blindness and radiation efficiency, are presented. Causes for apparent drift of dielectric constant for microstrip circuits, and high conductor losses observed in measurements, are introduced. Finally, studies are performed for the design of a Ku/Ka-Band shared aperture array. Different approaches for developing dual-band shared apertures

  6. Comparison of Adaptive Antenna Arrays Controlled by Gradient Algorithms

    Directory of Open Access Journals (Sweden)

    Z. Raida

    1994-09-01

    Full Text Available The paper presents the Simple Kalman filter (SKF that has been designed for the control of digital adaptive antenna arrays. The SKF has been applied to the pilot signal system and the steering vector one. The above systems based on the SKF are compared with adaptive antenna arrays controlled by the classical LMS and the Variable Step Size (VSS LMS algorithms and by the pure Kalman filter. It is shown that the pure Kalman filter is the most convenient for the control of the adaptive arrays because it does not require any a priori information about noise statistics and excels in high rate of convergence and low misadjustment. Extremely high computational requirements are drawback of this filter. Hence, if low computational power of signal processors is at the disposal, the SKF is recommended to be used. Computational requirements of the SKF are of the same order as the classical LMS algorithm exhibits. On the other hand, all the important features of the pure Kalman filter are inherited by the SKF. The paper shows that presented Kalman filters can be regarded as special gradient algorithms. That is why they can be compared with the LMS family.

  7. Electrical optimization of the ICH antenna array for ITER

    International Nuclear Information System (INIS)

    The present design of the ITER ICH antenna array comprises two poloidal by four toroidal current elements in each of four ports. Each current element forms a resonant double loop (RDL) with power fed to a pretuned matchpoint on the strap; the matching is accomplished using slow-wave transmission lines as adjustable shorted-stub tuners on other end of the current strap. The power requirement is 12.5 MW per port over the frequency range of 40 endash 70 MHz, with extended operation to 80 MHz desirable. The antenna design optimization process includes (1) strap shaping to minimize strap voltages and rf E-fields along B-field lines and (2) frame/Faraday shield geometry design to improve plasma coupling, wave spectrum directivity, and phase control. For the ignited plasma parameters, the optimized array design delivers full power over the ranges of 40 endash 80 MHz in frequency and 0 degree to 180 degree in phase. The maximum strap voltage is 41 kV and the maximum parallel E-field is 16 kV/cm for the worst case over these ranges. The array directivity for current drive operation is calculated to be close to 80%. copyright 1997 American Institute of Physics

  8. Electrical optimization of the ICH antenna array for ITER

    Science.gov (United States)

    Ryan, P. M.; Swain, D. W.; Carter, M. D.; Taylor, D. J.; Bosia, G.

    1997-04-01

    The present design of the ITER ICH antenna array comprises two poloidal by four toroidal current elements in each of four ports. Each current element forms a resonant double loop (RDL) with power fed to a pretuned matchpoint on the strap; the matching is accomplished using slow-wave transmission lines as adjustable shorted-stub tuners on other end of the current strap. The power requirement is 12.5 MW per port over the frequency range of 40-70 MHz, with extended operation to 80 MHz desirable. The antenna design optimization process includes (1) strap shaping to minimize strap voltages and rf E-fields along B-field lines and (2) frame/Faraday shield geometry design to improve plasma coupling, wave spectrum directivity, and phase control. For the ignited plasma parameters, the optimized array design delivers full power over the ranges of 40-80 MHz in frequency and 0° to 180° in phase. The maximum strap voltage is 41 kV and the maximum parallel E-field is 16 kV/cm for the worst case over these ranges. The array directivity for current drive operation is calculated to be close to 80%.

  9. Beamforming via large and dense antenna arrays above a clutter

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Tsakalaki, Elpiniki; Huang, Howard; Pedersen, Gert Frølund

    2013-01-01

    The paper sheds light on the beamforming (BF) performance of large (potentially unconstrained in size) as well as dense (but physically constrained in size) antenna arrays when equipped with arbitrarily many elements. Two operational modes are investigated: Single-layer BF and multi-layer BF. In...... necessitate multi-layering. In the multi-layer BF mode, the RF coverage is divided into a number of directive non-overlapping sector-beams in a deterministic manner within a multi-user multi-input multi-output (MIMO) system. The optimal number of layers that maximizes the user's sum-rate given a constrained...

  10. SAR processing with stepped chirps and phased array antennas.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-09-01

    Wideband radar signals are problematic for phased array antennas. Wideband radar signals can be generated from series or groups of narrow-band signals centered at different frequencies. An equivalent wideband LFM chirp can be assembled from lesser-bandwidth chirp segments in the data processing. The chirp segments can be transmitted as separate narrow-band pulses, each with their own steering phase operation. This overcomes the problematic dilemma of steering wideband chirps with phase shifters alone, that is, without true time-delay elements.

  11. Secondary Surveillance Radar Antenna

    OpenAIRE

    Schejbal, Vladimír; Bezoušek, Pavel; Pidanič, Jan; Chyba, Milan

    2013-01-01

    This paper deals with a secondary surveillance radar (SSR) array antenna, which is intended for a system combining the secondary surveillance radar antenna and the primary surveillance radar antenna. It describes the patch array elements and the synthesis for the secondary surveillance radar array, considering both elevation and azimuth patterns for sum, difference, and sidelobe-suppression beams, and suspended stripline couplers. The utilization of multilayer techniques allows the connection...

  12. A Novel Receiver Architecture for DBF Antenna Array

    Institute of Scientific and Technical Information of China (English)

    ZHENG Sheng-hua; XU Da-zhuan; JIN Xue-ming

    2007-01-01

    The developments of the high speed analog to digital converters (ADC) and advanced digital signal processors (DSP) make the smart antenna with digital beamforming (DBF)a reality. In conventional M-elements array antenna system, each element has its own receiving channel and ADCs. In this paper, a novel smart antenna receiver with digital beamforming is proposed. The essential idea is to realize the digital beamforming receiver based on bandpass sampling of multiple distinct intermediate frequency (IF) signals. The proposed system reduces receiver hardware from M IF channels and 2M ADCs to one IF channel and one ADC using a heterodyne radio frequency (RF) circuitry and a multiple bandpass sampling digital receiver. In this scheme, the sampling rate of the ADC is much higher than the summation of the M times of the signal bandwidth. The local oscillator produces different local frequency for each RF channel.The receiver architecture is presented in detail, and the simulation of bandpass sampling of multiple signals and digital down conversion to baseband is given. The principle analysis and simulation results indicate the effectiveness of the new proposed receiver.

  13. The Digital Motion Control System for the Submillimeter Array Antennas

    Science.gov (United States)

    Hunter, T. R.; Wilson, R. W.; Kimberk, R.; Leiker, P. S.; Patel, N. A.; Blundell, R.; Christensen, R. D.; Diven, A. R.; Maute, J.; Plante, R. J.; Riddle, P.; Young, K. H.

    2013-09-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error function. Calibration factors and software filters are applied to the tachometer feedback prior to the application of the servo gains in the torque computations. All of these parameters are remotely adjustable in the software. The three layers of the control system monitor each other and are capable of shutting down the system safely if a failure or anomaly occurs. The Unix system continuously relays the antenna status to the central observatory computer via reflective memory. In each antenna, a Palm Vx hand controller displays the complete system status and allows full local control of the drives in an intuitive touchscreen user interface. The hand controller can also be connected outside the cabin, a major convenience during the frequent reconfigurations of the interferometer. Excellent tracking performance ( 0.3‧‧ rms) is achieved with this system. It has been in reliable operation on 8 antennas for over 10 years and has required minimal maintenance.

  14. Antenna Array Structures Effect on Water-Filling Capacity of Indoor NLOS MIMO Channel

    Institute of Scientific and Technical Information of China (English)

    L(U) Jian-gang; L(U) Ying-hua; DU Juan; LI Yun-zhuang; WANG Xu-ying

    2005-01-01

    A 2-D Shooting and Bouncing Ray-tracing method (SBR) is used to analyze the different antenna array structure effect on the water-filling Capacity Complementary Cumulative Distribution Functions (CCDFS) of indoor Non-Line-of-Sight (NLOS) Multiple-Input Multiple-Output (MIMO) channel. The results have shown that in NLOS indoor environment different antenna array structures affect on the CCDFS differently. The CCDFS of MIMO systems with antenna spacing 5λ change slightly with antenna array structures and all approach the in independent and identically distribution (i.i.d.) rayleigh channel water-filling capacity. When antenna spacing decreased to 0.5λ, the capacities of MIMO systems drop also, and change with antenna array structures greatly. The results on outage water-filling capacity also show that there exist a fixed relationship that i.i.d. rayleigh channel capacity is larger than the capacity equipped with linear antenna array which is larger than the capacity equipped with rectangular antenna array and the capacity equipped with circular antenna array.

  15. The DESDynI Synthetic Aperture Radar Array-Fed Reflector Antenna

    Science.gov (United States)

    Chamberlain, Neil; Ghaemi, Hirad; Giersch, Louis; Harcke, Leif; Hodges, Richard; Hoffman, James; Johnson, William; Jordan, Rolando; Khayatian, Behrouz; Rosen, Paul; Sadowy, Gregory; Shaffer, Scott; Shen, Yuhsyen; Veilleux, Louise; Wu, Patrick

    2010-01-01

    DESDynI is a mission being developed by NASA with radar and lidar instruments for Earth-orbit remote sensing. This paper focuses on the design of a largeaperture antenna for the radar instrument. The antenna comprises a deployable reflector antenna and an active switched array of patch elements fed by transmit/ receive modules. The antenna and radar architecture facilitates a new mode of synthetic aperture radar imaging called 'SweepSAR'. A system-level description of the antenna is provided, along with predictions of antenna performance.

  16. Wideband Dual-Polarization Microstrip Patch Antenna Array for Airborne Ice Sounder

    DEFF Research Database (Denmark)

    Vazquez-Roy, Jose Luis; Krozer, Viktor; Dall, Jørgen

    2012-01-01

    We present the design and realization of an antenna array based on cavity-backed microstrip patch antenna elements, with a relative operating bandwidth exceeding 20% at a return-loss level better than 15 dB. The antenna array of four elements did not show any compromise in bandwidth. It exhibited...... sidelobe levels better than 15 dB, with a gain of around 12 dBi. Excellent agreement was achieved between measurements and predictions for the designs of both the single element and the array. This antenna is part of the European Space Agency's airborne polarimetric P-band terrestrial ice sounder....

  17. A wave matrix technique for analysis of lossy antenna array noise

    OpenAIRE

    Tokarsky, Peter L.

    1997-01-01

    A universal technique is proposed for the analysis of the noise temperature of an arbitrary phased antenna array allowing to estimate the contribution of all the sources of internal noises under rigorous taking into account of the mutual coupling between loss radiators. The technique is based on the matrix theory of antenna arrays [1, 2] and noisy microwave multiport circuits theory [3, 4].

  18. Wide-Angle X-Band Antenna Array with Novel Radiating Elements

    Directory of Open Access Journals (Sweden)

    R. Chernobrovkin

    2008-06-01

    Full Text Available An antenna array with wide-angle beam steering is presented in this paper. The antenna consists of dielectrically filled open-ended waveguides with a new type of excitation as individual radiators. The characteristics of the radiator have been analyzed. The novel radiator has a wide beamwidth and the frequency band of around 21%. Following the computational modeling and experimental investigations the characteristics of the antenna array for scan angles up to 50° are discussed.

  19. Direction of Arrival Estimation with Arbitrary Virtual Antenna Arrays using Low Cost Inertial Measurement Units

    OpenAIRE

    Yaqoob, Muhammad Atif; Tufvesson, Fredrik; Mannesson, Anders; Bernhardsson, Bo

    2013-01-01

    In this paper, we have investigated the use of virtual antenna arrays at the receiver to do single antenna direction-of-arrival estimation. The array coordinates are obtained by doing simple dead reckoning using acceleration and angular speed measurements from a low cost micro-electro-mechanical system inertial measurement unit (IMU). The proposed solution requires no extra hardware in terms of receiver chains and antenna elements. Direction-of-arrival estimation results are obtained using a ...

  20. Design and Experiment of Multi-resolution Composite Digital Array Antenna

    Directory of Open Access Journals (Sweden)

    Tang Yue

    2016-06-01

    Full Text Available Because a sparse array has the advantages of a simplified structure and reduced cost in a radar system, radar technology based on the sparse array has gained widespread attention. To take advantage of the sparse array, in this paper, we designed a Multi-Resolution Composite digital Array antenna (MRCA, and then used it in single-target and multi-target detection experiments. Using the same number of array elements, our experimental results demonstrate that the MRCA can obtain a narrower main lobe and a lower side lobe, enhances the direction of the array antenna, and improves the angular resolution compared with the uniform linear array.

  1. Conformal Patch Antenna Arrays Design for Onboard Ship Deployment Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Stelios A. Mitilineos

    2013-01-01

    Full Text Available Conformal antennas and antenna arrays (arrays have become necessary for vehicular communications where a high degree of aerodynamic drag reduction is needed, like in avionics and ships. However, the necessity to conform to a predefined shape (e.g., of an aircraft’s nose directly affects antenna performance since it imposes strict constraints to the antenna array’s shape, element spacing, relative signal phase, and so forth. Thereupon, it is necessary to investigate counterintuitive and arbitrary antenna shapes in order to compensate for these constraints. Since there does not exist any available theoretical frame for designing and developing arbitrary-shape antennas in a straightforward manner, we have developed a platform combining a genetic algorithm-based design, optimization suite, and an electromagnetic simulator for designing patch antennas with a shape that is not a priori known (the genetic algorithm optimizes the shape of the patch antenna. The proposed platform is further enhanced by the ability to design and optimize antenna arrays and is intended to be used for the design of a series of antennas including conformal antennas for shipping applications. The flexibility and performance of the proposed platform are demonstrated herein via the design of a high-performance GPS patch antenna.

  2. Antenna coupled detectors for 2D staring focal plane arrays

    Science.gov (United States)

    Gritz, Michael A.; Kolasa, Borys; Lail, Brian; Burkholder, Robert; Chen, Leonard

    2013-06-01

    Millimeter-wave (mmW)/sub-mmW/THz region of the electro-magnetic spectrum enables imaging thru clothing and other obscurants such as fog, clouds, smoke, sand, and dust. Therefore considerable interest exists in developing low cost millimeter-wave imaging (MMWI) systems. Previous MMWI systems have evolved from crude mechanically scanned, single element receiver systems into very complex multiple receiver camera systems. Initial systems required many expensive mmW integrated-circuit low-noise amplifiers. In order to reduce the cost and complexity of the existing systems, attempts have been made to develop new mmW imaging sensors employing direct detection arrays. In this paper, we report on Raytheon's recent development of a unique focal plane array technology, which operates broadly from the mmW through the sub-mmW/THz region. Raytheon's innovative nano-antenna based detector enables low cost production of 2D staring mmW focal plane arrays (mmW FPA), which not only have equivalent sensitivity and performance to existing MMWI systems, but require no mechanical scanning.

  3. A Stacked Microstrip Antenna Array with Fractal Patches

    Directory of Open Access Journals (Sweden)

    Xueyao Ren

    2014-01-01

    Full Text Available A novel microstrip antenna array, which utilizes Giuseppe Peano fractal shaped patches as its radiation elements and adopts a two-layer stacked structure for achieving both wideband and high-gain properties, is proposed. Parametric study estimates that the proposed antenna’s size can be arbitrarily adjusted by changing the fractal proportion while high aperture efficiency is maintained. Two prototypes with 2 × 2 and 4 × 4 fractal patches, respectively, on each layer are designed, fabricated, and measured. Both simulation and measurement results demonstrate that the proposed antenna possesses encouraging performances of wideband, high directivity, and high aperture efficiency simultaneously; for example, for the two prototypes, their S11<-10 dB impedance bandwidths are 23.49% and 18.49%, respectively; at the working frequency of 5.8 GHz, their directivities are 12.2 dBi and 18.2 dBi, and their corresponding aperture efficiencies are up to 91.0% and 90.5%, respectively.

  4. Improvement on a 2 × 2 Elements High-Gain Circularly Polarized Antenna Array

    Directory of Open Access Journals (Sweden)

    C. Liu

    2015-01-01

    Full Text Available A novel antipodal Vivaldi antenna with tapering serrated structure at the edges is proposed. Compared with traditional Vivaldi antennas without serrated structure, the gain of the designed antenna is significantly improved in the desired frequency band (4.5–7.5 GHz. In addition, a 2 × 2 Vivaldi antenna array with an orthorhombic structure is designed and fabricated to achieve a circular polarization (CP characteristic. With this configuration, the 3 dB axial ratio bandwidth of the array reaches about 42% with respect to the center frequency of 6 GHz and a high gain is achieved as well. The novel Vivaldi antenna and CP antenna array both have ultrawide band (UWB and high-gain characteristics, which may be applied to the field of commercial communication, remote sensing, and so forth.

  5. Methods of Signal Processing for Adaptive Antenna Arrays

    CERN Document Server

    Titarenko, Larysa

    2013-01-01

    So far there does not exist any theory of adaptive spatial signal processing (ASSP) for signals with uncertain parameters. This monograph is devoted to the development of this theory, which is very important in connection with wide spreading of telecommunications and radio links in the modern society. This theory can be applied for the development of effective radio communications. In the book some original approaches are proposed targeting the development of effective algorithms of ASSP with not exactly known parameters. They include both probabilistic and deterministic approaches for synthesis of robust algorithms of ASSP. The solution of problems also can be reduced to the construction of some operators for the Banach space which is presented in the book.  “Methods of Signal Processing for Adaptive Antenna Arrays” targets professionals, students and PhD students in the area of telecommunications and should be useful for everybody connected with the new information technologies.

  6. High Gain and High Directive of Antenna Arrays Utilizing Dielectric Layer on Bismuth Titanate Ceramics

    Directory of Open Access Journals (Sweden)

    F. H. Wee

    2012-01-01

    Full Text Available A high gain and high directive microstrip patch array antenna formed from dielectric layer stacked on bismuth titanate (BiT ceramics have been investigated, fabricated, and measured. The antennas are designed and constructed with a combination of two-, four-, and six-BiT elements in an array form application on microwave substrate. For gain and directivity enhancement, a layer of dielectric was stacked on the BiT antenna array. We measured the gain and directivity of BiT array antennas with and without the dielectric layer and found that the gain of BiT array antenna with the dielectric layer was enhanced by about 1.4 dBi of directivity and 1.3 dB of gain over the one without the dielectric layer at 2.3 GHz. The impedance bandwidth of the BiT array antenna both with and without the dielectric layer is about 500 MHz and 350 MHz, respectively, which is suitable for the application of the WiMAX 2.3 GHz system. The utilization of BiT ceramics that covers about 90% of antenna led to high radiation efficiency, and small-size antennas were produced. In order to validate the proposed design, theoretical and measured results are provided and discussed.

  7. Design and Implementation of Series Micro Strip Patch Antenna Array for Wireless Communication

    Directory of Open Access Journals (Sweden)

    Priya Upadhyay

    2012-09-01

    Full Text Available Micro Strip Antenna Array has beenproposed with high efficiency for wirelesscommunication. Micro strip antenna arrays arewidely used in various applications like in wirelesscommunication system, satellite communication,Radar systems, Global positioning systems, RadioFrequency Identification (RFID, Worldwideinteroperability for microwave access (WiMax,Rectenna applications, Telemedicine applications,Medicinal applications of patch. In this articleseries micro strip square patch antenna array isdesigned due to its wide band and wide scanproperties which can give more information at highdata rate. The proposed antenna consist of astraight feeding micro strip line and squareradiating elements connected directly to the microstrip line at their corners without dividers andimpedance transformers in order to realize lowerfeeding line loss. In this paper, the model of microstrip series antenna array is designed and analyzedusing the HFSS Software. The parametric study ofthe antenna characteristics has been done to knowhow the micro strip series antenna array meets thewireless properties for geometric parameters. Thispaper micro strip series antenna array will bedesigned at 2.4 GHz (S- band frequency

  8. Analysis of Circularly Polarized Hemispheroidal Dielectric Resonator Antenna Phased Arrays Using the Method of Auxiliary Sources

    OpenAIRE

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    The method of auxiliary sources is employed to model and analyze probe-fed hemispheroidal dielectric resonator antennas and arrays. Circularly polarized antenna elements of different designs are analyzed, and impedance bandwidths of up to 14.7% are achieved. Selected element designs are subsequently employed in a seven-element phased array. The array performance is analyzed with respect to scan loss and main beam directivity as a function of scan angle and frequency, and the influence of elem...

  9. Improvement on a 2 × 2 Elements High-Gain Circularly Polarized Antenna Array

    OpenAIRE

    Liu, C; Yan, A; Yu, C.; Xu, T.

    2015-01-01

    A novel antipodal Vivaldi antenna with tapering serrated structure at the edges is proposed. Compared with traditional Vivaldi antennas without serrated structure, the gain of the designed antenna is significantly improved in the desired frequency band (4.5–7.5 GHz). In addition, a 2 × 2 Vivaldi antenna array with an orthorhombic structure is designed and fabricated to achieve a circular polarization (CP) characteristic. With this configuration, the 3 dB axial ratio bandwidth of the array rea...

  10. Reconfigurable Plasma Antenna Array by Using Fluorescent Tube for Wi-Fi Application

    Directory of Open Access Journals (Sweden)

    H. Ja’afar

    2016-06-01

    Full Text Available This paper presents a new design of reconfigurable plasma antenna array using commercial fluorescent tube. A round shape reconfigurable plasma antenna array is proposed to collimate beam radiated by an omnidirectional antenna (monopole antenna operates at 2.4GHz in particular direction. The antenna design is consisted of monopole antenna located at the center of circular aluminum ground. The monopole antenna is surrounded by a cylindrical shell of conducting plasma. The plasma shield consists of 12 commercial fluorescent tubes aligned in series containing a mixture of Argon gas and mercury vapor which upon electrification forms plasma columns. The plasma behaves as a conductor and acts as a reflector in radiation, in the condition where plasma frequency,ωp is higher than operating frequency. From this concepts, when all plasma elements are activated or switched to ON, the radiation signal from monopole antenna will trapped inside the plasma blanket and meanwhile when one or more plasma elements is deactivated (switched OFF, the radiation from monopole antenna will escape. This antenna has the capability to change its patterns with beam direction at 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300° and 330° at frequency 2.4 GHz. The proposed antenna has been successfully fabricated and measured with conclusive results.

  11. 5x1 Linear Antenna Array for 60 GHz Beam Steering Applications

    OpenAIRE

    Kyrö, Mikko; Titz, Diane; Kolmonen, Veli-Matti; Ranvier, Sylvain; Pons, Patrick; Luxey, Cyril; Vainikainen, Pertti

    2011-01-01

    This paper presents a design process and simulation results of a 5 x 1 linear antenna array with phase shifters for 60 GHz beam steering applications. The antenna array has been designed using a membrane process in order to achieve high radiation efficiency and good radiation characteristics. The same process can be used to manufacture Micro-Electro-Mechanical Systems (MEMS) switches and phase shifters. The maximum gain of the developed antenna array is 9.0 dBi and the radiation efficiency is...

  12. An Optimal Beamforming Algorithm for Phased-Array Antennas Used in Multi-Beam Spaceborne Radiometers

    DEFF Research Database (Denmark)

    Iupikov, O. A.; Ivashina, M. V.; Pontoppidan, K.; Cappellin, C.; Skou, Niels; Søbjærg, Sten Schmidl; Ihle, A.; Hartmann, D.; 't Klooster, K. v.; Nielsen, P. H.

    2015-01-01

    Strict requirements for future spaceborne ocean missions using multi-beam radiometers call for new antenna technologies, such as digital beamforming phased arrays. In this paper, we present an optimal beamforming algorithm for phased-array antenna systems designed to operate as focal plane arrays...... a FPA feeding a torus reflector antenna (designed under the contract with the European Space Agency) and tested for multiple beams. The results demonstrate an improved performance in terms of the optimized beam characteristics, yielding much higher spatial and radiometric resolution as well as much...

  13. Mechanical Development of a Very Non-Standard Patch Array Antenna for Extreme Environments

    Science.gov (United States)

    Hughes, Richard; Chamberlain, Neil; Jakoboski, Julie; Petkov, Mihail

    2012-01-01

    This paper describes the mechanical development of patch antenna arrays for the Juno mission. The patch arrays are part of a six-frequency microwave radiometer instrument that will be used to measure thermal emissions from Jupiter. The very harsh environmental conditions in Jupiter orbit, as well as a demanding launch environment, resulted in a design that departs radically from conventional printed circuit patch antennas. The paper discusses the development and qualification of the Juno patch array antennas, with emphasis on the materials approach that was devised to mitigate the effects of electron charging in Jupiter orbit.

  14. A Switchable 3D-Coverage Phased Array Antenna Package for 5G Mobile Terminals

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Zhang, Shuai;

    2016-01-01

    This manuscript proposes a new design of a millimeter-wave (mm-Wave) array antenna package with beam steering characteristic for the fifth generation (5G) mobile applications. In order to achieve a broad 3D scanning coverage of the space with high-gain beams, three identical sub arrays of patch...... antennas have been compactly arranged along the edge region of the mobile phone PCB to form the antenna package. By switching the feeding to one of the sub arrays, the desired direction of coverage can be achieved. The proposed design has >10 dB gain in the upper spherical space, good directivity and...

  15. Corporate-Feed Multilayer Bow-Tie Antenna Array Design Using a Simple Transmission Line Model

    OpenAIRE

    Didouh, S.; Abri, M.; F. T. Bendimerad

    2012-01-01

    A transmission line model is used to design corporate-fed multilayered bow-tie antennas arrays; the simulated antennas arrays are designed to resonate at the frequencies 2.4 GHz, 5 GHz, and 8 GHz corresponding to RFID, WIFI, and radars applications. The contribution of this paper consists of modeling multilayer bow-tie antenna array fed through an aperture using transmission line model. The transmission line model is simple and precise and allows taking into account the whole geometrical, ele...

  16. The Mutual Interaction effects between Array Antenna Parameters and Receiving Signals Bandwidth

    Directory of Open Access Journals (Sweden)

    Shahad D. Sateaa

    2014-03-01

    Full Text Available The presence of a single complex adaptive weight in each element channel of an adaptive array antenna is sufficient for processing of narrowband signals. The ability of an adaptive array antenna to null interference deteriorates rapidly as the interference bandwidth increases. The performance of narrowband adaptive array antenna with LMCV Beamforming algorithm is examined. The interaction effects between received signal angle of arrival and array parameters like the interelement spacing and the number of array element and the received signal bandwidth were studied. The output Signal to Interference plus Noise Ratio (SINR and Interference to Noise Ratio (INR are used as performance parameters for evaluation of these effects. It is found that the amount of degradation in the output SINR is increased significantly with the increase of array interelement spacing, number of array elements and when the angle of arrival of received signals are closet to end fire.

  17. Yagi-Uda optical antenna array collimated laser based on surface plasmons

    Science.gov (United States)

    Ma, Long; Lin, Jie; Ma, Yuan; Liu, Bin; Tan, Jiubin; Jin, Peng

    2016-06-01

    The divergence and directivity of a laser with a periodic Yagi-Uda optical antenna array modulated surface are investigated by finite element method. The nanoparticle optical antenna arrays are optimized to achieve the high directivity and the small divergence by using of Helmholtz's reciprocity theorem. When the nanoparticle antenna replaced by a Yagi-Uda antenna with same size, the directivity and the signal-to-noise ratio of the modulated laser beam are notably enhanced. The main reason is that the directors of the Yagi-Uda antennas induce more energy to propagate towards the antenna transmitting direction. The results can provide valuable guidelines in designing collimated laser, which can be widely applied in the field of biologic detection, spatial optical communication and optical measurement.

  18. DESIGN OF HYBRID COUPLER CONNECTED SQUARE ARRAY PATCH ANTENNA FOR Wi-Fi APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. Sahaya Anselin Nisha

    2012-01-01

    Full Text Available Microstrip patch antennas being popular because of light weight, low volume, thin profile configuration which can be made conformal. Wireless communication systems applications circular polarization antenna is placing vital role. In this study we introduce a new technique to produce circular polarization. Hybrid coupler is directly connected to microstrip antenna to get circular polarization. Also gain is further increased by introducing antenna array technique. Each square in array having length of 4.6mm patch is having thickness of 0.381mm and the dielectric material used FR4. The designed antenna having high gain of 6.26dB and directivity of 5.11dB at the resonant frequency of 3.7GHz. Simulation results shows that the designed antenna characteristic is suitable for Wi-Fi applications.

  19. Circular patch microstrip array antenna on NiCoAl ferrite substrate in C-band

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dheeraj, E-mail: kdheeraj_7@yahoo.co.i [Department Of Physics, Agra College, Agra 282005 (India); Pourush, P.K.S. [Department Of Physics, Agra College, Agra 282005 (India)

    2010-05-15

    The problem of a 4x4 circular disc array antenna (CDAA) printed on a uniaxially anisotropic ferrite (NiCoAl) substrate is treated. The effect of anisotropy on the resonant frequency of the antenna is investigated. Radiation and scattering characteristics of the antenna with normal magnetic bias field to the direction of wave propagation in the plane of ferrite are described. Calculated result for the radar cross section (RCS) of antenna presented, and it is shown that the peaks in the RCS can be moved with respect to angle of incidence by changing the magnetic bias field. This effect offers a way of minimizing the radar visibility of microstrip antennas and arrays. Results are obtained from cavity modal solutions for a circular patch antenna at its TM{sub 11} mode.

  20. Directional antenna array (DAA) for communications, control, and data link protection

    Science.gov (United States)

    Molchanov, Pavlo A.; Contarino, Vincent M.

    2013-06-01

    A next generation of Smart antennas with point-to-point communication and jam, spoof protection capability by verification of spatial position is offered. A directional antenna array (DAA) with narrow irradiation beam provides counter terrorism protection for communications, data link, control and GPS. Communications are "invisible" to guided missiles because of 20 dB smaller irradiation outside the beam and spatial separation. This solution can be implemented with current technology. Directional antennas have higher gain and can be multi-frequency or have wide frequency band in contrast to phase antenna arrays. This multi-directional antenna array provides a multi-functional communication network and simultaneously can be used for command control, data link and GPS.

  1. A Polarization Reconfigurable Aperture-Coupled Microstrip Antenna and Its Binary Array for MIMO

    Science.gov (United States)

    Zhong, Lei; Hong, Jin-Song; Zhou, Hong-Cheng

    2016-03-01

    In the paper, a singly fed circular patch antenna with polarization diversity is proposed, and its binary array for MIMO application is explored as well. The air substrate and aperture-coupled feed structure are adopted to increase bandwidth and simplify the bias circuit of PIN diodes. By controlling the states of four PIN diodes on the patch, the proposed antenna can produce linear polarization (LP), left- or right-hand circular polarization (LHCP or RHCP). For each polarization sense, the antenna exhibits wide impedance bandwidth, high gain and low cross-polarization. Two antennas are orthogonally placed to form a binary array for MIMO application, which has high isolation and low envelope correlation. The antenna and its array have advantages of simple biasing network, easy fabrication and adjustment, which can be widely applied in wireless communication systems.

  2. FAILURE CORRECTION OF LINEAR ARRAY ANTENNA WITH MULTIPLE NULL PLACEMENT USING CUCKOO SEARCH ALGORITHM

    OpenAIRE

    Muralidaran, R.; A. Vallavaraj; Hemant Patidar; Mahanti, G. K.

    2014-01-01

    The influence of evolutionary algorithms enhanced its scope of getting its existence in almost every complex optimization problems. In this paper, cuckoo search algorithm, an algorithm based on the brood parasite behavior along with Levy weights has been proposed for the radiation pattern correction of a linear array of isotropic antennas with uniform spacing when failed with more than one antenna element. Even though deterioration produced by the failure of antenna elements results in variou...

  3. Array Antennas Based Joint Beamforming for IEEE 802.11n Wi-Fi

    Directory of Open Access Journals (Sweden)

    Cheng Guo

    2015-09-01

    Full Text Available In order to achieve array gain and spatial diversity or multiplexing gain simultaneously, a novel joint beamforming based on MIMO and array antenna techniques, referred to as J-BF, is proposed for the LTE and Wifi downlink. Array gain is achieved from array antenna based beamforming, referred to as AA-BF. Spatial diversity and multiplexing gains are achieved from MIMO based beamforming, referred to as MIMO-BF. To implement J-BF, i.e., joint AA-BF and MIMO-BF, an access point (AP is equipped with separate array antennas. Before sending any data-frame in the J-BF mode, firstly, based on the estimated omni-directional CSI, the directional beam can be formed by the array antenna, and the array gain is achieved. Secondly, based on the estimated directional CSI, MIMO-BF is implemented to achieve the spatial diversity or multiplexing gain. More importantly, the J-BF algorithm maintains compatibility with 802.11n and there is not any change in terminals. Simulation results show that the proposed scheme can support the joint AA-BF and MIMO-BF effectively and provide much higher array gain or spatial gains than the traditional MIMO or array antenna respectively.

  4. Analysis of Circularly Polarized Hemispheroidal Dielectric Resonator Antenna Phased Arrays Using the Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    The method of auxiliary sources is employed to model and analyze probe-fed hemispheroidal dielectric resonator antennas and arrays. Circularly polarized antenna elements of different designs are analyzed, and impedance bandwidths of up to 14.7% are achieved. Selected element designs are...

  5. A 28 GHz FR-4 Compatible Phased Array Antenna for 5G Mobile Phone Applications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    The design of a 28 GHz phased array antenna for future fifth generation (5G) mobile-phone applications has been presented in this paper. The proposed antenna can be implemented using low cost FR-4 substrates, while maintaining good performance in terms of gain and efficiency. This is achieved by...

  6. A Low Cost, Electronically Scanned Array (ESA) Antenna Technology for Aviation Hazard Detection and Avoidance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will investigate the feasibility of utilizing ThinKom's low cost electronically scanned array (ESA) antenna concepts to enable affordable...

  7. Design of a Compact Wideband Antenna Array for Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    J. Puskely

    2013-12-01

    Full Text Available In the paper, wideband antenna arrays aimed at microwave imaging applications and SAR applications operating at Ka band were designed. The antenna array feeding network is realized by a low-loss SIW technology. Moreover, we have replaced the large feed network comprised of various T and Y junctions by a simple broadband network of compact size to more reduce losses in the substrate integrated waveguide and also save space on the PCB. The designed power 8-way divider is complemented by a wideband substrate integrated waveguide to a grounded coplanar waveguide transition and directly connected to the antenna elements. The measured results of antenna array are consistent with our simulation. Obtained results of the developed array demonstrated improvement compared to previously developed binary feed networks with microstrip or SIW splitters.

  8. Research on Motion Compensation for Airborne Forward Looking Synthetic Aperture Radar with Linear Array Antennas

    Directory of Open Access Journals (Sweden)

    Zhang Ying-jie

    2013-06-01

    Full Text Available Combined with Frequency-Modulated Continuous-Wave (FMCW technology, airborne forward-looking Synthetic Aperture Radar (SAR with linear array antennas can obtain the image in front of the aircraft and also have the advantages of FMCW radar such as small size and lightweight. Moreover, it is suitable to be installed on platform like helicopter and small unmanned aerial vehicle. Motion compensation for forward-looking SAR with linear array antennas is one of the key problems to obtain the image in front of the aircraft in practice. This paper analyses the influence of motion error in aircraft on echo model based on the geometry of forward looking SAR with linear array antennas, and proposes a motion compensation scheme. Moreover, the compensation scheme is applicable to an improved frequency scaling algorithm (FSA for FMCW forward looking SAR with linear array antennas. Finally, the compensation scheme is verified with the simulation.

  9. Dual Polarization Stacked Microstrip Patch Antenna Array With Very Low Cross-Polarization

    DEFF Research Database (Denmark)

    Granholm, Johan; Woelders, Kim

    2001-01-01

    This paper describes the development and performance of a wideband dual linear polarization microstrip antenna array used in the Danish high-resolution airborne multifrequency polarimetric synthetic aperture radar, EMISAR. The antenna was designed for an operating frequency of 1.25 GHz±50 MHz and...... was built as an array of 8×2 probe-fed stacked microstrip patches. The feeding network is constructed in microstrip and is capable of handling 6 kW of peak input-power at an altitude of 45000 ft (unpressurized). The impedance bandwidth (return loss better than -14 dB) of the antenna is 10%, the...... isolation between the horizontal and the vertical ports of the array is 50 dB and the cross-polarization suppression is 40 dB. A new design principle for simultaneously achieving very low cross-polarization and low side lobes in dual linear polarization antenna arrays has been applied...

  10. Highly Integrated, Reconfigurable, Large-Area, Flexible Radar Antenna Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Highly-integrated, reconfigurable radar antenna arrays fabricated on flexible substrates offer high functionality in a portable package that can be rolled up and...

  11. 8×8 Planar Phased Array Antenna with High Efficiency and Insensitivity Properties for 5G Mobile Base Stations

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2016-01-01

    An insensitive planar phased array antenna with high efficiency function for 5G applications is introduced in this study. 64-elements of compact slot-loop antenna elements have been used to form the 8×8 planar array. The antenna is designed on a low cost FR4 substrate and has good performance in...

  12. The Digital Motion Control System for the Submillimeter Array Antennas

    CERN Document Server

    Hunter, T R; Kimberk, R; Leiker, P S; Patel, N A; Blundell, R; Christensen, R D; Diven, A R; Maute, J; Plante, R J; Riddle, P; Young, K H

    2013-01-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter diameter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error functi...

  13. Slow and fast light in SOA-EA structures for phased-array antennas

    DEFF Research Database (Denmark)

    Sales, S.; Öhman, Filip; Bermejo, A.;

    We present an SOA-EA structure for controlling the phase and amplitude of optically fed phased-array antennas. Phase shifts of 40 degrees are obtained through slow and fast light effects by changing only the reverse voltage.......We present an SOA-EA structure for controlling the phase and amplitude of optically fed phased-array antennas. Phase shifts of 40 degrees are obtained through slow and fast light effects by changing only the reverse voltage....

  14. A Low-Profile Cavity-Backed Dual-Polarized Spiral Antenna Array

    OpenAIRE

    Serhir, Mohammed; Guinvarc'H, Régis

    2013-01-01

    International audience A low-profile cavity-backed dual-polarized printed spiral antenna array is presented. This spiral array is composed of four center-fed Archimedean spiral antennas printed on FR4 substrate backed by a low-profile cavity without absorbing material. The dual polarization is generated using monopolarized spirals in an alternating configuration right-hand circularly polarized (RHCP) and left-hand circularly polarized (LHCP). These spirals are connected allowing the curren...

  15. Multiobjective Optimization Method for Multichannel Microwave Components of Active Phased Array Antenna

    OpenAIRE

    Wang, Lu; Wang, Zhihai; Wang, Congsi; Li, Guozhou; Yin, Lei

    2016-01-01

    Multichannel microwave components are widely used and the active phased array antenna is a typical representative. The high power generated from T/R modules in active phased array antenna (APAA) leads to the degradation of its electrical performances, which seriously restricts the development of high-performance APAA. Therefore, to meet the demand of thermal design for APAA, a multiobjective optimization design model of cold plate is proposed. Furthermore, in order to achieve temperature unif...

  16. Beam-Steerable Microstrip-Fed Bow-Tie Antenna Array for Fifth Generation Cellular Communications

    OpenAIRE

    Ojaroudiparchin, Naser; Shen, Ming; Gert F. Pedersen

    2016-01-01

    The design and performance of mm-wave phased array antenna for 5G mobile broadband communication systems has been provided in this manuscript. The antenna is designed on a N9000 PTFE substrate with 0.787 mm thickness and 2.2 dielectric constant and 65×130 mm2 overall dimension. Eight elements of bow-tie antennas have been used at the top-edge region of mobile phone PCB. The antenna elements fed by microstrip lines are designed to operate at 17 GHz. The simulated results give good performances...

  17. Bi-Band Bow-Tie Antennas Array Design Using a Simple Equivalent Transmission Line Model

    Directory of Open Access Journals (Sweden)

    M. Abri

    2012-08-01

    Full Text Available In this paper we propose a simple equivalent and accurate transmission line model for bi-band bow-tie antennas array design over a band of frequencies for satellite communications. This model uses the resistance of a square element that appears at the edges of the antenna (radiating slots. To test this model, two antennas array were simulated and results were compared with those obtained by a rigorous method (moment’s method of the simulator ADS/Momentum. Using this transmission line approach the resonant frequency, return loss, VSWR, reflected phase, input impedance can be determined simultaneously. The results confirm the validity of the proposed model.

  18. Bi-Band Bow-Tie Antennas Array Design Using a Simple Equivalent Transmission Line Model

    OpenAIRE

    Abri, M.; H. Abri Badaoui; Dib, H; A.S.E. Gharnaout

    2012-01-01

    In this paper we propose a simple equivalent and accurate transmission line model for bi-band bow-tie antennas array design over a band of frequencies for satellite communications. This model uses the resistance of a square element that appears at the edges of the antenna (radiating slots). To test this model, two antennas array were simulated and results were compared with those obtained by a rigorous method (moment’s method) of the simulator ADS/Momentum. Using this transmission line appro...

  19. Near-Field Focusing Dielectric Resonator Antenna Array for Fixed RFID Readers

    Directory of Open Access Journals (Sweden)

    Saber H. Zainud-Deen

    2012-11-01

    Full Text Available The design of a NF‐ focused DRA phased array antenna is implemented for fixed RFID reader applications at 5.8 GHz. The radiated field is focused in the near‐zone of the array aperture. Numerical investigations on the radiation characteristics of the NFfocused array as well as uniform phase array are presented to demonstrate its feasibility for RFID real applications.

  20. New method for the time calibration of an interferometric radio antenna array

    CERN Document Server

    Schröder, F G; Bähren, L; Blümer, J; Bozdog, H; Falcke, H; Haungs, A; Horneffer, A; Huege, T; Isar, P G; Krömer, O; Nehls, S; 10.1016/j.nima.2010.01.072

    2010-01-01

    Digital radio antenna arrays, like LOPES (LOFAR PrototypE Station), detect high-energy cosmic rays via the radio emission from atmospheric extensive air showers. LOPES is an array of dipole antennas placed within and triggered by the KASCADE-Grande experiment on site of the Karlsruhe Institute of Technology, Germany. The antennas are digitally combined to build a radio interferometer by forming a beam into the air shower arrival direction which allows measurements even at low signal-to-noise ratios in individual antennas. This technique requires a precise time calibration. A combination of several calibration steps is used to achieve the necessary timing accuracy of about 1 ns. The group delays of the setup are measured, the frequency dependence of these delays (dispersion) is corrected in the subsequent data analysis, and variations of the delays with time are monitored. We use a transmitting reference antenna, a beacon, which continuously emits sine waves at known frequencies. Variations of the relative del...

  1. A method of measurement of directivity characteristics of antenna’s elements for digital antenna array in conditions of jammers

    OpenAIRE

    Slyusar, V. I.; Voloshko, S. V.

    2009-01-01

    A new two-stage digital processing of OFDM signals for measurement of directivity characteristics (DC) of antenna elements in digital antenna array (DAA) with test sources is described in this report.

  2. Measuring Phased-Array Antenna Beampatterns with High Dynamic Range for the Murchison Widefield Array using 137 MHz ORBCOMM Satellites

    CERN Document Server

    Neben, A R; Hewitt, J N; Bernardi, G; Bowman, J D; Briggs, F; Cappallo, R J; Deshpande, A A; Goeke, R; Greenhill, L J; Hazelton, B J; Johnston-Hollitt, M; Kaplan, D L; Lonsdale, C J; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Ord, S M; Prabu, T; Shankar, N Udaya; Srivani, K S; Subrahmanyan, R; Tingay, S J; Wayth, R B; Webster, R L; Williams, A; Williams, C L

    2015-01-01

    Detection of the fluctuations in 21 cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibration and image quality, both of which necessitate accurate primary beam models. The Murchison Widefield Array (MWA) uses phased array antenna elements which maximize collecting area at the cost of complexity. To quantify their performance, we have developed a novel beam measurement system using the 137 MHz ORBCOMM satellite constellation and a reference dipole antenna. Using power ratio measurements, we measure the {\\it in situ} beampattern of the MWA antenna tile relative to that of the reference antenna, canceling the variation of satellite flux or polarization with time. We employ angular averaging to mitigate multipath effects (ground scattering), and assess environmental systematics with a null experiment in which the MWA tile is replaced with a second reference dipole. We achieve beam measurements over 30 dB dynamic range in beam...

  3. Implementation of an Antenna Array Signal Processing Breadboard for the Deep Space Network

    Science.gov (United States)

    Navarro, Robert

    2006-01-01

    The Deep Space Network Large Array will replace/augment 34 and 70 meter antenna assets. The array will mainly be used to support NASA's deep space telemetry, radio science, and navigation requirements. The array project will deploy three complexes in the western U.S., Australia, and European longitude each with 400 12m downlink antennas and a DSN central facility at JPL. THis facility will remotely conduct all real-time monitor and control for the network. Signal processing objectives include: provide a means to evaluate the performance of the Breadboard Array's antenna subsystem; design and build prototype hardware; demonstrate and evaluate proposed signal processing techniques; and gain experience with various technologies that may be used in the Large Array. Results are summarized..

  4. A hybrid antenna array design for 3-d direction of arrival estimation.

    Directory of Open Access Journals (Sweden)

    Najam-Us Saqib

    Full Text Available A 3-D beam scanning antenna array design is proposed that gives a whole 3-D spherical coverage and also suitable for various radar and body-worn devices in the Body Area Networks applications. The Array Factor (AF of the proposed antenna is derived and its various parameters like directivity, Half Power Beam Width (HPBW and Side Lobe Level (SLL are calculated by varying the size of the proposed antenna array. Simulations were carried out in MATLAB 2012b. The radiators are considered isotropic and hence mutual coupling effects are ignored. The proposed array shows a considerable improvement against the existing cylindrical and coaxial cylindrical arrays in terms of 3-D scanning, size, directivity, HPBW and SLL.

  5. A hybrid antenna array design for 3-d direction of arrival estimation.

    Science.gov (United States)

    Saqib, Najam-Us; Khan, Imdad

    2015-01-01

    A 3-D beam scanning antenna array design is proposed that gives a whole 3-D spherical coverage and also suitable for various radar and body-worn devices in the Body Area Networks applications. The Array Factor (AF) of the proposed antenna is derived and its various parameters like directivity, Half Power Beam Width (HPBW) and Side Lobe Level (SLL) are calculated by varying the size of the proposed antenna array. Simulations were carried out in MATLAB 2012b. The radiators are considered isotropic and hence mutual coupling effects are ignored. The proposed array shows a considerable improvement against the existing cylindrical and coaxial cylindrical arrays in terms of 3-D scanning, size, directivity, HPBW and SLL. PMID:25790103

  6. Multiple Interference Cancellation Performance for GPS Receivers with Dual-Polarized Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Moeness G. Amin

    2008-11-01

    Full Text Available This paper examines the interference cancellation performance in global positioning system (GPS receivers equipped with dual-polarized antenna arrays. In dense jamming environment, different types of interferers can be mitigated by the dual-polarized antennas, either acting individually or in conjunction with other receiver antennas. We apply minimum variance distorntionless response (MVDR method to a uniform circular dual-polarized antenna array. The MVDR beamformer is constructed for each satellite. Analysis of the eigenstructures of the covariance matrix and the corresponding weight vector polarization characteristics are provided. Depending on the number of jammers and jammer polarizations, the array chooses to expend its degrees of freedom to counter the jammer polarization or/and use phase coherence to form jammer spatial nulls. Results of interference cancellations demonstrate that applying multiple MVDR beamformers, each for one satellite, has a superior cancellation performance compared to using only one MVDR beamformer for all satellites in the field of view.

  7. Upgrade of 2-D antenna array for microwave imaging reflectometry and ECE imaging

    International Nuclear Information System (INIS)

    Two types of 2-D Microwave Imaging, Microwave Imaging Reflectometry (MIR) and Electron Cyclotron Emission Imaging (ECEI) have been developed for the Large Helical Device (LHD). These are methods of 2-D / 3-D imaging diagnostics on electron density fluctuations and electron temperature for the investigation of micro-turbulence and magneto-hydrodynamic instabilities in magnetically confined plasmas. 1-D horn antenna array was developed for a 2-D receiver antenna array of the MIR (freq. range: 50 - 75 GHz). This antenna is also able to be used for a receiver of the ECEI (freq. range: 95 - 110 GHz). To apply the ECEI receiver, and to extend the measurement range of these diagnostics, the 1-D horn antenna array was upgraded. (author)

  8. Theoretical power deposition of an interstitial microwave antenna array at various frequencies

    International Nuclear Information System (INIS)

    The theoretical pattern of specific absorption rate (SAR) has been calculated within an array of four interstitial antennas driven in phase at 300, 400, 500, 600, 700, 800, and 915 MHz. The antennas are constructed of 0.67mm OD coaxial cable inside a 2mm OD nylon catheter embedded in brain tissue. The SAR is calculated in the plane of symmetry of the dipole antenna along a diagonal transect from the array to an antenna. The array is a square of 3cm side length; for such spacing, coupling among antennas is small. For resonant antennas, all driving frequencies produced an SAR at the array center at least half of the maximum value. The frequencies 300 and 400 MHz produced the most uniform SAR patterns, with no point on the transect less than half the maximum value. However, the resonant halflength for these frequencies is 7.2cm or greater, too large for most tumors. For h=3cm (dipole length=tumor length=6cm) the 300 and 400 MHz frequencies produced small values of SAR away from the antennas. The greatest SAR at the array center occurred at 700 to 915 MHz; however, the SAR pattern was not uniform. Another way to heat a 6cm tumor is to use a monopole over a ground plane with h=6cm. For this antenna half-length, 500 and 600 MHz gave the greatest array center SAR. At these frequencies the pattern was more uniform than at 700 MHz, but less uniform than at 400 MHz

  9. Calculation of the self-consistent current distribution and coupling of an RF antenna array

    International Nuclear Information System (INIS)

    A self-consistent calculation of the antenna current distribution and fields in an axisymmetric cylindrical geometry for the ICRH antenna-plasma coupling problem is presented. Several features distinguish this calculation from other codes presently available. 1. Variational form: The formulation of the self consistent antenna current problem in a variational form allows good convergence and stability of the algorithm. 2. Multiple straps: Allows modelling of (a) the current distribution across the width of the strap (by dividing it up into sub straps) (b) side limiters and septum (c) antenna cross-coupling. 3. Analytic calculation of the antenna field and calculation of the antenna self-consistent current distribution, (given the surface impedance matrix) gives rapid calculation. 4. Framed for parallel computation on several different parallel architectures (as well as serial) gives a large speed improvement to the user. Results are presented for both Alfven wave heating and current drive antenna arrays, showing the optimal coupling to be achieved for toroidal mode numbers 8< n<10 for typical ASDEX upgrade plasmas. Simulations of the ASDEX upgrade antenna show the importance of the current distribution across the antenna and of image currents flowing in the side limiters, and an analysis of a proposed asymmetric ITER antenna is presented. (orig.)

  10. Characteristics of block-periodic phased-array antennas with circular polarization of the radiated field

    Science.gov (United States)

    Likhoded, Iu. V.; Mironnikov, A. S.

    1990-02-01

    The paper presents results of a numerical investigation of the directivity characteristics of a block-periodic waveguide phased-array antenna with circular polarization of the radiated field. The advantages of this array from the viewpoint of maximining the ellipticity coefficent of the radiated field in the scanning sector are pointed out.

  11. PHASIM, a sophisticated phased array antenna software simulator implemented in MATLAB 5.2

    NARCIS (Netherlands)

    Keizer, W.P.M.N.

    1999-01-01

    A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This simulator is coded in MATLAB version 5.2. Using MATLAB, numerical engineering problems can be solved in a fraction of time of time required by programs coded in FORT

  12. High-gain textile antenna array system for off-body communication

    OpenAIRE

    Dries Vande Ginste; Hendrik Rogier; Luigi Vallozzi; Maria Lucia Scarpello

    2012-01-01

    A novel high-gain textile antenna array system, fully integrated into a rescue-worker’s vest and operating in the Industrial, Scientific, and Medical wireless band (2.4–2.4835 GHz), is presented. The system comprises an array consisting of four tip-truncated equilateral triangular microstrip patch antennas (ETMPAs), a power divider, line stretchers, and coaxial cables. The array is vertically positioned on the human torso to produce a narrow beam in elevation, as such reducing fading and allo...

  13. Wideband Circularly Polarized SIW Antenna Array That Uses Sequential Rotation Feeding

    Directory of Open Access Journals (Sweden)

    Fang-Fang Fan

    2014-01-01

    Full Text Available A wideband right-handed circularly polarized (CP substrate integrated waveguide- (SIW- based diamond ring-slot antenna array at the X-band is presented in this study. The array consists of four elements that exhibit wideband impedance matching characteristics and good radiation performance. The array also employs a sequential rotation feeding method to achieve the wideband axial ratio (AR bandwidth. The feeding network is based on the SIW power divider with a delay line related to sequential rotation feeding. To validate our design, an antenna array is fabricated and measured. The measured impedance and AR bandwidths are 19.2% (VSWR<2 and 14.1% (AR<3 dB, respectively. Moreover, the antenna has a stable CP peak gain of more than 12 dBic from 10.1 GHz to 10.7 GHz.

  14. SCRLH-TL Based Sequential Rotation Feed Network for Broadband Circularly Polarized Antenna Array

    Directory of Open Access Journals (Sweden)

    B. F. Zong

    2016-04-01

    Full Text Available In this paper, a broadband circularly polarized (CP microstrip antenna array using composite right/left-handed transmission line (SCRLH-TL based sequential rotation (SR feed network is presented. The characteristics of a SCRLH-TL are initially investigated. Then, a broadband and low insertion loss 45º phase shifter is designed using the SCRLH-TL and the phase shifter is employed in constructing a SR feed network for CP antenna array. To validate the design method of the SR feed network, a 2×2 antenna array comprising sequentially rotated coupled stacked CP antenna elements is designed, fabricated and measured. Both the simulated and measured results indicate that the performances of the antenna element are further enhanced when the SR network is used. The antenna array exhibits the VSWR less than 1.8 dB from 4 GHz to 7 GHz and the 3 dB axial ratio (AR from 4.4 GHz to 6.8 GHz. Also, high peak gain of 13.7 dBic is obtained. Besides, the normalized radiation patterns at the operating frequencies are symmetrical and the side lobe levels are low at φ=0º and φ=90º.

  15. Dual Polarization Multi-Frequency Antenna Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovative approaches for broadband multi-function antennas that conserve vehicle weight and reduce drag are welcome solutions for all airborne platforms including...

  16. Development And Test of A Digitally Steered Antenna Array for The Navigator GPS Receiver

    Science.gov (United States)

    Pinto, Heitor David; Valdez, Jennifer E.; Winternitz, Luke M. B.; Hassouneh, Munther A.; Price, Samuel R.

    2012-01-01

    Global Positioning System (GPS)-based navigation has become common for low-Earth orbit spacecraft as the signal environment is similar to that on the Earth s surface. The situation changes abruptly, however, for spacecraft whose orbital altitudes exceed that of the GPS constellation. Visibility is dramatically reduced and signals that are present may be very weak and more susceptible to interference. GPS receivers effective at these altitudes require increased sensitivity, which often requires a high-gain antenna. Pointing such an antenna can pose a challenge. One efficient approach to mitigate these problems is the use of a digitally steered antenna array. Such an antenna can optimally allocate gain toward desired signal sources and away from interferers. This paper presents preliminary results in the development and test of a digitally steered antenna array for the Navigator GPS research program at NASA s Goddard Space Flight Center. In particular, this paper highlights the development of an array and front-end electronics, the development and test of a real-time software GPS receiver, and implementation of three beamforming methods for combining the signals from the array. Additionally, this paper discusses the development of a GPS signal simulator which produces digital samples of the GPS L1C/A signals as they would be received by an arbitrary antenna array configuration. The simulator models transmitter and receiver dynamics, near-far and multipath interference, and has been a critical component in both the development and test of the GPS receiver. The GPS receiver system was tested with real and simulated GPS signals. Preliminary results show that performance improvement was achieved in both the weak signal and interference environments, matching analytical predictions. This paper summarizes our initial findings and discusses the advantages and limitations of the antenna array and the various beamforming methods.

  17. Directions of arrival estimation with planar antenna arrays in the presence of mutual coupling

    Science.gov (United States)

    Akkar, Salem; Harabi, Ferid; Gharsallah, Ali

    2013-06-01

    Directions of arrival (DoAs) estimation of multiple sources using an antenna array is a challenging topic in wireless communication. The DoAs estimation accuracy depends not only on the selected technique and algorithm, but also on the geometrical configuration of the antenna array used during the estimation. In this article the robustness of common planar antenna arrays against unaccounted mutual coupling is examined and their DoAs estimation capabilities are compared and analysed through computer simulations using the well-known MUltiple SIgnal Classification (MUSIC) algorithm. Our analysis is based on an electromagnetic concept to calculate an approximation of the impedance matrices that define the mutual coupling matrix (MCM). Furthermore, a CRB analysis is presented and used as an asymptotic performance benchmark of the studied antenna arrays. The impact of the studied antenna arrays geometry on the MCM structure is also investigated. Simulation results show that the UCCA has more robustness against unaccounted mutual coupling and performs better results than both UCA and URA geometries. The performed simulations confirm also that, although the UCCA achieves better performance under complicated scenarios, the URA shows better asymptotic (CRB) behaviour which promises more accuracy on DoAs estimation.

  18. Dual-polarization, wideband microstrip antenna array for airborne C-band SAR

    DEFF Research Database (Denmark)

    Granholm, Johan; Skou, Niels

    2000-01-01

    The paper describes the development of a C-band, dual linear polarization wideband antenna array, for use in the next-generation of the Danish airborne polarimetric synthetic aperture radar (SAR) system. The array is made of probe-fed, stacked microstrip patches. The design and performance...... of the basic stacked patch element, operating from 4.9 GHz to 5.7 GHz, and a 2×2 element test array of these, are described....

  19. Wideband Circularly Polarized SIW Antenna Array That Uses Sequential Rotation Feeding

    OpenAIRE

    Fang-Fang Fan; Ze-Hong Yan; Wei Wang

    2014-01-01

    A wideband right-handed circularly polarized (CP) substrate integrated waveguide- (SIW-) based diamond ring-slot antenna array at the X-band is presented in this study. The array consists of four elements that exhibit wideband impedance matching characteristics and good radiation performance. The array also employs a sequential rotation feeding method to achieve the wideband axial ratio (AR) bandwidth. The feeding network is based on the SIW power divider with a delay line related to sequenti...

  20. Advanced optimization algorithms for sensor arrays and multi-antenna communications

    OpenAIRE

    Abrudan, Traian

    2008-01-01

    Optimization problems arise frequently in sensor array and multi-channel signal processing applications. Often, optimization needs to be performed subject to a matrix constraint. In particular, unitary matrices play a crucial role in communications and sensor array signal processing. They are involved in almost all modern multi-antenna transceiver techniques, as well as sensor array applications in biomedicine, machine learning and vision, astronomy and radars. In this thesis, algorithms...

  1. Polymer (PDMS-Fe3O4) magneto-dielectric substrate for a MIMO antenna array

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Kamarudin, Muhammad Ramlee

    2016-01-01

    This paper presents the design of a 2 × 4 multiple-input multiple-output (MIMO) antenna array fabricated on a nanocomposite magneto-dielectric polymer substrate. The 10-nm iron oxide (Fe3O4) nanoparticles and polydimethylsiloxane (PDMS) composite is used as substrate to enhance the performance of a MIMO antenna array. The measured results showed up to 40.8 % enhancement in terms of bandwidth, 9.95 dB gain, and 57 % of radiation efficiency. Furthermore, it is found that the proposed magneto-dielectric (PDMS-Fe3O4) composite substrate provides excellent MIMO parameters such as correlation coefficient, diversity gain, and mutual coupling. The prototype of the proposed antenna is transparent, flexible, lightweight, and resistant against dust and corrosion. Measured results indicate that the proposed antenna is suitable for WLAN and ultra-wideband biomedical applications within frequency range of 5.33-7.70 GHz.

  2. BER Performance Evaluation of two Types of Antenna Array-Based Receivers in a Multipath Channel

    Directory of Open Access Journals (Sweden)

    Rim Haddad

    2010-11-01

    Full Text Available Smart antennasystems have received much attention in the last few years because they can increasesystem capacity by dynamically tuning out interference while focusing on the intended user.In this paper, we focused our research on the performance of two kinds of smart antenna receivers. Ananalytical model is proposed for evaluating the BER performance using a closed-form expression. Also,for the adaptive array, a simple way to account the multi-access interference can be exploited to evaluatethe average probability of error when the users are randomly distributed within an angular sector.The proposed model confirms the benefits of adaptive antennas in reducing the overall interference level(intercell/intracell and to find an accurate approximation of the error probability.In the two kinds of receivers, we assessed the impact of smart antenna systems and we considered thecase of conventional single antenna receiver model as reference (single user/single antenna.

  3. Beamforming Errors in Murchison Widefield Array Phased Array Antennas and their effects on Epoch of Reionization Science

    CERN Document Server

    Neben, A R; Bradley, R F; Dillon, J S; Bernardi, G; Bowman, J D; Briggs, F; Cappallo, R J; Corey, B E; Deshpande, A A; Goeke, R; Greenhill, L J; Hazelton, B J; Johnston-Hollitt, M; Kaplan, D L; Lonsdale, C J; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Ord, S M; Prabu, T; Shankar, N Udaya; Srivani, K S; Subrahmanyan, R; Tingay, S J; Wayth, R B; Webster, R L; Williams, A; Williams, C L

    2016-01-01

    Accurate antenna beam models are critical for radio observations aiming to isolate the redshifted 21cm spectral line emission from the Dark Ages and the Epoch of Reionization and unlock the scientific potential of 21cm cosmology. Past work has focused on characterizing mean antenna beam models using either satellite signals or astronomical sources as calibrators, but antenna-to-antenna variation due to imperfect instrumentation has remained unexplored. We characterize this variation for the Murchison Widefield Array (MWA) through laboratory measurements and simulations, finding typical deviations of order +/- 10-20% near the edges of the main lobe and in the sidelobes. We consider the ramifications of these results for image- and power spectrum-based science. In particular, we simulate visibilities measured by a 100m baseline and find that using an otherwise perfect foreground model, unmodeled beamforming errors severely limit foreground subtraction accuracy within the region of Fourier space contaminated by ...

  4. Field Deployment of Prototype Antenna Tiles for the Mileura Widefield Array--Low Frequency Demonstrator

    OpenAIRE

    Bowman, Judd D.; Barnes, David G.; Briggs, Frank H.; Corey, Brian E.; Lynch, Merv J.; Bhat, N. D. Ramesh; Cappallo, Roger J.; Doeleman, Sheperd S.; Fanous, Brian J.; Herne, David; Hewitt, Jacqueline N.; Johnston, Chris; Kasper, Justin C.; Kocz, Jonathon; Kratzenberg, Eric

    2006-01-01

    Experiments were performed with prototype antenna tiles for the Mileura Widefield Array--Low Frequency Demonstrator (MWA-LFD) to better understand the widefield, wideband properties of their design and to characterize the radio frequency interference (RFI) between 80 and 300 MHz at the site in Western Australia. Observations acquired during the six month deployment confirmed the predicted sensitivity of the antennas, sky-noise dominated system temperatures, and phase-coherent interferometric ...

  5. Uniplanar Millimeter-Wave Log-Periodic Dipole Array Antenna Fed by Coplanar Waveguide

    OpenAIRE

    Jianjun Gao; Shouzheng Zhu; Qiuyan Yin; Yong Cheng; Guohua Zhai

    2013-01-01

    A uniplanar millimeter-wave broadband printed log-periodic dipole array (PLPDA) antenna fed by coplanar waveguide (CPW) is introduced. This proposed structure consists of several active dipole elements, feeding lines, parallel coupled line, and the CPW, which are etched on a single metallic layer of the substrate. The parallel coupled line can be optimized to act as a transformer between the CPW and the PLPDA antenna. Meanwhile, this transform performs the task of a balun to achieve a wideban...

  6. Dual Circularly Polarized Omnidirectional Antenna with Slot Array on Coaxial Cylinder

    OpenAIRE

    Bin Zhou; Junping Geng; Zhe Li; Wenzhi Wang; Xianling Liang; Ronghong Jin

    2015-01-01

    A dual circularly polarized (CP) omnidirectional antenna based on slot array in coaxial cylinder structure is presented in this paper. It is constructed by perpendicular slot pairs around and along the axis of the coaxial cylinder to realize the omnidirectional CP property, and two ports are assigned in its two sides as left hand circularly polarized (LHCP) port and right hand circularly polarized (RHCP) port, respectively. The proposed antenna achieves a bandwidth of 16.4% ranging from 5.05 ...

  7. An Efficient ICT Method for Analysis of Co-planar Dipole Antenna Arrays of Arbitrary Lengths

    OpenAIRE

    Imoro, Adam Icarus; Aoki, Ippo; Inagaki, Naoki; Kikuma, Nobuyoshi; キクマ, ノブヨシ; 菊間, 信良

    1998-01-01

    A more judicious choice of trial functions to implement the Improved Circuit Theory (ICT) application to multi-element antennas is achieved. These new trial functions, based on Tai's modified variational implementation for single element antennas, leads to an ICT implementation applicable to much longer co-planar dipole arrays. The accuracy of the generalized impedance formulas is in good agreement with the method of moments. Moreover, all these generalized formulas including the radiation pa...

  8. Advanced integrated optical beam forming networks for broadband phased array antenna systems

    OpenAIRE

    Burla, Maurizio

    2013-01-01

    Since the first half of the twentieth century, a large interest has been addressed by the scientific and engineering community to the world of phased arrays antennas. Their technology started to be developed during the Second World War for early warning radar techniques to identify threats from the skies. Those capable antennas have been deployed over the years in a number of diversified fields to address different applications needs. First employed almost exclusively in the defense and space...

  9. OUT PERFORMANCE OF CUCKOO SEARCH ALGORITHM AMONG NATURE INSPIRED ALGORITHMS IN PLANAR ANTENNA ARRAYS

    Directory of Open Access Journals (Sweden)

    A.Sai Charan

    2014-07-01

    Full Text Available In this modern era a great deal of metamorphism is observed around us which eventuate due to some minute modifications and innovations in the area of Science and Technology. This paper deals with the application of a meta heuristic optimization algorithm namely the Cuckoo Search Algorithm in the design of an optimized planar antenna array which ensures high gain ,directivity, suppression of side lobes, increased efficiency and improves other antenna parameters

  10. Out Performance Of Cuckoo Search Algorithm Among Nature Inspired Algorithms in Planar Antenna Arrays

    OpenAIRE

    A.Sai Charan; Manasa, N. K.; N.V.S.N Sarma

    2014-01-01

    In this modern era a great deal of metamorphism is observed around us which eventuate due to some minute modifications and innovations in the area of Science and Technology. This paper deals with the application of a meta heuristic optimization algori thm namely the Cuckoo Search Algorithm in the desig n of an optimized planar antenna array which ensures high gain ,directivity, suppression of side lobes, increased efficiency and improves other antenna par ameters...

  11. Understanding and optimizing microstrip patch antenna cross polarization radiation on element level for demanding phased array antennas in weather radar applications

    Science.gov (United States)

    Vollbracht, D.

    2015-11-01

    The antenna cross polarization suppression (CPS) is of significant importance for the accurate calculation of polarimetric weather radar moments. State-of-the-art reflector antennas fulfill these requirements, but phased array antennas are changing their CPS during the main beam shift, off-broadside direction. Since the cross polarization (x-pol) of the array pattern is affected by the x-pol element factor, the single antenna element should be designed for maximum CPS, not only at broadside, but also for the complete angular electronic scan (e-scan) range of the phased array antenna main beam positions. Different methods for reducing the x-pol radiation from microstrip patch antenna elements, available from literature sources, are discussed and summarized. The potential x-pol sources from probe fed microstrip patch antennas are investigated. Due to the lack of literature references, circular and square shaped X-Band radiators are compared in their x-pol performance and the microstrip patch antenna size variation was analyzed for improved x-pol pattern. Furthermore, the most promising technique for the reduction of x-pol radiation, namely "differential feeding with two RF signals 180° out of phase", is compared to single fed patch antennas and thoroughly investigated for phased array applications with simulation results from CST MICROWAVE STUDIO (CST MWS). A new explanation for the excellent port isolation of dual linear polarized and differential fed patch antennas is given graphically. The antenna radiation pattern from single fed and differential fed microstrip patch antennas are analyzed and the shapes of the x-pol patterns are discussed with the well-known cavity model. Moreover, two new visual based electromagnetic approaches for the explanation of the x-pol generation will be given: the field line approach and the surface current distribution approach provide new insight in understanding the generation of x-pol component in microstrip patch antenna radiation

  12. Integrated Antenna/Solar Array Cell (IA/SAC) System for Flexible Access Communications

    Science.gov (United States)

    Lee, Ricard Q.; Clark, Eric B.; Pal, Anna Maria T.; Wilt, David M.; Mueller, Carl H.

    2004-01-01

    Present satellite communications systems normally use separate solar cells and antennas. Since solar cells generally account for the largest surface area of the spacecraft, co-locating the antenna and solar cells on the same substrate opens the possibility for a number of data-rate-enhancing communications link architecture that would have minimal impact on spacecraft weight and size. The idea of integrating printed planar antenna and solar array cells on the same surface has been reported in the literature. The early work merely attempted to demonstrate the feasibility by placing commercial solar cells besides a patch antenna. Recently, Integrating multiple antenna elements and solar cell arrays on the same surface was reported for both space and terrestrial applications. The application of photovoltaic solar cell in a planar antenna structure where the radiating patch antenna is replaced by a Si solar cell has been demonstrated in wireless communication systems (C. Bendel, J. Kirchhof and N. Henze, 3rd Would Photovotaic Congress, Osaka, Japan, May 2003). Based on a hybrid approach, a 6x1 slot array with circularly polarized crossdipole elements co-located on the same surface of the solar cells array has been demonstrated (S. Vaccaro, J. R. Mosig and P. de Maagt, IEEE Trans. Ant. and Propag., Vol. 5 1, No. 8, Aug. 2003). Amorphous silicon solar cells with about 5-10% efficiency were used in these demonstrations. This paper describes recent effort to integrate advanced solar cells with printed planar antennas. Compared to prior art, the proposed WSAC concept is unique in the following ways: 1) Active antenna element will be used to achieve dynamic beam steering; 2) High efficiency (30%) GaAs multi-junction solar cells will be used instead of Si, which has an efficiency of about 15%; 3) Antenna and solar cells are integrated on a common GaAs substrate; and 4) Higher data rate capability. The IA/SAC is designed to operate at X-band (8-12 GH) and higher frequencies

  13. Microwave absorbing properties of the Archimedean plane spiral antenna array/epoxy resin composites

    International Nuclear Information System (INIS)

    Microwave absorption of composites containing the Archimedean plane spiral antenna arrays was investigated. The results show that the absorptivity greatly depends on increasing the magnitude of resistance connecting the two arms of the spiral antenna, first increasing and then decreasing. When the magnitude of resistance is 510 Ω, the bandwidth below -10 dB is 10.4 GHz (making up 86.7% of the frequency range 6-18 GHz), and the minimum reflection loss reaches -29.6 dB. The absorbing properties of composites fall with decreasing the initial radius and arm width of the spiral antenna

  14. Parallel-fed planar dipole antenna arrays for low-observable platforms

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book focuses on determination of scattering of parallel-fed planar dipole arrays in terms of reflection and transmission coefficients at different levels of the array system. In aerospace vehicles, the phased arrays are often in planar configuration. The radar cross section (RCS) of the vehicle is mainly due to its structure and the antennas mounted over it. There can be situation when the signatures due to antennas dominate over the structural RCS of the platform. This necessitates the study towards the reduction and control of antenna/ array RCS. The planar dipole array is considered as a stacked linear dipole array. A systematic, step-by-step approach is used to determine the RCS pattern including the finite dimensions of dipole antenna elements. The mutual impedance between the dipole elements for planar configuration is determined. The scattering till second-level of couplers in parallel feed network is taken into account. The phase shifters are modelled as delay line. All the couplers in the feed n...

  15. Proximity fed gap-coupled half E-shaped microstrip antenna array

    Indian Academy of Sciences (India)

    Amit A Deshmukh; K P Ray

    2015-02-01

    Broadband gap-coupled array configuration of proximity fed rectangular microstrip antenna with half E-shaped microstrip antennas are proposed. The rectangular slot in half E-shaped patch reduces the orthogonal TM01 mode resonance frequency of equivalent rectangular patch and along with TM10 modes of fed and parasitic rectangular patches, yields broader bandwidth of more than 470 MHz (> 45%). An improvement in radiation pattern and gain characteristics over the bandwidth is obtained by gap-coupling half E-shaped patches along all the edges of proximity fed rectangular patch, which yields bandwidth of nearly 510 MHz (∼49%). Further to enhance the gain, a gap-coupled 3 × 3 array configuration of half E-shaped patches with proximity fed rectangular microstrip antenna is proposed. The gap-coupled array configuration yields bandwidth of more than 530 MHz (>50%) with broadside radiation pattern and peak gain of 11 dBi.

  16. Determining Direction of Arrival at a Y-Shaped Antenna Array

    Science.gov (United States)

    Starr, Stan

    2003-01-01

    An algorithm computes the direction of arrival (both azimuth and elevation angles) of a lightning-induced electromagnetic signal from differences among the times of arrival of the signal at four antennas in a Y-shaped array on the ground. In the original intended application of the algorithm, the baselines of the array are about 90 m long and the array is part of a lightning-detection-and-ranging (LDAR) system. The algorithm and its underlying equations can also be used to compute directions of arrival of impulsive phenomena other than lightning on arrays of sensors other than radio antennas: for example, of an acoustic pulse arriving at an array of microphones.

  17. Corporate-Feed Multilayer Bow-Tie Antenna Array Design Using a Simple Transmission Line Model

    Directory of Open Access Journals (Sweden)

    S. Didouh

    2012-01-01

    Full Text Available A transmission line model is used to design corporate-fed multilayered bow-tie antennas arrays; the simulated antennas arrays are designed to resonate at the frequencies 2.4 GHz, 5 GHz, and 8 GHz corresponding to RFID, WIFI, and radars applications. The contribution of this paper consists of modeling multilayer bow-tie antenna array fed through an aperture using transmission line model. The transmission line model is simple and precise and allows taking into account the whole geometrical, electrical, and technological characteristics of the antennas arrays. The proposed transmission line model showed its interest in the design of different multilayered bow-tie antennas and predicted the correct resonance frequency for different applications in telecommunications. To validate the proposed transmission line model, the simulation results obtained are compared with those obtained by the method of moments. The results of simulations are presented and discussed. Using this transmission line approach, the resonant frequency, input impedance, and return loss can be determined simultaneously. The paper reports several simulation results that confirm the validity of the developed model. The obtained results are then presented and discussed.

  18. Precise Calibration of a GNSS Antenna Array for Adaptive Beamforming Applications

    Directory of Open Access Journals (Sweden)

    Saeed Daneshmand

    2014-05-01

    Full Text Available The use of global navigation satellite system (GNSS antenna arrays for applications such as interference counter-measure, attitude determination and signal-to-noise ratio (SNR enhancement is attracting significant attention. However, precise antenna array calibration remains a major challenge. This paper proposes a new method for calibrating a GNSS antenna array using live signals and an inertial measurement unit (IMU. Moreover, a second method that employs the calibration results for the estimation of steering vectors is also proposed. These two methods are applied to the receiver in two modes, namely calibration and operation. In the calibration mode, a two-stage optimization for precise calibration is used; in the first stage, constant uncertainties are estimated while in the second stage, the dependency of each antenna element gain and phase patterns to the received signal direction of arrival (DOA is considered for refined calibration. In the operation mode, a low-complexity iterative and fast-converging method is applied to estimate the satellite signal steering vectors using the calibration results. This makes the technique suitable for real-time applications employing a precisely calibrated antenna array. The proposed calibration method is applied to GPS signals to verify its applicability and assess its performance. Furthermore, the data set is used to evaluate the proposed iterative method in the receiver operation mode for two different applications, namely attitude determination and SNR enhancement.

  19. Multi-Objective Synthesis of Filtering Dipole Array Based on Tuning-Space Mapping

    Directory of Open Access Journals (Sweden)

    P. Vsetula

    2015-09-01

    Full Text Available In the paper, we apply tuning-space mapping to multi-objective synthesis of a filtering antenna. The antenna is going to be implemented as a planar dipole array with serial feeding. Thanks to the multi-objective approach, we can deal with conflicting requirements on gain, impedance matching, side-lobe level, and main-lobe direction. MOSOMA algorithm is applied to compute Pareto front of optimal solutions by changing lengths of dipoles and parameters of transmission lines connecting them into a serial array. Exploitation of tuning space mapping significantly reduces CPU-time demands of the multi-objective synthesis: a coarse optimization evaluates objectives using a wire model of the filtering array (4NEC2, method of moments, and a fine optimization exploits a realistic planar model of the array (CST Microwave Studio, finite integration technique. The synthesized filtering antenna was manufactured, and its parameters were measured to be compared with objectives. The number of dipoles in the array is shown to influence the match of measured parameters and objectives.

  20. SCRLH-TL Based Sequential Rotation Feed Network for Broadband Circularly Polarized Antenna Array

    OpenAIRE

    Zong, B. F.; Wang, G. M.; Zeng, H Y; Wang, Y.W.; Wang, D

    2016-01-01

    In this paper, a broadband circularly polarized (CP) microstrip antenna array using composite right/left-handed transmission line (SCRLH-TL) based sequential rotation (SR) feed network is presented. The characteristics of a SCRLH-TL are initially investigated. Then, a broadband and low insertion loss 45º phase shifter is designed using the SCRLH-TL and the phase shifter is employed in constructing a SR feed network for CP antenna array. To validate the design method of the SR feed network, a ...

  1. Design of a Compact Wideband Antenna Array for Microwave Imaging Applications

    OpenAIRE

    J. Puskely; Mikulasek, T.; Z. Raida

    2013-01-01

    In the paper, wideband antenna arrays aimed at microwave imaging applications and SAR applications operating at Ka band were designed. The antenna array feeding network is realized by a low-loss SIW technology. Moreover, we have replaced the large feed network comprised of various T and Y junctions by a simple broadband network of compact size to more reduce losses in the substrate integrated waveguide and also save space on the PCB. The designed power 8-way divider is complemented by a wideb...

  2. Research on Helicopter-borne MIMO Microwave Imaging Technology Based on Arc Antenna Array

    Directory of Open Access Journals (Sweden)

    Huang Ping-ping

    2015-02-01

    Full Text Available This study proposes a novel Multiple Input Multiple Output (MIMO microwave imaging mode based on arc antenna array, which is mounted on the belly of platform. In this mode, an arc aperture is quickly synthesized using an MIMO. Consequently, high space and time resolution images of the illuminated scene around the platform are acquired. First, an imaging principle model based on arc antenna array is described, and its signal model is developed. Then, an imaging algorithm based on confocal projection is discussed and the performance of the mode is analyzed. Finally, the feasibility of the imaging mode and the validity of the proposed algorithm are demonstrated with a numerical simulation.

  3. Optically Controlled Reconfigurable Antenna Array Based on E-Shaped Elements

    Directory of Open Access Journals (Sweden)

    Arismar Cerqueira Sodré Junior

    2014-01-01

    Full Text Available This work presents the development of optically controlled reconfigurable antenna arrays. They are based on two patch elements with E-shaped slots, a printed probe, and a photoconductive switch made from an intrinsic silicon die. Numerical simulations and experiments have been shown to be in agreement, and both demonstrate that the frequency response of the antenna arrays can be efficiently reconfigured over two different frequency ISM bands, namely, 2.4 and 5 GHz. A measured gain of 12.5 dBi has been obtained through the use of two radiating elements printed in a low-cost substrate and a dihedral corner reflector.

  4. Possibilities of Phased Array Antenna (PAA) for Fusion

    International Nuclear Information System (INIS)

    Principles of the design and optimal choice of the PAA scheme for fusion researches are considered on the base of high power microwave antennas. Results of the analysis of the electromagnetic field structure in dependence on PAA sizes and radiator type are given

  5. Development of local oscillator integrated antenna array for microwave imaging diagnostics

    International Nuclear Information System (INIS)

    Microwave imaging diagnostics are powerful tools that are used to obtain details of complex structures and behaviors of such systems as magnetically confined plasmas. For example, microwave imaging reflectometry and microwave imaging interferometers are suitable for observing phenomena that are involved with electron density fluctuations; moreover, electron cyclotron emission imaging diagnostics enable us to accomplish the significant task of observing MHD instabilities in large tokamaks. However, microwave imaging systems include difficulties in terms of multi-channelization and cost. Recently, we solved these problems by developing a Horn-antenna Mixer Array (HMA), a 50 - 110 GHz 1-D heterodyne- type antenna array, which can be easily stacked as a 2-D receiving array, because it uses an end-fire element. However, the HMA still evidenced problems owing to the requirement for local oscillation (LO) optics and an expensive high-power LO source. To solve this problem, we have developed an upgraded HMA, named the Local Integrated Antenna array (LIA), in which each channel has an internal LO supply using a frequency multiplier integrated circuit. Therefore, the proposed antenna array eliminates the need for both the LO optics and the high-power LO source. This paper describes the principle of the LIA, and provides details about an 8 channel prototype LIA

  6. Development of local oscillator integrated antenna array for microwave imaging diagnostics

    Science.gov (United States)

    Kuwahara, D.; Ito, N.; Nagayama, Y.; Tsuchiya, H.; Yoshikawa, M.; Kohagura, J.; Yoshinaga, T.; Yamaguchi, S.; Kogi, Y.; Mase, A.; Shinohara, S.

    2015-12-01

    Microwave imaging diagnostics are powerful tools that are used to obtain details of complex structures and behaviors of such systems as magnetically confined plasmas. For example, microwave imaging reflectometry and microwave imaging interferometers are suitable for observing phenomena that are involved with electron density fluctuations; moreover, electron cyclotron emission imaging diagnostics enable us to accomplish the significant task of observing MHD instabilities in large tokamaks. However, microwave imaging systems include difficulties in terms of multi-channelization and cost. Recently, we solved these problems by developing a Horn-antenna Mixer Array (HMA), a 50 - 110 GHz 1-D heterodyne- type antenna array, which can be easily stacked as a 2-D receiving array, because it uses an end-fire element. However, the HMA still evidenced problems owing to the requirement for local oscillation (LO) optics and an expensive high-power LO source. To solve this problem, we have developed an upgraded HMA, named the Local Integrated Antenna array (LIA), in which each channel has an internal LO supply using a frequency multiplier integrated circuit. Therefore, the proposed antenna array eliminates the need for both the LO optics and the high-power LO source. This paper describes the principle of the LIA, and provides details about an 8 channel prototype LIA.

  7. Quadrature transmit array design using single-feed circularly polarized patch antenna for parallel transmission in MR imaging

    OpenAIRE

    Pang, Yong; Yu, Baiying; Daniel B Vigneron; Zhang, Xiaoliang

    2014-01-01

    Quadrature coils are often desired in MR applications because they can improve MR sensitivity and also reduce excitation power. In this work, we propose, for the first time, a quadrature array design strategy for parallel transmission at 298 MHz using single-feed circularly polarized (CP) patch antenna technique. Each array element is a nearly square ring microstrip antenna and is fed at a point on the diagonal of the antenna to generate quadrature magnetic fields. Compared with conventional ...

  8. Two-Element Tapered Slot Antenna Array for Terahertz Resonant Tunneling Diode Oscillators

    Directory of Open Access Journals (Sweden)

    Jianxiong Li

    2014-01-01

    Full Text Available Two-element tapered slot antenna (TSA array for terahertz (THz resonant tunneling diode (RTD oscillators is proposed in this paper. The proposed TSA array has the advantages of both the high directivity and high gain at the horizontal direction and hence can facilitate the horizontal communication between the RTD oscillators and other integrated circuit chips. A MIM (metal-insulator-metal stub with a T-shaped slot is used to reduce the mutual coupling between the TSA elements. The validity and feasibility of the proposed TSA array have been simulated and analyzed by the ANSYS/ANSOFT’s High Frequency Structure Simulator (HFSS. Detailed modeling approaches and theoretical analysis of the proposed TSA array have been fully addressed. The simulation results show that the mutual coupling between the TSA elements is reduced below −40 dB. Furthermore, at 500 GHz, the directivity, the gain, and the half power beam width (HPBW at the E-plane of the proposed TSA array are 12.18 dB, 13.09 dB, and 61°, respectively. The proposed analytical method and achieved performance are very promising for the antenna array integrated with the RTD oscillators at the THz frequency and could pave the way to the design of the THz antenna array for the RTD oscillators.

  9. Tracking antenna architectures based on an integrated mixer microstrip patch array

    International Nuclear Information System (INIS)

    The object of this work is to design, develop and characterize both theoretically and experimentally a compact integrated mixer microstrip patch antenna which exhibits a low level of cross-polarization. Modelling of this antenna using various CAD techniques and supporting measurements has led to a clearer understanding of its operation and the optimization of its design. The attractiveness of such a frequency scaleable design lies in the inherent simplicity and ease with which it can be used to produce an intermediate frequency (IF) signal with minimum circuit complexity and low cross-polar levels. The operation of the integrated mixer antenna circuit is exploited under the phenomenon of injection locking for its potential for direct phase modulation and detection. It leads to new vistas of study such as IF phase-shifterless beam steering. Here the desired phased shift is derived through injection locking and achieved solely by the DC bias control, thus eliminating the need for phase shifters and feed networks. A self-tracking integrated mixer array has also been described which uses an in-band pilot carrier signal for self-calibration. By minor alteration of the integrated antenna topology, a minimum complexity variant of a heterodyne retrodirective array has then been realized. These tracking antenna architectures minimize the problems of cost, complexity and size limitations associated with conventional phased arrays. These are designed for emerging commercial applications and are resolutions of some trade-offs that balance performance, cost and reliability. Theoretical and experimental results are presented to show their performances and, in addition, the practical requirements relevant to these are also addressed. The results indicate that these tracking antenna architectures based on an integrated mixer microstrip patch array could form a synergistic link with other emerging technologies and can be to some extent embodied in future phased array designs

  10. Design of Multilevel Sequential Rotation Feeding Networks Used for Circularly Polarized Microstrip Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Aixin Chen

    2012-01-01

    Full Text Available Sequential rotation feeding networks can significantly improve performance of the circularly polarized microstrip antenna array. In this paper, single, double, and multiple series-parallel sequential rotation feeding networks are examined. Compared with conventional parallel feeding structures, these multilevel feeding techniques present reduction of loss, increase of bandwidth, and improvement of radiation pattern and polarization purity. By using corner-truncated square patch as the array element and adopting appropriate level of sequential rotation series-parallel feeding structures as feeding networks, microstrip arrays can generate excellent circular polarization (CP over a relatively wide frequency band. They can find wide applications in phased array radar and satellite communication systems.

  11. THACO, a Test Facility for Characterizing the Noise Performance of Active Antenna Arrays

    CERN Document Server

    Woestenburg, E E M; Ruiter, M; Ivashina, M V; Witvers, R H

    2011-01-01

    This paper discusses an outdoor test facility for the noise characterization of active antenna arrays, using measurement results of array noise temperatures in the order of 50 K for a number of small aperture arrays. The measurement results are obtained by a Y-factor method with hot and a cold noise sources, with an absorber at room temperature as the hot load and the cold sky as the cold load. The effect of shielding the arrays by the test facility, with respect to noise and RFI from the environment, will also be discussed.

  12. An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

    CERN Document Server

    D'Addario, Larry R

    2016-01-01

    Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. For $N$ antennas, the cost and power consumption of cross-correlation are proportional to $N^2$ and dominate at sufficiently large $N$. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals ($N$=32 antennas with 2 opposite-polarization signals per antenna). When $N$ is larger, the input data are buffered in an on-chip memory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulat...

  13. Research on X band extended cosecant squared b eam synthesis of micro-strip antenna arrays using genetic algorithm%X波段微带余割平方扩展波束天线阵赋形优化遗传算法研究∗

    Institute of Scientific and Technical Information of China (English)

    张金玲; 万文钢; 郑占奇; 甘曦; 朱兴宇

    2015-01-01

    提出了一种改进型自适应遗传算法,该算法用logistic函数拟合交叉概率和变异概率,以赌轮盘选择和精英保留相结合的方式,在全局寻找最优解.与经典遗传算法相比,改进型自适应遗传算法可以大大提高算法的求解质量.本文基于改进的自适应遗传算法研究设计了−3 dB范围为0◦—12◦,−10 dB波束宽度为65◦,波束覆盖为65◦,天线频带范围为8.5—9.8 GHz,中心频率为9.05 GHz的X波段微带余割平方扩展波束天线阵.研究结果表明改进型自适应遗传算法对方向图的拟合程度具有较大提高,适应度值可以从0.07以下提升到0.09以上.%Synthesis of desired radiation patterns without an optimization algorithm is usually time consuming and inefficient. To achieve a desired radiation pattern such as cosecant squared beam and contoured beam, different evolutionary algorithms such as genetic algorithm (GA), particle swarm optimization algorithm, and invasive weed optimization algorithm have been used to find the excitation of radiation elements. Adaptive genetic algorithm (AGA) optimizer is a robust, stochastic search method, modeled on the principles and concepts of natural selection and evolution. As an optimizer, the powerful heuristic of the AGA is effective for solving complex and related problems. An improved AGA is proposed, in allusion to the characteristics of optimizing designs of antenna arrays which have many parameters and complicated structures. This algorithm constructs an adjustble formula to produce the crossover rate and mutation rate based on a logistic curve equation. In the way of combining roulette wheel selection and elitist strategy, this algorithm searches for the optimal solution in the global space, and is compared with the classical GA; the improved AGA has a better performance in seeking the solution. Taking the mutual coupling between the elements into account, we design the X band extended cosecant squared beam

  14. PHASED ARRAY ANTENNA AND BEAMFORMING SUBSYTEMS IN PHASEDARRAY RADAR

    OpenAIRE

    Dr A. Jhansi rani,; A. Jaya Lakshmi

    2010-01-01

    Phased array radars are essential for the future missions like Reusable Launch Vehicle (RLV), human space mission, and space debris tracking. The capabilities of Phased Array Radar include multipletarget long range tracking in skin mode, elimination of mechanical errors and instantaneous beam positioning capability. This paper presents the design of a transmitter/receiver Digital Beam former (DBF) based on the mathematical model of a far-field plane wave incident on a sensor array. Simulation...

  15. Self-Steering Antenna Arrays for Distributed Picosatellite Networks

    OpenAIRE

    Murakami, Blaine; Ohta, Aaron; Tamamoto, Michael; Shiroma, Grant; Miyamoto, Ryan; Shiroma, Wayne

    2003-01-01

    The potential for using self-steering arrays for secure crosslinks in picosatellite networks is investigated. The principle of operation and methods of characterization of these so-called retrodirective arrays is reviewed, and examples developed by our group are presented. New challenges for the space environment are identified, specifically the development of two-dimensional, circularly polarized retrodirective arrays optimized for size and power consumption.

  16. Synthesis of Phase-Only Reconfigurable Linear Arrays Using Multiobjective Invasive Weed Optimization Based on Decomposition

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2014-01-01

    Full Text Available Synthesis of phase-only reconfigurable array aims at finding a common amplitude distribution and different phase distributions for the array to form different patterns. In this paper, the synthesis problem is formulated as a multiobjective optimization problem and solved by a new proposed algorithm MOEA/D-IWO. First, novel strategies are introduced in invasive weed optimization (IWO to make original IWO fit for solving multiobjective optimization problems; then, the modified IWO is integrated into the framework of the recently well proved competitive multiobjective optimization algorithm MOEA/D to form a new competitive MOEA/D-IWO algorithm. At last, two sets of experiments are carried out to illustrate the effectiveness of MOEA/D-IWO. In addition, MOEA/D-IWO is compared with MOEA/D-DE, a new version of MOEA/D. The comparing results show the superiority of MOEA/D-IWO and indicate its potential for solving the antenna array synthesis problems.

  17. Single-feed superconducting circularly polarized microstrip array antenna for direct-to-home receiving system

    International Nuclear Information System (INIS)

    Single-feed circularly polarized microstrip patch and patch array antennas for 'direct-to-home' receiving system at around 12 GHz are studied by theoretical analysis and experiments. A full-wave microwave circuit simulator (Em), based on the method of moments and capable of handling the microwave surface impedance, has been used in the theoretical analysis of the antennas. Antennas have been fabricated from both normal conductor (gold) and YBa2Cu3O7-x (YBCO) superconductor for comparison. Measured results on resonant frequency (fr), return loss, gain, bandwidth, and axial ratio are presented. The antennas are found to show a very low axial ratio and a moderate bandwidth. In the comparison of gain, the superconducting antennas showed a remarkable improvement over their gold counterparts. The receiving power of a four-element array fabricated from a single-side YBCO thin film on (100) MgO single crystal substrate is found to be 1.8 dB higher than that of a gold array with identical configuration and both measured at 77 K. (author)

  18. Single-feed superconducting circularly polarized microstrip array antenna for direct-to-home receiving system

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.I.; Ehata, K.; Ohshima, S. [Faculty of Engineering, Yamagata University, Jonan 4-3-16, Yonezawa 992-8510 (Japan)

    2000-07-01

    Single-feed circularly polarized microstrip patch and patch array antennas for 'direct-to-home' receiving system at around 12 GHz are studied by theoretical analysis and experiments. A full-wave microwave circuit simulator (Em), based on the method of moments and capable of handling the microwave surface impedance, has been used in the theoretical analysis of the antennas. Antennas have been fabricated from both normal conductor (gold) and YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) superconductor for comparison. Measured results on resonant frequency (f{sub r}), return loss, gain, bandwidth, and axial ratio are presented. The antennas are found to show a very low axial ratio and a moderate bandwidth. In the comparison of gain, the superconducting antennas showed a remarkable improvement over their gold counterparts. The receiving power of a four-element array fabricated from a single-side YBCO thin film on (100) MgO single crystal substrate is found to be 1.8 dB higher than that of a gold array with identical configuration and both measured at 77 K. (author)

  19. The application of taylor weighting, digital phase shifters, and digital attenuators to phased-array antennas.

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Billy C.

    2008-03-01

    Application of Taylor weighting (taper) to an antenna aperture can achieve low peak sidelobes, but combining the Taylor weighting with quantized attenuators and phase shifters at each radiating element will impact the performance of a phased-array antenna. An examination of array performance is undertaken from the simple point of view of the characteristics of the array factor. Design rules and guidelines for determining the Taylor-weighting parameters, the number of bits required for the digital phase shifter, and the dynamic range and number of bits required for the digital attenuator are developed. For a radar application, when each element is fed directly from a transmit/receive module, the total power radiated by the array will be reduced as a result of the taper. Consequently, the issue of whether to apply the taper on both transmit and receive configurations, or only on the receive configuration is examined with respect to two-way sidelobe performance.

  20. The 20 GHz circularly polarized, high temperature superconducting microstrip antenna array

    Science.gov (United States)

    Morrow, Jarrett D.; Williams, Jeffery T.; Long, Stuart A.; Wolfe, John C.

    1994-01-01

    The primary goal was to design and characterize a four-element, 20 GHz, circularly polarized microstrip patch antenna fabricated from YBa2Cu3O(x) superconductor. The purpose is to support a high temperature superconductivity flight communications experiment between the space shuttle orbiter and the ACTS satellite. This study is intended to provide information into the design, construction, and feasibility of a circularly polarized superconducting 20 GHz downlink or cross-link antenna. We have demonstrated that significant gain improvements can be realized by using superconducting materials for large corporate fed array antennas. In addition, we have shown that when constructed from superconducting materials, the efficiency, and therefore the gain, of microstrip patches increases if the substrate is not so thick that the dominant loss mechanism for the patch is radiation into the surface waves of the conductor-backed substrate. We have considered two design configurations for a superconducting 20 GHz four-element circularly polarized microstrip antenna array. The first is the Huang array that uses properly oriented and phased linearly polarized microstrip patch elements to realize a circularly polarized pattern. The second is a gap-coupled array of circularly polarized elements. In this study we determined that although the Huang array operates well on low dielectric constant substrates, its performance becomes extremely sensitive to mismatches, interelement coupling, and design imperfections for substrates with high dielectric constants. For the gap-coupled microstrip array, we were able to fabricate and test circularly polarized elements and four-element arrays on LaAlO3 using sputtered copper films. These antennas were found to perform well, with relatively good circular polarization. In addition, we realized a four-element YBa2Cu3O(x) array of the same design and measured its pattern and gain relative to a room temperature copper array. The patterns were

  1. Phase conjugation method and apparatus for an active retrodirective antenna array

    Science.gov (United States)

    Tausworthe, R. C.; Chernoff, R. C. (Inventor)

    1979-01-01

    An active retrodirective antenna array wherein a reference array element is used to generate a phase reference which is replicated at succeeding elements of the array. Each element of the array is associated with a phase regeneration circuit and the phase conjugation circuitry of an adjacent element. In one implementation, the phase reference circuit operates on the input signal at the reference element, a voltage controlled oscillator (VCO) output signal and the input pilot signal at the next array element received from a transmission line. By proper filtering and mixing, a phase component may be produced to which the VCO may be locked to produce the phase conjugate of the pilot signal at the next array element plus a transmission line delay. In another implementation, particularly suited for large arrays in space, two different input pilot frequencies are employed.

  2. Novel microstrip antenna array for anti-jam satellite navigation system

    OpenAIRE

    Martynyuk, Sergiy Ye.; Vasylenko, Dmytro O.; Dubrovka, Fedor F.; Laush, Anatolii G.

    2015-01-01

    We present results of theoretical and experimental investigations of a novel dual band right hand circularly polarized microstrip antenna array with adaptive space-time processing capability for terminal of GPS/GLONASS/GALILEO satellite navigation systems. The array structure is composed from 10 microstrip radiators excited independently via separate coaxial input ports. Two central radiating elements for two frequency bands (L1 and L2) have got circular shapes with slits and are stacked to p...

  3. Design of Multilevel Sequential Rotation Feeding Networks Used for Circularly Polarized Microstrip Antenna Arrays

    OpenAIRE

    Aixin Chen; Chuo Yang; Zhizhang (David) Chen; Yanjun Zhang; Yingyi He

    2012-01-01

    Sequential rotation feeding networks can significantly improve performance of the circularly polarized microstrip antenna array. In this paper, single, double, and multiple series-parallel sequential rotation feeding networks are examined. Compared with conventional parallel feeding structures, these multilevel feeding techniques present reduction of loss, increase of bandwidth, and improvement of radiation pattern and polarization purity. By using corner-truncated square patch as the array e...

  4. Optimized Hyper Beamforming of Linear Antenna Arrays Using Collective Animal Behaviour

    OpenAIRE

    Gopi Ram; Durbadal Mandal; Rajib Kar; Sakti Prasad Ghoshal

    2013-01-01

    A novel optimization technique which is developed on mimicking the collective animal behaviour (CAB) is applied for the optimal design of hyper beamforming of linear antenna arrays. Hyper beamforming is based on sum and difference beam patterns of the array, each raised to the power of a hyperbeam exponent parameter. The optimized hyperbeam is achieved by optimization of current excitation weights and uniform interelement spacing. As compared to conventional hyper beamforming of linear antenn...

  5. Microwave holographic antenna array design by using psychophysical properties of eye

    OpenAIRE

    Titar, V. P.; Bogdanova, T. V.

    1995-01-01

    Microwave holographic systems use antenna arrays with elements distributed uniformly in the plane of receiving aperture. Such distribution provides decreasing the redundancy of registered holographic information, while the quality of images remains high (side lobes are suppressed). Design principles are proposed of microwave quasiperiodic holographic arrays, which can be synthesized by various space-time methods using the psychophysical properties of the human vision. Besides of the redundanc...

  6. Two-Element Tapered Slot Antenna Array for Terahertz Resonant Tunneling Diode Oscillators

    OpenAIRE

    Jianxiong Li; Yunxiang Li; Weiguang Shi; Haolin Jiang; Luhong Mao

    2014-01-01

    Two-element tapered slot antenna (TSA) array for terahertz (THz) resonant tunneling diode (RTD) oscillators is proposed in this paper. The proposed TSA array has the advantages of both the high directivity and high gain at the horizontal direction and hence can facilitate the horizontal communication between the RTD oscillators and other integrated circuit chips. A MIM (metal-insulator-metal) stub with a T-shaped slot is used to reduce the mutual coupling between the TSA elements. The validit...

  7. A Novel T-Fed 4-Element Quasi-Lumped Resonator Antenna Array

    Directory of Open Access Journals (Sweden)

    S.S. Olokede

    2014-06-01

    Full Text Available In this paper, electrically small corporately T-fed quasi-lumped element resonator antenna array is investigated. The radiating element, a quasi-lumped element resonator is excited by a novel semi hybrid ring-like T-shaped corporate feed network. The characteristics losses due to Ohmic and discontinuities along the feed line which invariably constitutes complex feed structures are mitigated at the instance of the proposed antenna. Technique to implement the compact array with the intent to enhance the gain is presented. The operation dynamics of the feed along with its theoretical explanation is also reported. Findings indicates that the measured gain is 10.97 dBi for antenna of an estate area of about 0.677λ_0 × 1.257λ_0 sq. mm. Valuable insight to the optimum design in terms of compactness, good gain, and ease of fabrication is documented.

  8. Covariance analysis and phase ambiguity resolution for a linear interferometer antenna array

    Science.gov (United States)

    Johnson, James Andrew

    This thesis explores the application of mathematical techniques for estimating the angle of arrival (AOA) using a receiving platform having a linear interferometer antenna array. It addresses the estimation accuracy of interferometer phase measurements of a signal with superposed Gaussian noise from multiple antenna baselines, and provides a method for resolving the modulo two-pi problem inherent to many phase measurement systems. The study extends prior theoretical work (Hanna, C., 1983) by laying a mathematical foundation to complement his geometrical approach, provides a robust method of performance prediction for such a system. Key elements include estimation accuracy of a signal parameter with additive noise; the design of the linear antenna array element spacings and the relationship to Diophantine equations; and the application of the Cramer-Rao lower bound on variance of parameter estimation. It is hoped that the work presented here will serve as a practical guide for research scientists and engineers.

  9. Correction of polarization error in scanned array weather radar antennas

    NARCIS (Netherlands)

    Pang, C.; Hoogeboom, P.; Russchenberg, H.; Wang, T.; Dong, J.; Wang, X.

    2014-01-01

    In this paper, the polarization error correction of dual-polarized planar scanned array weather radar in alternately transmitting and simultaneously receiving (ATSR) mode is analyzed. A method based on point correction and a method taking the complete array patterns into account are discussed. To an

  10. PHASED ARRAY ANTENNA AND BEAMFORMING SUBSYTEMS IN PHASEDARRAY RADAR

    Directory of Open Access Journals (Sweden)

    Dr A. Jhansi rani,

    2010-05-01

    Full Text Available Phased array radars are essential for the future missions like Reusable Launch Vehicle (RLV, human space mission, and space debris tracking. The capabilities of Phased Array Radar include multipletarget long range tracking in skin mode, elimination of mechanical errors and instantaneous beam positioning capability. This paper presents the design of a transmitter/receiver Digital Beam former (DBF based on the mathematical model of a far-field plane wave incident on a sensor array. Simulations of a DBF transmitter and receiver are performed to control the power pattern of a 4-element linear array. For the sensor array, two spatial filters were constructed with different pattern requirements to demonstrate theoperation of the Digital Beam Forming.

  11. Circular antenna array pattern analysis using radial basis function neural network

    International Nuclear Information System (INIS)

    A method is proposed to design circular antenna array for the given gain and beam width using Artificial Neural Networks. In optimizing circular arrays, the parameters to be controlled are excitation of the elements, their separation, lengths and the circle radius. This paper deals about finding the parameters of radiation pattern of given uniform circular antenna array. Initially, the network is trained with a set of input-output data pairs. The trained network is used for testing. The training data set is generated from MATLAB simulation with number of elements N=5, 10, 15 and 20 elements of uniform circular array, respectively, distributed over a given circle, assuming 20 training cases. The number of input nodes, hidden nodes and output nodes are 20, 20 and 1, respectively. Predicted values of the neural network are compared with those of MATLAB simulation results and are found to be in agreement. This work establishes the application of Radial Basis Function Neural Network (RBFNN) for circular array pattern optimization. RBFNN is able to predict the output values with 97% of accuracy. This work proves that RBFNN can be used for circular antenna array design.

  12. A Linear Antenna Array Failure Correction with Null Steering using Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Narwant Singh Grewal

    2014-03-01

    Full Text Available The element failure of digital beam forming array antenna systems used in defence equipment increases the side lobe power level which distorts the beam pattern of the antenna array. The problem of array failure correction becomes more complex when null steering conditions are required to be added. In this paper, the problem of linear antenna array failure has been addressed with multiple wide band null steering using firefly algorithm (FA by controlling the amplitude and phase excitation of array elements. A fitness function in the form of template has been formulated to obtain the error between original (pre-failed side lobe pattern and measured side lobe pattern and this error function has been minimized using FA. Numerical example of element failure correction of element failure of array along with multiple nulls is presented to show the capability of this flexible approach.Defence Science Journal, 2014, 64(2, pp. 136-142. DOI: http://dx.doi.org/10.14429/dsj.64.4250

  13. Integrated patch and slot array antenna for terahertz quantum cascade lasers at 4.7 THz

    Energy Technology Data Exchange (ETDEWEB)

    Bonzon, C., E-mail: bonzonc@phys.ethz.ch; Benea Chelmus, I. C.; Ohtani, K.; Geiser, M.; Beck, M.; Faist, J. [Institute for Quantum Electronics, ETH-Zürich, CH-8093 Zürich (Switzerland)

    2014-04-21

    Our work presents a slot and a patch array antenna at the front facet of a 4.7 THz quantum cascade laser as extractor, decreasing the facet reflectivity down to 2.6%. The resulting output power increases by a factor 2 and the slope efficiency by a factor 4. The simulated and the measured far-fields are in good agreement.

  14. A method for detection of deformations in large phase array antennas for spaceborne synthetic aperture radars

    Science.gov (United States)

    Li, F. K.

    1984-01-01

    A method to measure deformations in large, planar phased array antennas used in spaceborne synthetic aperture radars (SAR) is described. This method has the advantages that the deformation measurements can be performed anywhere in orbit and that no additional sensor is required. Indirect test results using the SEASAT SAR data indicate that this technique can detect deformations of small fractions of a wavelength.

  15. 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.

  16. Design of Vivaldi antenna array with end-fire beam steering function for 5G mobile terminals

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    This manuscript proposes a new design of phased array antenna for future fifth generation (5G) cellular communications. The proposed phased array antenna is designed on a low-cost N9000 PTFE substrate with overall size of 60×120×0.8 mm3. It consists of eight 28-GHz Vivaldi antenna elements used to...... characteristics in the entire operation band, which makes it suitable for millimeter-wave 5G communications. In addition, the performance of the antenna in the vicinity of user’s hand has been investigated in this study....

  17. Optimized Hyper Beamforming of Linear Antenna Arrays Using Collective Animal Behaviour

    Directory of Open Access Journals (Sweden)

    Gopi Ram

    2013-01-01

    Full Text Available A novel optimization technique which is developed on mimicking the collective animal behaviour (CAB is applied for the optimal design of hyper beamforming of linear antenna arrays. Hyper beamforming is based on sum and difference beam patterns of the array, each raised to the power of a hyperbeam exponent parameter. The optimized hyperbeam is achieved by optimization of current excitation weights and uniform interelement spacing. As compared to conventional hyper beamforming of linear antenna array, real coded genetic algorithm (RGA, particle swarm optimization (PSO, and differential evolution (DE applied to the hyper beam of the same array can achieve reduction in sidelobe level (SLL and same or less first null beam width (FNBW, keeping the same value of hyperbeam exponent. Again, further reductions of sidelobe level (SLL and first null beam width (FNBW have been achieved by the proposed collective animal behaviour (CAB algorithm. CAB finds near global optimal solution unlike RGA, PSO, and DE in the present problem. The above comparative optimization is illustrated through 10-, 14-, and 20-element linear antenna arrays to establish the optimization efficacy of CAB.

  18. Coherent Sources Direction Finding and Polarization Estimation with Various Compositions of Spatially Spread Polarized Antenna Arrays

    CERN Document Server

    Yuan, Xin

    2014-01-01

    Various compositions of sparsely polarized antenna arrays are proposed in this paper to estimate the direction-of-arrivals (DOAs) and polarizations of multiple coherent sources. These polarized antenna arrays are composed of one of the following five sparsely-spread sub-array geometries: 1) four spatially-spread dipoles with three orthogonal orientations, 2) four spatially-spread loops with three orthogonal orientations, 3) three spatially-spread dipoles and three spatially-spread loops with orthogonal orientations, 4) three collocated dipole-loop pairs with orthogonal orientations, and 5) a collocated dipole-triad and a collocated loop-triad. All the dipoles/loops/pairs/triads in each sub-array can also be sparsely spaced with the inter-antenna spacing far larger than a half-wavelength. Only one dimensional spatial-smoothing is used in the proposed algorithm to derive the two-dimensional DOAs and polarizations of multiple cross-correlated signals. From the simulation results, the sparse array composed of dip...

  19. Zero-bias microwave detectors based on array of nanorectifiers coupled with a dipole antenna

    Science.gov (United States)

    Kasjoo, Shahrir R.; Singh, Arun K.; Mat Isa, Siti S.; Ramli, Muhammad M.; Mohamad Isa, Muammar; Ahmad, Norhawati; Mohd Nor, Nurul I.; Khalid, Nazuhusna; Song, Ai Min

    2016-04-01

    We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as the self-switching diodes (SSDs). The large array was realized in a single lithography step without the need of interconnection layers, hence allowing for a simple and low-cost fabrication process. The SSD array was coupled with a narrowband dipole antenna with a resonant frequency of 890 MHz, to form a simple rectenna (rectifying antenna). The extrinsic voltage responsivity and noise-equivalent-power (NEP) of the rectenna were ∼70 V/W and ∼0.18 nW/Hz1/2, respectively, measured in the far-field region at unbiased condition. Nevertheless, the estimated intrinsic voltage responsivity can achieve up to ∼5 kV/W with NEP of ∼2.6 pW/Hz1/2.

  20. Beam Switching Cylindrical Array Antenna System for Communication

    Directory of Open Access Journals (Sweden)

    V. C. Misra

    1998-10-01

    Full Text Available The beam switching cylindrical array, which is a unique system, has been designed and developed to cover 360° in azimuth plane by generating 16 beams with specified elevation coverage.In this design, the concept of fast aperture selection (4 x 4 in microseconds from the total cylindrical array has been realised successfully to meet the requirement of point-to-multipoint communication. The components of the array, viz., radiating elements, powder dividers, switches, etc., are designed in printed circuit type, and hence, objectives of lightweight and ease of reproducibility are achieved. The lightweight of the array makes it accessible for easy mounting at a specified height for achieving longer communication range. Finally, a low-loss radome is incorporated to protect the array from environmental conditions. The various parameters, viz., return loss, gain, and switched-beam radiation patterns were measured over a bandwidth of 300 MHz in L- band and typical measured results are presented in this paper.

  1. GA BASED SYNTHESIS OF SATELLITE-BORNE MULTI-BEAM PLANAR ARRAY WITH ARBITRARY GEOMETRY

    Institute of Scientific and Technical Information of China (English)

    Jin Jun; Wang Huali; Zhu Wenming; Liu Yunzhi

    2006-01-01

    A planar array antenna with arbitrary geometry synthesis technique based on genetic algorithm is discussed. This approach avoids coding/decoding and directly works with complex numbers to simplify computing program and to speed up computation. This approach uses two crossover operators that can overcome premature convergence and the dependence of convergence on initial population. Simulation results show that this method is capable of synthesizing complex pattern shapes of planar arrays with arbitrary geometry and can realize good sidelobe suppression at the same time.

  2. Modelling of the dispersion coefficient for the optical beamforming for phased array antennas

    Science.gov (United States)

    Madziar, Krzysztof M.; Dawidczyk, Jarosław

    2006-10-01

    Phased array antennas have received an attention in radiolocation and radar technology due to the fact that there is no need for the physical movement of an antenna and a very fast angle shift of the beam is possible. The need for improving performance in such devices lead to use the optical beamforming. In order to design such system the usage of appropriate dispersion coefficient of time delay lines is required. This paper shows examples of such dispersion coefficient modeling together with possible and useful simplifications.

  3. Narrowband direction of arrival estimation for antenna arrays

    CERN Document Server

    Foutz, Jeffrey

    2008-01-01

    This book provides an introduction to narrowband array signal processing, classical and subspace-based direction of arrival (DOA) estimation with an extensive discussion on adaptive direction of arrival algorithms. The book begins with a presentation of the basic theory, equations, and data models of narrowband arrays. It then discusses basic beamforming methods and describes how they relate to DOA estimation. Several of the most common classical and subspace-based direction of arrival methods are discussed. The book concludes with an introduction to subspace tracking and shows how subspace tr

  4. X-band printed phased array antennas using high-performance CNT/ion gel/Ag transistors

    Science.gov (United States)

    Grubb, Peter M.; Bidoky, Fazel; Mahajan, Ankit; Subbaraman, Harish; Li, Wentao; Frisbie, Daniel; Chen, Ray T.

    2016-05-01

    This paper reports a fully printed phased array antenna developed on a 125 micron thick flexible Kapton substrate. Switching for the phase delay lines is accomplished using printed carbon nanotube transistors with ion gel dielectric layers. Design of each element of the phased array antenna is reported, including a low loss constant impedance power divider, a phase shifter network, and patch antenna design. Steering of an X-band PAA operating at 10GHz from 0 degrees to 22.15 degrees is experimentally demonstrated. In order to completely package the array with electrical interconnects, a single substrate interconnect scheme is also investigated.

  5. Certain investigations on the reduction of side lobe level of an uniform linear antenna array using biogeography based optimization technique with sinusoidal migration model and simplified-BBO

    Indian Academy of Sciences (India)

    T S Jeyali Laseetha; R Sukanesh

    2014-02-01

    In this paper, we propose biogeography based optimization technique, with linear and sinusoidal migration models and simplified biogeography based optimization (S-BBO), for uniformly spaced linear antenna array synthesis to maximize the reduction of side lobe level (SLL). This paper explores biogeography theory. It generalizes two migration models in BBO namely, linear migration model and sinusoidal migration model. The performance of SLL reduction in ULA is investigated. Our performance study shows that among the two, sinusoidal migration model is a promising candidate for optimization. In our work, simplified – BBO algorithmis also deployed. This determines an optimum set value for amplitude excitations of antenna array elements that generate a radiation pattern with maximum side lobe level reduction. Our detailed investigation also shows that sinusoidal migration model of BBO performs better compared to the other evolutionary algorithms discussed in this paper.

  6. A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array for C-Band Applications

    Directory of Open Access Journals (Sweden)

    Stefano Maddio

    2015-01-01

    Full Text Available A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in the C-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2. Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.

  7. Dual polarized receiving steering antenna array for measurement of ultrawideband pulse polarization structure

    Science.gov (United States)

    Balzovsky, E. V.; Buyanov, Yu. I.; Koshelev, V. I.; Nekrasov, E. S.

    2016-03-01

    To measure simultaneously two orthogonal components of the electromagnetic field of nano- and subnano-second duration, an antenna array has been developed. The antenna elements of the array are the crossed dipoles of dimension 5 × 5 cm. The arms of the dipoles are connected to the active four-pole devices to compensate the frequency response variations of a short dipole in the frequency band ranging from 0.4 to 4 GHz. The dipoles have superimposed phase centers allowing measuring the polarization structure of the field in different directions. The developed antenna array is the linear one containing four elements. The pattern maximum position is controlled by means of the switched ultrawideband true time delay lines. Discrete steering in seven directions in the range from -40° to +40° has been realized. The error at setting the pattern maximum position is less than 4°. The isolation of the polarization exceeds 29 dB in the direction orthogonal to the array axis and in the whole steering range it exceeds 23 dB. Measurement results of the polarization structure of radiated and scattered pulses with different polarization are presented as well.

  8. Dual polarized receiving steering antenna array for measurement of ultrawideband pulse polarization structure.

    Science.gov (United States)

    Balzovsky, E V; Buyanov, Yu I; Koshelev, V I; Nekrasov, E S

    2016-03-01

    To measure simultaneously two orthogonal components of the electromagnetic field of nano- and subnano-second duration, an antenna array has been developed. The antenna elements of the array are the crossed dipoles of dimension 5 × 5 cm. The arms of the dipoles are connected to the active four-pole devices to compensate the frequency response variations of a short dipole in the frequency band ranging from 0.4 to 4 GHz. The dipoles have superimposed phase centers allowing measuring the polarization structure of the field in different directions. The developed antenna array is the linear one containing four elements. The pattern maximum position is controlled by means of the switched ultrawideband true time delay lines. Discrete steering in seven directions in the range from -40° to +40° has been realized. The error at setting the pattern maximum position is less than 4°. The isolation of the polarization exceeds 29 dB in the direction orthogonal to the array axis and in the whole steering range it exceeds 23 dB. Measurement results of the polarization structure of radiated and scattered pulses with different polarization are presented as well. PMID:27036799

  9. High-Gain Textile Antenna Array System for Off-Body Communication

    Directory of Open Access Journals (Sweden)

    Maria Lucia Scarpello

    2012-01-01

    Full Text Available A novel high-gain textile antenna array system, fully integrated into a rescue-worker’s vest and operating in the Industrial, Scientific, and Medical wireless band (2.4–2.4835 GHz, is presented. The system comprises an array consisting of four tip-truncated equilateral triangular microstrip patch antennas (ETMPAs, a power divider, line stretchers, and coaxial cables. The array is vertically positioned on the human torso to produce a narrow beam in elevation, as such reducing fading and allowing to steer the maximum gain in a small angular sector centered around the broadside direction. To allow simple low-cost beam steering, we specifically minimize mutual coupling by using a relative large distance between the patches and by selecting the ETMPA element as the most suited topology from three potential patch geometries. Moreover, we investigate the stability of return loss and mutual coupling characteristics under different relative humidity conditions, when bending the array, when placing the system on-body, and when covering it by different textile layers. Reflection coefficient and gain patterns are simulated and measured for the antenna system in free space and placed on the human body.

  10. Measuring Noise Temperatures of Phased-Array Antennas for Astronomy at CSIRO

    CERN Document Server

    Chippendale, Aaron; Hay, Stuart

    2014-01-01

    We describe the development of a noise-temperature testing capability for phased-array antennas operating in receive mode from 0.7 GHz to 1.8 GHz. Sampled voltages from each array port were recorded digitally as the zenith-pointing array under test was presented with three scenes: (1) a large microwave absorber at ambient temperature, (2) the unobstructed radio sky, and (3) broadband noise transmitted from a reference antenna centred over and pointed at the array under test. The recorded voltages were processed in software to calculate the beam equivalent noise temperature for a maximum signal-to-noise ratio beam steered at the zenith. We introduced the reference-antenna measurement to make noise measurements with reproducible, well-defined beams directed at the zenith and thereby at the centre of the absorber target. We applied a detailed model of cosmic and atmospheric contributions to the radio sky emission that we used as a noise-temperature reference. We also present a comprehensive analysis of measureme...

  11. First results of the Standalone Antenna Array of the CODALEMA Radio Detection Experiment

    CERN Document Server

    A, Belletoile

    2011-01-01

    CODALEMA is one of the pioneer experiments dedicated to the recent field of cosmic ray radio detection. It is located at the radio observatory of Nancay (France). The detector setup combined until recently a ground particle detector and an array of active dipole antennas covering a total area of 0.25 km^2. The experiment is now going through a major upgrade with the deployment around the existing apparatus of a Standalone Antenna Array, which consists of 60 standalone new generation radio-detection stations and which will cover an area of 1.5 km^2 (33 stations deployed over the spring of 2011 and 27 stations to be deployed in late 2011). This new setup is intended to tackle the remaining unknowns of extensive air shower radio detection so as to make this technique a reliable and mature tool for Ultra High Energy Cosmic Ray (UHECR) physics. The latest results from the original CODALEMA array are discussed together with the first results of the Standalone Antenna Array.

  12. SUB-DOMAIN MOM FORMULATION FOR CIRCULAR AND NON-CIRCULAR LOOP ANTENNA ARRAYS

    Directory of Open Access Journals (Sweden)

    TOMÁŠ PÁLENÍK

    2011-05-01

    Full Text Available The method of moments (MoM analysis of thin-wire loop antenna arrays with multiple elements is presented in this paper. The proposed formulation provides simple algorithmic implementation that canbe applied to circular loop arrays as well as more generally shaped arrays using the Pocklington’s integral equation with simplified kernel for arbitrary shaped wires in combination with a superquadriccurve representation. This analysis leads to knowledge of the current distribution, input impedance and other electromagnetic properties of both uniform and non-uniform loop arrays. Numerical results areincluded to exhibit good agreement with various relevant references and simulation software. The data for large square and rectangular loop arrays are presented for the first time in literature.

  13. Dual Circularly Polarized Omnidirectional Antenna with Slot Array on Coaxial Cylinder

    Directory of Open Access Journals (Sweden)

    Bin Zhou

    2015-01-01

    Full Text Available A dual circularly polarized (CP omnidirectional antenna based on slot array in coaxial cylinder structure is presented in this paper. It is constructed by perpendicular slot pairs around and along the axis of the coaxial cylinder to realize the omnidirectional CP property, and two ports are assigned in its two sides as left hand circularly polarized (LHCP port and right hand circularly polarized (RHCP port, respectively. The proposed antenna achieves a bandwidth of 16.4% ranging from 5.05 to 5.95 GHz with an isolation higher than 15 dB between the two CP ports, and the return loss (RL is higher than 10 dB within the bandwidth in both of the two ports. From the measured results, the average axial ratio (AR of the proposed antenna in omnidirectional plane is lower than 1.5 dB.

  14. A Multibeam Dual-Band Orthogonal Linearly Polarized Antenna Array for Satellite Communication on the Move

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2015-01-01

    Full Text Available The design and simulation of a 10 × 8 multibeam dual-band orthogonal linearly polarized antenna array operating at Ku-band are presented for transmit-receive applications. By using patches with different coupling methods as elements, both perpendicular polarization in 12.25–12.75 GHz band and horizontal polarization in 14.0–14.5 GHz band are realized in a shared antenna aperture. A microstrip Rotman lens is employed as the beamforming network with 7 input ports, which can generate a corresponding number of beams to cover −30°–30° with 5 dB beamwidth along one dimension. This type of multibeam orthogonal linearly polarized planar antenna is a good candidate for satellite communication (SatCom.

  15. The Effect of Mutual Coupling on a High Altitude Platform Diversity System Using Compact Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Tommy Hult

    2010-01-01

    Full Text Available We analyze the destructive effects of mutual coupling and spatial correlation between the separate antenna elements on a combined diversity system consisting of multiple HAPs (High-Altitude Platforms employing various compact MIMO (Multiple-Input Multiple-Output antenna array configurations, in order to enhance the mutual information in HAP communication links. In addition, we assess the influence of the separation angle between HAPs on system performance, and determine the optimal separation angles that maximize the total mutual information of the system for various compact MIMO antennas. Simulation results show that although the mutual information is degraded by mutual coupling and spatial correlation, the proposed HAP diversity system still provides better performance compared to a nondiversity system for all tested scenarios.

  16. Performance Analysis of Blind Beamforming Algorithms in Adaptive Antenna Array in Rayleigh Fading Channel Model

    International Nuclear Information System (INIS)

    In this paper, we analyze the performance of adaptive blind algorithms – i.e. Kaiser Constant Modulus Algorithm (KCMA), Hamming CMA (HAMCMA) – with CMA in a wireless cellular communication system using digital modulation technique. These blind algorithms are used in digital signal processor of adaptive antenna to make it smart and change weights of the antenna array system dynamically. The simulation results revealed that KCMA and HAMCMA provide minimum mean square error (MSE) with 1.247 dB and 1.077 dB antenna gain enhancement, 75% reduction in bit error rate (BER) respectively over that of CMA. Therefore, KCMA and HAMCMA algorithms give a cost effective solution for a communication system

  17. Enhancing resolution properties of array antennas via field extrapolation: application to MIMO systems

    Science.gov (United States)

    Reggiannini, Ruggero

    2015-12-01

    This paper is concerned with spatial properties of linear arrays of antennas spaced less than half wavelength. Possible applications are in multiple-input multiple-output (MIMO) wireless links for the purpose of increasing the spatial multiplexing gain in a scattering environment, as well as in other areas such as sonar and radar. With reference to a receiving array, we show that knowledge of the received field can be extrapolated beyond the actual array size by exploiting the finiteness of the interval of real directions from which the field components impinge on the array. This property permits to increase the performance of the array in terms of angular resolution. A simple signal processing technique is proposed allowing formation of a set of beams capable to cover uniformly the entire horizon with an angular resolution better than that achievable by a classical uniform-weighing half-wavelength-spaced linear array. Results are also applicable to active arrays. As the above approach leads to arrays operating in super-directive regime, we discuss all related critical aspects, such as sensitivity to external and internal noises and to array imperfections, and bandwidth, so as to identify the basic design criteria ensuring the array feasibility.

  18. A planar array antenna for TV broadcasting communications

    Science.gov (United States)

    Cucci, A.; de Luca, A.

    The L-Sat planar array for satellite direct TV broadcasting is described. Still in the design stage, the array is intended for broadcasting on the X-band, within the 0.98 x 2.3 deg elliptical beam, sidelobe below -30 dB, circular polarization with low cross-polarization WARC requirements. The results of an analysis of the effects produced by the contour profile on the radiation pattern are presented. Further work has proceeded on a circuit model of a slot in a single subarray, the coupling of mutual slots, and the phase and amplitude behhavior of the coupled feeding and radiating waveguides. Finally, simulations have been performed of the thermally induced deformations, with attention given to warping and a tilted half-plane.

  19. System for tunerless operation of a four-element phased array antenna for fast wave current drive

    International Nuclear Information System (INIS)

    A simple transmission line configuration for powering a four-element phased antenna array is described. This system, called the balanced feed configuration (BFC) is suitable for co- or counter- Fast Wave Current Drive (FWCD) applications. It has the property of presenting a constant matched load to the transmitter despite wide variations in the antenna load impedance without the use of variable tuning elements. This system has been implemented on a 2 MW 60 MHz FWCD antenna on the DIII-D tokamak

  20. Self-calibration of Antenna Errors Using Focal Plane Arrays

    Science.gov (United States)

    Napier, P. J.; Cornwell, T. J.

    The thery of focal-plane correlation is reviewed and applied to the problem of the self-calibration and self-correction of a radio telescope with errors in its reflecting surface. Curves are presented which allow the estimation of focal-plane array size and integration time needed for telescopes with varying amounts of error. It is suggested that the technique may have application to the problem of the construction of large telescopes in space.

  1. A passive array antenna system for microwave imaging applications

    International Nuclear Information System (INIS)

    In this paper a 3-GHz imaging system based on a modulated scattering technique (MST) is described. By using a probe made of an array of (passive) dipoles rotating around a test area, it is possible to efficiently measure field-scattered data under approximately transverse-magnetic illumination conditions. In the paper, the functional description of system is provided together with some preliminary validation tests

  2. Synthesis Array Topology Metrics in Location Characterization

    Science.gov (United States)

    Shanmugha Sundaram, GA

    2015-08-01

    Towards addressing some of the fundamental mysteries in physics at the micro- and macro-cosm level, that form the Key Science Projects (KSPs) for the Square Kilometer Array (SKA; such as Probing the Dark Ages and the Epoch of Reionization in the course of an Evolving Universe; Galaxy Evolution, Cosmology, and Dark Energy; and the Origin and evolution of Cosmic Magnetism) a suitable interfacing of these goals has to be achieved with its optimally designed array configuration, by means of a critical evaluation of the radio imagingcapabilities and metrics. Of the two forerunner sites, viz. Australia and South Africa, where pioneering advancements to state-of-the-art in synthesis array radio astronomy instrumentation are being attempted in the form of pathfinders to the SKA, for its eventual deployment, a diversity of site-dependent topology and design metrics exists. Here, the particular discussion involves those KSPs that relate to galactic morphology and evolution, and explores their suitability as a scientific research goal from the prespective of the location-driven instrument design specification. Relative merits and adaptability with regard to either site shall be presented from invoking well-founded and established array-design and optimization principles designed into a customized software tool.

  3. Development of patch array antenna for noncontract moisture measurement at microwave frequencies

    International Nuclear Information System (INIS)

    This study was conducted to develop an antenna for noncontact measurement of moisture content in powdered food using microwave free space transmission technique. Attenuation and phase of transmitted microwave signal through milk powder samples having various moisture contents were measured using hem antenna and network analyzer at microwave frequencies. As a measuring frequency for moisture content, X band frequency was selected. A pair of light and simple micro-strip patch array antenna for measurement of grain moisture content is designed and implemented on a Teflon substrate with relative dielectric constant of 2.6 and thickness of 0.54 mm by using Ensemble ver, 4.02 software. The aperture of micro-strip patch arrays is 41 mm width and 24 mm height. The characteristics of micro-strip patch antenna such as gain, return loss, and bandwidth are 11.35 dBi, -29 dB and 0.35 GHz( at far-field pattern of E and H plane.

  4. An L-Band, Circularly Polarised, Dual-Feed, Cavity-Backed Annular Slot Antenna For Phased-Array Applications

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2006-01-01

    The results of a parametric study for the development of an L-band, circularly polarised, dual-feed, cavity-backed annular slot antenna is presented. The study included detailed numerical simulations and measurements on a prototype with different ground planes, to assess the antenna’s applicability...... as an element in a small phased array antenna....

  5. Design and performance of acoustic planar array antenna for Doppler sodar

    Directory of Open Access Journals (Sweden)

    A.Kamalakumari

    2012-09-01

    Full Text Available The remote probing of the thermal structure and the wind velocity in the lower atmosphere requires highly directive antennas, which should have a half-power beam width of about ±10° (3-dB points, a 90°-sidelobe suppression of at least 40 dB, little volume reverberation, low wind sensitivity, and be made of weatherproofmaterial. In this paper, various off-axis planar antennas have been built and acoustically evaluated the design aspects, measured results and field patterns of an 8x8 acoustic planar array antennas are described. Tweeter elements are arranged in a planar geometry and are capable of transmitting vertical polarization when placed nearly horizontal, are appropriate for the sodar applications. The performance of 8x8 planar antennas are tested experimentally for the frequencies from 1.8KHz to 4KHz at elevation angles ranging between 0 to 180°.The experimental results, as well as the measured beam widths and field patterns of this antennas, are presented.

  6. Frequency translating phase conjugation circuit for active retrodirective antenna array. [microwave transmission

    Science.gov (United States)

    Chernoff, R. (Inventor)

    1980-01-01

    An active retrodirective antenna array which has central phasing from a reference antenna element through a "tree" structured network of transmission lines utilizes a number of phase conjugate circuits (PCCs) at each node and a phase reference regeneration circuit (PRR) at each node except the initial node. Each node virtually coincides with an element of the array. A PCC generates the exact conjugate phase of an incident signal using a phase locked loop which combines the phases in an up converter, divides the sum by 2 and mixes the result with the phase in a down converter for phase detection. The PRR extracts the phase from the conjugate phase. Both the PCC and the PRR are not only exact but also free from mixer degeneracy.

  7. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA)

    Science.gov (United States)

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  8. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA).

    Science.gov (United States)

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  9. Superconducting Quantum Arrays for Wideband Antennas and Low Noise Amplifiers

    Science.gov (United States)

    Mukhanov, O.; Prokopemko, G.; Romanofsky, Robert R.

    2014-01-01

    Superconducting Quantum Iinetference Filters (SQIF) consist of a two-dimensional array of niobium Josephson Junctions formed into N loops of incommensurate area. This structure forms a magnetic field (B) to voltage transducer with an impulse like response at B0. In principle, the signal-to-noise ratio scales as the square root of N and the noise can be made arbitrarily small (i.e. The SQIF chips are expected to exhibit quantum limited noise performance). A gain of about 20 dB was recently demonstrated at 10 GHz.

  10. The impact of Antenna Pattern Frequency Dependence in Aperture Synthesis Microwave Radiometers

    OpenAIRE

    Camps Carmona, Adriano José; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Martín Neira, Manuel

    2005-01-01

    The effect of the frequency dependence of the antenna voltage patterns within the bandwidth of an aperture synthesis interferometric radiometer is studied and quantified using actual antenna voltage patterns measured at different frequencies for the first nine receivers of the Microwave Imaging Radiometer with Aperture Synthesis instrument aboard the European Space Agency's Soil Moisture and Ocean Salinity mission. A technique is proposed to mitigate this effect.

  11. A Novel Miniaturized Dual Slant-Polarized UWB Antenna Array with Excellent Pattern Symmetry Property for MIMO Applications

    Directory of Open Access Journals (Sweden)

    Zhi Zeng

    2015-01-01

    Full Text Available A novel miniaturized 1 × 10 uniform linear dual slant-polarized UWB antenna array for MIMO base station is presented. The antenna array operates in the frequency band from 1710 to 2690 MHz with a 17.3–18.7 dBi gain in a size of 105 × 1100 × 37 mm. The array element is composed of two single-polarized dipoles evolved from bow-tie antenna with slots on them, which miniaturize the size of the antenna. The 10 array elements are fed through an air dielectric strip-line power splitter. Two parameters, the beam tracking and the beam squint, are presented to quantitatively describe the pattern symmetry property of the antenna. The simulated and measured radiation performances are studied and compared. The results show that the pattern symmetry property of the single antenna element has been improved about 24% compared with the former study, and the antenna array also provides excellent pattern symmetry property.

  12. Performance Analysis of Space Diversity Steerable Beam Smart Antenna S-ALOHA with Arrays

    OpenAIRE

    Soni, PM; Chockalingam, A

    2000-01-01

    We analyze the throughput, delay and energy efficiency performance of space diversity slotted ALOHA when multibeam smart antenna arrays capable of steering the beams selectively on smaller sectors, are used at the base station receiver. Analytical expressions to establish the effect of different beamwidths, number of beams, beam steering patterns, and beam service times on the achieved performance of S-ALOHA an derived. We show that under high load conditions steered beams with long beam serv...

  13. Generation of OAM Radio Waves with Three Polarizations Using Circular Horn Antenna Array

    OpenAIRE

    2015-01-01

    This paper provides an effective solution of generating OAM-carrying radio beams with all three polarizations: the linear, the left-hand circular, and the right-hand circular polarizations. Through reasonable configuration of phased antenna array using elements with three polarizations, the OAM radio waves with three polarizations for different states can be generated. The vectors of electric fields with different OAM states for all three polarizations are presented and analyzed in detail. Th...

  14. Applications of Generalized Cascade Scattering Matrix on the Microwave Circuits and Antenna Arrays

    OpenAIRE

    2015-01-01

    The ideal lossless symmetrical reciprocal network (ILSRN) is constructed and introduced to resolve the complex interconnections of two arbitrary microwave networks. By inserting the ILSRNs, the complex interconnections can be converted into the standard one-by-one case without changing the characteristics of the previous microwave networks. Based on the algorithm of the generalized cascade scattering matrix, a useful derivation on the excitation coefficients of antenna arrays is firstly propo...

  15. Opto-microwave technique in the promising active phased antenna arrays

    OpenAIRE

    Bakhrakh, Lev D.; Shifrin, Yakov S.

    1995-01-01

    Implementation of multi-element active phased antenna arrays (APAA) due to poor mass-overall dimensions characteristics, signals distribution system complexity is rather difficult. Extra difficulties arise with wide-band signals and millimeter waves APAA. The signal distribution fiber-optical systems using elements of laser technique and other elements of opto-electronics allow in many cases to solve completely the problem of the signals distribution system and pilot and monitor signals in AP...

  16. Simulation of Airborne Antenna Array Layout Problems Using Parallel Higher-Order MoM

    OpenAIRE

    Zhongchao Lin; Yu Zhang; Shugang Jiang; Xunwang Zhao; Jingyan Mo

    2014-01-01

    The parallel higher-order Method of Moments based on message passing interface (MPI) has been successfully used to analyze the changes in radiation patterns of a microstrip patch array antenna mounted on different positions of an airplane. The block-partitioned scheme for the large dense MoM matrix and a block-cyclic matrix distribution scheme are designed to achieve excellent load balance and high parallel efficiency. Numerical results demonstrate that the rigorous parallel Method of Moments...

  17. Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems

    Science.gov (United States)

    Avser, Bilgehan

    The thesis presents three dual-band frequency tunable antennas for carrier aggregation systems and two new feeding networks for reducing the number of phase shifters in limited-scan arrays. First, single- and dual-feed, dual-frequency, low-profile antennas with independent frequency tuning using varactor diodes are presented. The dual-feed planar inverted F-antenna (PIFA) has two operating frequencies which are independently tuned at 0.7--1.1 GHz and at 1.7--2.3 GHz with better than 10 dB impedance match. The isolation between the high-band and the low-band ports is > 13 dB; hence, one resonant frequency can be tuned without affecting the other. The single-feed contiguous-dual-band antenna has two resonant frequencies, which are independently tuned at 1.2--1.6 GHz at 1.6--2.3 GHz with better than 10 dB impedance match for most of the tuning range. And the single-feed dual-band antenna has two resonant frequencies, which are independently tuned at 0.7--1.0 GHz at 1.7--2.3 GHz with better than 10 dB impedance match for most of the tuning range. The tuning is done using varactor diodes with a capacitance range from 0.8 to 3.8 pF, which is compatible with RF MEMS devices. The antenna volumes are 63 x 100 x 3.15 mm3 on epsilon r = 3.55 substrates and the measured antenna efficiencies vary between 25% and 50% over the tuning range. The application areas are in carrier aggregation systems for fourth generation (4G) wireless systems. Next, a new phased array feeding network that employs random sequences of non-uniform sub-arrays (and a single phase shifter for each sub-array) is presented. When these sequences are optimized, the resulting phased arrays can scan over a wide region with low sidelobe levels. Equations for analyzing the random arrays and an algorithm for optimizing the array sequences are presented. Multiple random-solutions with different number of phase shifters and different set of sub-array groups are analyzed and design guidelines are presented. The

  18. Measured Sensitivity of the First Mark II Phased Array Feed on an ASKAP Antenna

    CERN Document Server

    Chippendale, A P; Beresford, R J; Hampson, G A; Macleod, A; Shaw, R D; Brothers, M L; Cantrall, C; Forsyth, A R; Hay, S G; Leach, M

    2015-01-01

    This paper presents the measured sensitivity of CSIRO's first Mk. II phased array feed (PAF) on an ASKAP antenna. The Mk. II achieves a minimum system-temperature-over-efficiency $T_\\mathrm{sys}/\\eta$ of 78 K at 1.23 GHz and is 95 K or better from 835 MHz to 1.8 GHz. This PAF was designed for the Australian SKA Pathfinder telescope to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array (SKA).

  19. Spatio-Temporal Equalizer for a Receiving-Antenna Feed Array

    Science.gov (United States)

    Mukai, Ryan; Lee, Dennis; Vilnrotter, Victor

    2010-01-01

    A spatio-temporal equalizer has been conceived as an improved means of suppressing multipath effects in the reception of aeronautical telemetry signals, and may be adaptable to radar and aeronautical communication applications as well. This equalizer would be an integral part of a system that would also include a seven-element planar array of receiving feed horns centered at the focal point of a paraboloidal antenna that would be nominally aimed at or near the aircraft that would be the source of the signal that one seeks to receive (see Figure 1). This spatio-temporal equalizer would consist mostly of a bank of seven adaptive finite-impulse-response (FIR) filters one for each element in the array - and the outputs of the filters would be summed (see Figure 2). The combination of the spatial diversity of the feedhorn array and the temporal diversity of the filter bank would afford better multipath-suppression performance than is achievable by means of temporal equalization alone. The seven-element feed array would supplant the single feed horn used in a conventional paraboloidal ground telemetry-receiving antenna. The radio-frequency telemetry signals re ceiv ed by the seven elements of the array would be digitized, converted to complex baseband form, and sent to the FIR filter bank, which would adapt itself in real time to enable reception of telemetry at a low bit error rate, even in the presence of multipath of the type found at many flight test ranges.

  20. An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

    Science.gov (United States)

    D'Addario, Larry R.; Wang, Douglas

    2016-01-01

    Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. While the cost of most components of the telescope is proportional to the number of antennas N, the cost and power consumption of cross-correlationare proportional to N2 and dominate at sufficiently large N. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In a large system, each IC performs correlations for all pairs of antennas but for a portion of the telescope's bandwidth (the so-called "FX" structure). In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals (N=32 antennas with 2 opposite-polarization signals per antenna). When N is larger, the input data are buffered in an on-chipmemory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulated so as to obtain accurate estimates of the IC's size and power consumption. It isintended for fabrication in a 32 nm silicon-on-insulator process, where it will require less than 12mm2 of silicon area and achieve an energy efficiency of 1.76 to 3.3 pJ per CMAC operation, depending on the number of antennas. Operation has been analyzed in detail up to N = 4096. The system-level energy efficiency, including board-levelI/O, power supplies, and controls, is expected to be 5 to 7 pJ per CMAC operation. Existing correlators for the JVLA (N = 32) and ALMA (N = 64) telescopes achieve about 5000 pJ and 1000 pJ respectively usingapplication-specific ICs in older technologies. To our knowledge, the largest-N existing correlator is LEDA atN = 256; it

  1. An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

    Science.gov (United States)

    D’Addario, Larry R.; Wang, Douglas

    2016-03-01

    Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. While the cost of most components of the telescope is proportional to the number of antennas N, the cost and power consumption of cross-correlation are proportional to N2 and dominate at sufficiently large N. Here, we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In a large system, each IC performs correlations for all pairs of antennas but for a portion of the telescope’s bandwidth (the so-called “FX” structure). In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals (N=32 antennas with two opposite-polarization signals per antenna). When N is larger, the input data are buffered in an on-chip memory and the CMACs are reused as many times as needed to compute all correlations. The design has been synthesized and simulated so as to obtain accurate estimates of the ICs size and power consumption. It is intended for fabrication in a 32nm silicon-on-insulator process, where it will require less than 12mm2 of silicon area and achieve an energy efficiency of 1.76-3.3pJ per CMAC operation, depending on the number of antennas. Operation has been analyzed in detail up to N=4096. The system-level energy efficiency, including board-level I/O, power supplies, and controls, is expected to be 5-7pJ per CMAC operation. Existing correlators for the JVLA (N=32) and ALMA (N=64) telescopes achieve about 5000pJ and 1000pJ, respectively using application-specific ICs (ASICs) in older technologies. To our knowledge, the largest-N existing correlator is LEDA at N=256; it

  2. Design of On-Chip N-Fold Orbital Angular Momentum Multicasting Using V-Shaped Antenna Array

    Science.gov (United States)

    Du, Jing; Wang, Jian

    2015-01-01

    We design a V-shaped antenna array to realize on-chip multicasting from a single Gaussian beam to four orbital angular momentum (OAM) beams. A pattern search assisted iterative (PSI) algorithm is used to design an optimized continuous phase pattern which is further discretized to generate collinearly superimposed multiple OAM beams. Replacing the designed discrete phase pattern with corresponding V-shaped antennas, on-chip N-fold OAM multicasting is achieved. The designed on-chip 4-fold OAM multicasting exploiting V-shaped antenna array shows favorable operation performance with low crosstalk less than -15 dB. PMID:25951325

  3. Design of on-chip N-fold orbital angular momentum multicasting using V-shaped antenna array.

    Science.gov (United States)

    Du, Jing; Wang, Jian

    2015-01-01

    We design a V-shaped antenna array to realize on-chip multicasting from a single Gaussian beam to four orbital angular momentum (OAM) beams. A pattern search assisted iterative (PSI) algorithm is used to design an optimized continuous phase pattern which is further discretized to generate collinearly superimposed multiple OAM beams. Replacing the designed discrete phase pattern with corresponding V-shaped antennas, on-chip N-fold OAM multicasting is achieved. The designed on-chip 4-fold OAM multicasting exploiting V-shaped antenna array shows favorable operation performance with low crosstalk less than -15 dB. PMID:25951325

  4. Design and Development of Broadband Inverted E-shaped Patch Microstrip Array Antenna For 3G Wireless Network

    Directory of Open Access Journals (Sweden)

    Norbahiah Misran

    2008-01-01

    Full Text Available Microstrip patch antenna has been received tremendous attention since the last two decades and now it becomes a major component in the development of Smart Antenna System for Third-Generation Wireless Network proposed by the ITU-R under the banner of IMT-2000. Smart antenna consists of an array of antennas associated with it a base-band hardware and control unit (inclusive of the software algorithm that have the capability to change its radiation pattern according to the direction of the user. This paper describes the design and development of broadband Inverted E-shaped patch microstrip array antennas for 3G wireless network. The antenna was designed for the IMT-2000 operating frequency range of 1.885–2.200GHz and was built as an array of 4x4 inverted E-shaped patches. The beamforming feed network comprises of commercial variable attenuators (KAT1D04SA002, variable phase shifters (KPH35OSC000, and the corporate 16-ways Wilkinson power divider which was developed in-house. The antenna successfully achieves the bandwidth of 16.14% (at VSWR: 1.5 with respect to the center frequency of 2.045 GHz. The antenna is capable of scanning with the maximum scanning angle of ±30º and ±25º in azimuth and elevation respectively.

  5. An LTCC Based Compact SIW Antenna Array Feed Network for a Passive Imaging Radiometer

    KAUST Repository

    Abuzaid, Hattan

    2013-02-05

    Passive millimeter-wave (PMMW) imaging is a technique that allows the detection of inherent millimeter-wave radiation emitted by bodies. Since different bodies with varying properties emit unequal power intensities, a contrast can be established to detect their presence. The advantage of this imaging scheme over other techniques, such as optical and infrared imaging, is its ability to operate under all weather conditions. This is because the relatively long wavelengths of millimeter-waves, as compared to visible light, penetrate through clouds, fog, and sandstorms. The core of a PMMW camera is an antenna, which receives the electromagnetic radiation from a scene. Because PMMW systems require high gains to operate, large antenna arrays are typically employed. This mandatory increase of antenna elements is associated with a large feeding network. Therefore, PMMW cameras usually have a big profile. In this work, two enabling technologies, namely, Substrate integrated Waveguide (SIW) and Low Temperature Co-fired Ceramic (LTCC), are coupled with an innovative design to miniaturize the passive front-end. The two technologies synergize very well with the shielded characteristics of SIW and the high density multilayer integration of LTCC. The proposed design involves a novel multilayer power divider, which is incorporated in a folded feed network structure by moving between layers. The end result is an efficient feeding network, which footprint is least affected by an increase in array size. This is because the addition of more elements is accommodated by a vertical expansion rather than a lateral one. To characterize the feed network, an antenna array has been designed and integrated through efficient transitions.The complete structure has been simulated and fabricated. The results demonstrate an excellent performance, manifesting in a gain of 20 dBi and a bandwidth of more than 11.4% at 35 GHz. These values satisfy the general requirements of a PMMW system.

  6. Antenna-coupled TES bolometers used in BICEP2, Keck array, and SPIDER

    CERN Document Server

    Ade, P A R; Amiri, M; Barkats, D; Benton, S J; Bischoff, C A; Bock, J J; Bonetti, J A; Brevik, J A; Buder, I; Bullock, E; Chattopadhyay, G; Davis, G; Day, P K; Dowell, C D; Duband, L; Filippini, J P; Fliescher, S; Golwala, S R; Halpern, M; Hasselfield, M; Hildebrandt, S R; Hilton, G C; Hristov, V; Hui, H; Irwin, K D; Jones, W C; Karkare, K S; Kaufman, J P; Keating, B G; Kefeli, S; Kernasovskiy, S A; Kovac, J M; Kuo, C L; Leduc, H G; Leitch, E M; Llombart, N; Lueker, M; Mason, P; Megerian, K; Moncelsi, L; Netterfield, C B; Nguyen, H T; O'Brient, R; Ogburn, R W; Orlando, A; Pryke, C; Rahlin, A S; Reintsema, C D; Richter, S; Runyan, M C; Schwarz, R; Sheehy, C D; Staniszewski, Z K; Sudiwala, R V; Teply, G P; Tolan, J E; Trangsrud, A; Tucker, R S; Turner, A D; Vieregg, A G; Weber, A; Wiebe, D V; Wilson, P; Wong, C L; Yoon, K W; Zmuidzinas, J

    2015-01-01

    We have developed antenna-coupled transition-edge sensor (TES) bolometers for a wide range of cosmic microwave background (CMB) polarimetry experiments, including BICEP2, Keck Array, and the balloon borne SPIDER. These detectors have reached maturity and this paper reports on their design principles, overall performance, and key challenges associated with design and production. Our detector arrays repeatedly produce spectral bands with 20%-30% bandwidth at 95, 150, or 220~GHz. The integrated antenna arrays synthesize symmetric co-aligned beams with controlled side-lobe levels. Cross-polarized response on boresight is typically ~0.5%, consistent with cross-talk in our multiplexed readout system. End-to-end optical efficiencies in our cameras are routinely 35% or higher, with per detector sensitivities of NET~300 uKrts. Thanks to the scalability of this design, we have deployed 2560 detectors as 1280 matched pairs in Keck Array with a combined instantaneous sensitivity of ~9 uKrts, as measured directly from CMB...

  7. Circularly Polarized Microstrip Yagi Array Antenna with Wide Beamwidth and High Front-to-Back Ratio

    Directory of Open Access Journals (Sweden)

    Yun Hao

    2016-01-01

    Full Text Available A circularly polarized (CP Microstrip Yagi array antenna (MSYA is designed in order to achieve high front-to-back ratio R(F/B and high gain over wide range in the forward radiation space. A Wilkinson power divider owning two output ways with the same magnitude and different phase is used to feed the antenna. Parametric studies are carried out to investigate the effects of some key geometrical sizes on the antenna’s performance. A prototype of the antenna is fabricated, and good agreement between the measured results and the numerical simulations is observed. The overlap bandwidth of VSWR ≤ 1.5 and AR ≤ 3 dB is about 11%. The steering angle (α between the peak gain direction and the broadside can achieve 35°, R(F/B reaches 19 dB, and the gain at the front point (G0 is only 4.3 dB lower than the maximum gain (Gm. The antenna has a wide beamwidth CP radiation pattern over wide spatial range including 0° ≤ θ ≤ 90° in vertical plane and −35° ≤ φ ≤ 55° in horizontal plane.

  8. Theoretical study of two-element array of equilateral triangular patch microstrip antenna on ferrite substrate

    Indian Academy of Sciences (India)

    K K Verma; K R Soni

    2005-09-01

    The radiation characteristics of a two-element array of equilateral triangular patch microstrip antenna on a ferrite substrate are studied theoretically by considering the presence of bias magnetic field in the direction of propagation of electromagnetic waves. It is found that the natural modes of propagation in the direction of magnetic field are left- and right-circularly polarized waves and these modes have different propagation constants. In loss-less isotropic warm plasma, this array antenna geometry excites both electromagnetic (EM) and electroacoustic plasma (P) waves in addition to a nonradiating surface wave. In the absence of an external magnetic field, the EM- and P-waves can be decoupled into two independent modes, the electroacoustic mode is longitudinal while the electromagnetic mode is transverse. The far-zone EM-mode and P-mode radiation fields are derived using vector wave function techniques and pattern multiplication approaches. The results are obtained in both plasma medium and free space. Some important antenna parameters such as radiation conductance, directivity and quality factor are plotted for different values of plasma-to-source frequency.

  9. Modeling and optimization of the antenna system with focal plane array for the new generation radio telescopes with wide field of view

    CERN Document Server

    Iupikov, O

    2016-01-01

    The model of the reflector antenna system with focal plane array, low-noise amplifier and beamformer is developed in the work. The beamformer strategy is suggested to reduce the receiving sensitivity ripple inside field of view of the telescope, while the sensitivity itself drops slightly (less than 10%). The system APERTIF (which is currently under development in Netherlands Institute For Radioastronomy, ASTRON) has been analyzed using developed model, and numerical results are presented. The obtained numerical results have been verified experimentally in anechoic chamber as well as on one of the dishes of the Westerbork Synthesis Radio Telescope (all measurements have been done in ASTRON).

  10. Neural-genetic method for synthesis of antennas and microwave devices

    Directory of Open Access Journals (Sweden)

    F. F. Dubrovka

    2008-05-01

    Full Text Available A neural-genetic concept is proposed for synthesis of antennas and microwave devices. A device to be optimized is modeled by artificial neural networks and synthesis is made by genetic algorithm based inversion of the artificial neural networks.

  11. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    Science.gov (United States)

    Trichopoulos, Georgios C.

    The terahertz (THz) band provides unique sensing opportunities that enable several important applications such as biomedical imaging, remote non-destructive inspection of packaged goods, and security screening. THz waves can penetrate most materials and can provide unique spectral information in the 0.1--10 THz band with high resolution. In contrast, other imaging modalities, like infrared (IR), suffer from low penetration depths and are thus not attractive for non-destructive evaluation. However, state-of-the-art THz imaging systems typically employ mechanical raster scans using a single detector to acquire two-dimensional images. Such devices tend to be bulky and complicated due to the mechanical parts, and are thus rather expensive to develop and operate. Thus, large-format (e.g. 100x100 pixels) and all-electronics based THz imaging systems are badly needed to alleviate the space, weight and power (SWAP) factors and enable cost effective utilization of THz waves for sensing and high-data-rate communications. In contrast, photonic sensors are very compact because light can couple directly to the photodiode without residing to radiation coupling topologies. However, in the THz band, due to the longer wavelengths and much lower photon energies, highly efficient antennas with optimized input impedance have to be integrated with THz sensors. Here, we implement novel antenna engineering techniques that are optimized to take advantage of recent technological advances in solid-state THz sensing devices. For example, large-format focal plane arrays (FPAs) have been the Achilles' heel of THz imaging systems. Typically, optical components (lenses, mirrors) are employed in order to improve the optical performance of FPAs, however, antenna sensors suffer from degraded performance when they are far from the optical axis, thus minimizing the number of useful FPA elements. By modifying the radiation pattern of FPA antennas we manage to alleviate the off-axis aberration

  12. Phased array antenna matching: Simulation and optimization of a planar phased array of circular waveguide elements

    Science.gov (United States)

    Dudgeon, J. E.

    1972-01-01

    A computerized simulation of a planar phased array of circular waveguide elements is reported using mutual coupling and wide angle impedance matching in phased arrays. Special emphasis is given to circular polarization. The aforementioned computer program has as variable inputs: frequency, polarization, grid geometry, element size, dielectric waveguide fill, dielectric plugs in the waveguide for impedance matching, and dielectric sheets covering the array surface for the purpose of wide angle impedance matching. Parameter combinations are found which produce reflection peaks interior to grating lobes, while dielectric cover sheets are successfully employed to extend the usable scan range of a phased array. The most exciting results came from the application of computer aided optimization techniques to the design of this type of array.

  13. Field Deployment of Prototype Antenna Tiles for the Mileura Widefield Array--Low Frequency Demonstrator

    CERN Document Server

    Bowman, J D; Briggs, F H; Corey, B E; Lynch, M J; Bhat, N D R; Cappallo, R J; Doeleman, S S; Fanous, B J; Herne, D; Hewitt, J N; Johnston, C; Kasper, J C; Kocz, J; Kratzenberg, E; Lonsdale, C J; Morales, M F; Oberoi, D; Salah, J E; Stansby, B; Stevens, J; Torr, G; Wayth, R; Webster, R L; Wyithe, J S B; Bowman, Judd D.; Barnes, David G.; Briggs, Frank H.; Corey, Brian E.; Lynch, Merv J.; Cappallo, Roger J.; Doeleman, Sheperd S.; Fanous, Brian J.; Herne, David; Hewitt, Jacqueline N.; Johnston, Chris; Kasper, Justin C.; Kocz, Jonathon; Kratzenberg, Eric; Lonsdale, Colin J.; Morales, Miguel F.; Oberoi, Divya; Salah, Joseph E.; Stansby, Bruce; Stevens, Jamie; Torr, Glen; Wayth, Randall; Webster, Rachel L.

    2006-01-01

    Experiments were performed with prototype antenna tiles for the Mileura Widefield Array--Low Frequency Demonstrator (MWA-LFD) to better understand the widefield, wideband properties of their design and to characterize the radio frequency interference (RFI) between 80 and 300 MHz at the site in Western Australia. Observations acquired during the six month deployment confirmed the predicted sensitivity of the antennas, sky-noise dominated system temperatures, and phase-coherent interferometric measurements. The radio spectrum is remarkably free of strong terrestrial signals, with the exception of two narrow frequency bands allocated to satellite downlinks and rare bursts due to ground-based transmissions being scattered from aircraft and meteor trails. Results indicate the potential of the MWA-LFD to make significant achievements in its three key science objectives: epoch of reionziation science, heliospheric science, and radio transient detection.

  14. Parabolic antennas, and circular slot arrays, for the generation of Non-Diffracting Beams of Microwaves

    CERN Document Server

    Zamboni-Rached, Michel

    2014-01-01

    We propose in detail Antennas for generating Non-Diffracting Beams of Microwaves, for instance with frequencies of the order of 10 GHz, obtaining fair results even when having recourse to realistic apertures endowed with reasonable diameters. Our first proposal refers mainly to sets of suitable annular slits, having in mind various possible applications, including remote sensing. Our second proposal --which constitutes one of the main aims of this paper-- refers to the alternative, rather simple, use of a Parabolic Reflector, illuminated by a spherical wave source located on the paraboloid axis but slightly displaced with respect to the Focus of the Paraboloid. Such a parabolic reflector yields "extended focus" (non-diffracting) beams. [OCIS codes: 999.9999; 070.7545; 050.1120; 280.0280; 050.1755; 070.0070; 200.0200. Keywords: Non-Diffracting Waves; Microwaves; Remote sensing; Annular Arrays; Bessel beams; Extended focus; Reflecting paraboloids; Parabolic reflectors; Parabolic antennas].

  15. Joint Angle and Delay Estimation (JADE) in Antenna Array CDMA Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The estimate of signals parameters is very important in wireless communications. In this paper, we combine subspace-based blind channel estimation algorithm with the extension of the JADE-WSF algorithm to jointly estimate the Angles-of-Arrival (AOAs) and delays of multipath signals arriving at an antenna array in Code Division Multiple Access (CDMA) systems. Our approach uses a collection of estimates of a consistent chip-sample of space-time vector channel. The channel estimates are assumed to have constant path AOA and delay over a finite number of symbols. Unlike the traditional MUltiple SIgnal Classification (MUSIC) and Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) algorithms for the estimation of signals parameters, the proposed method can work when the number of paths exceeds the number of antennas. The Cramer-Rao Bound (CRB) and simulations are provided.

  16. An Evaluation Method of Small-scale Array Beam of Phased Array Antenna%一种相控阵天线小面阵波束评估方法

    Institute of Scientific and Technical Information of China (English)

    王海; 韩国栋; 张领飞; 武伟

    2016-01-01

    The synthesis of large scale phased array antenna is a difficulty in phased array antenna field. An evaluation method of combining physical test with theoretical derivation is introduced to evaluate the radiation performance of large⁃scale array by analyzing the pattern characteristics of small⁃scale arrays.This paper selects the suitable small⁃scale array,analyzes the pattern specifications of array elements,and obtains the pattern characteristics of small⁃scale array by using simulation and test method. The radiation mode of large⁃scale array is analyzed by using theoretical derivation method to obtain hardily its radiation characteristics. The hardware require⁃ment and test solution for small⁃scale array test are proposed.The test verification is performed with prototype.%大规模相控阵天线的综合问题是相控阵天线领域的技术难点,引入了一种实物测试与理论推导相结合的评估方法,通过分析小型阵列的方向图特性以评估大型阵列辐射性能。选取合适的小面阵规模,对阵中单元的方向图指标进行分析,通过仿真和测试的方法得到小型阵列的方向图特性,并借此通过理论推导的方法对大型阵列的辐射模式进行分析,快速便捷地得出其辐射特性。提出了小面阵试验应具备的硬件条件及测试方法,通过实物样机进行了测试验证。

  17. Spatial Steering of Cyclotron-Resonance Maser Array Antenna by Magnetic Fields

    International Nuclear Information System (INIS)

    The novel concept of radiation lobe generation and steering by cyclotron-resonance maser (CRM) array is presented. In this scheme the gain and phase of each CRM-element in the array are tuned by magnetic fields which control the cyclotron synchronism condition and the pitch-ratio of each CRM-element. These operating parameters are controlled by the magnetic fields of the solenoid and the kicker, respectively. A numerical example of a CRM-array operating in a gyro-TWT mode is presented. The radiation pattern of a 10-element CRM phased array (15 kV, 1A each) is calculated. The radiation lobe steering by the magnetic field controls is demonstrated in this analysis. A 40 lobe steering range is shown for the 10-element CRM-array at 7.3 GHz. An experimental device is built in our laboratory to demonstrate the active CRM-array antenna concept. Preliminary experimental results of gain and phase-delay of a single CRM-element, as function of electron-beam parameters are presented. These results are compared to the numerical model

  18. Tower-Top Antenna Array Calibration Scheme for Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Justine McCormack

    2007-10-01

    Full Text Available Recently, there has been increased interest in moving the RF electronics in basestations from the bottom of the tower to the top, yielding improved power efficiencies and reductions in infrastructural costs. Tower-top systems have faced resistance in the past due to such issues as increased weight, size, and poor potential reliability. However, modern advances in reducing the size and complexity of RF subsystems have made the tower-top model more viable. Tower-top relocation, however, faces many significant engineering challenges. Two such challenges are the calibration of the tower-top array and ensuring adequate reliability. We present a tower-top smart antenna calibration scheme designed for high-reliability tower-top operation. Our calibration scheme is based upon an array of coupled reference elements which sense the array's output. We outline the theoretical limits of the accuracy of this calibration, using simple feedback-based calibration algorithms, and present their predicted performance based on initial prototyping of a precision coupler circuit for a 2×2 array. As the basis for future study a more sophisticated algorithm for array calibration is also presented whose performance improves with array size.

  19. A comparison of atmospheric effects on differential phase for a two-element antenna array and nearby site test interferometer

    Science.gov (United States)

    Morabito, David D.; D'Addario, Larry; Finley, Susan

    2016-02-01

    Phased arrays of reflector antennas can be used to obtain effective area and gain that are much larger than is practical with a single antenna. This technique is routinely used by NASA for receiving weak signals from deep space. Phase alignment of the signals can be disrupted by turbulence in the troposphere, which causes fluctuations in the differences of signal delays among the antennas. At the Deep Space Network stations, site test interferometers (STIs) are being used for long-term monitoring of these delay fluctuations using signals from geostationary satellites. In this paper, we compare the STI measurements with the phase variations seen by a nearby two-element array of 34 m diameter antennas tracking 8.4 GHz and 32 GHz signals from the Cassini spacecraft in orbit around Saturn. It is shown that the statistics of the STI delay fluctuations, after appropriate scaling for differences in antenna separation and elevation angle and conversion to phase at the spacecraft frequencies, provide reliable estimates of the phase fluctuations seen by the large antennas on the deep space signal. Techniques for adaptive compensation of the phase fluctuations are available when receiving a sufficiently strong signal, but compensation is often impractical or impossible when using the array for transmitting. These results help to validate the use of long-term STI data for assessing the feasibility of large transmitting arrays at various sites.

  20. Xatcobeo: Small Mechanisms for CubeSat Satellites - Antenna and Solar Array Deployment

    Science.gov (United States)

    EncinasPlaza, Jose Miguel; VilanVilan, Jose Antonio; AquadoAgelet, Fernando; BrandiaranMancheno, Javier; LopezEstevez, Miguel; MartinezFernandez, Cesar; SarmientoAres, Fany

    2010-01-01

    The Xatcobeo project, which includes the mechanisms dealt with here, is principally a university project to design and construct a CubeSat 1U-type satellite. This work describes the design and operational features of the system for antenna storage and deployment, and the design and simulations of the solar array deployment system. It explains the various problems faced and solutions adopted, with a view to providing valid data for any other applications that could find them useful, be they of a similar nature or not.

  1. Human Skin as Arrays of Helical Antennas in the Millimeter and Submillimeter Wave Range

    Science.gov (United States)

    Feldman, Yuri; Puzenko, Alexander; Ben Ishai, Paul; Caduff, Andreas; Agranat, Aharon J.

    2008-03-01

    Recent studies of the minute morphology of the skin by optical coherence tomography showed that the sweat ducts in human skin are helically shaped tubes, filled with a conductive aqueous solution. A computer simulation study of these structures in millimeter and submillimeter wave bands show that the human skin functions as an array of low-Q helical antennas. Experimental evidence is presented that the spectral response in the sub-Terahertz region is governed by the level of activity of the perspiration system. It is also correlated to physiological stress as manifested by the pulse rate and the systolic blood pressure.

  2. Millimeter-wave imaging with frequency scanning antenna and optical arrayed waveguide gratings

    Science.gov (United States)

    He, Yuntao; Yu, Guoxin; Fu, Xinyu; Jiang, Yuesong

    2012-12-01

    The principle of a novel passive millimeter-wave (MMW) imaging method using frequency scanning antenna (FSA) and arrayed waveguide grating (AWG) is analyzed theoretically. The imaging processes are divided to three stages and discussed respectively. Then the FSA with 33~ 43GHz frequency scanning range is designed carefully with a field of view of +/-25°for the MMW imaging system. An AWG of 1×24 is then simply designed with a channel spacing of 0.5GHz. The designing and simulating demonstrated the feasibility to build such an imaging system which is progressing.

  3. Development of uncooled antenna-coupled microbolometer arrays for explosive detection and identification

    Science.gov (United States)

    Simoens, F.; Arnaud, A.; Castelein, P.; Goudon, V.; Imperinetti, P.; Lalanne Dera, J.; Meilhan, J.; Ouvier Buffet, J. L.; Pocas, S.; Maillou, T.; Hairault, L.; Gellie, P.; Barbieri, S.; Sirtori, C.

    2010-10-01

    Uncooled antenna-coupled microbolometer focal plane arrays have been specifically tailored for optimum performance in the 1-5 Terahertz range. A prototyping batch of 160 × 120 pixel chips has been designed and then processed above 8" silicon substrates. An actively illuminated system has been experimentally tested where Quantum Cascade Lasers (QCLs) are associated with the room-temperature operating 2D sensor. Whereas explosives samples were introduced in the THz beam optical path, the profile of the modified beam has been sensed by a unique pixel translated via an X-Y stage. These represent the first demonstration essays of explosive identification using our system.

  4. Microwave monolithic integrated circuit development for future spaceborne phased array antennas

    Science.gov (United States)

    Anzic, G.; Kascak, T. J.; Downey, A. N.; Liu, D. C.; Connolly, D. J.

    1984-01-01

    The development of fully monolithic gallium arsenide (GaAs) receive and transmit modules suitable for phased array antenna applications in the 30/20 gigahertz bands is presented. Specifications and various design approaches to achieve the design goals are described. Initial design and performance of submodules and associated active and passive components are presented. A tradeoff study summary is presented, highlighting the advantages of a distributed amplifier approach compared to the conventional single power source designs. Previously announced in STAR as N84-13399

  5. A COMBINED FULL-WAVE BCG-FFT METHOD FOR RADIATION OF MICROSTRIP ANTENNA ARRAYS

    Institute of Scientific and Technical Information of China (English)

    Zhang Hou; Peng Hongli; Liu Qizhong; Yin Yingzeng; Gong Shuxi

    2001-01-01

    A method of combining BiConjugate Gradient(BCG) with Fast Fourier Transform(FFT) to analyze the radiation of microstrip antenna arrays is presented, where the spatially discrete BCG-FFT for analyzing microstrip structure is used and the del operators on Green's functions are transferred from the singular kernel to the expansion and testing functions. The resultant equations are solved by using BCG method in which the matrix-vector product is evaluated efficiently with FFT. The calculated patterns are in good agreement with the measured data.

  6. Spatial-frequency-phase-time modulation of radio pulses in transmitting phased-array antennas

    OpenAIRE

    Gomozov, V. I.

    1995-01-01

    The work in this area was started by V.I. Gomozov and V.I. Zamyatin in 1978. Similar papers of foreign authors were published for the first time in 1988-1991. It is shown that in comparison with traditional spatial-phase modulation the proposed reciprocally matched spatial-frequency-phase-time modulation of radio pulses in the channels of transmitting Phased Array Antennas (PAA) has the following principal merits: duration of microwave radiation Focused Radio Pulse (FRP) is determined by the ...

  7. Optimal Design of Uniform Rectangular Antenna Arrays for Strong Line-of-Sight MIMO Channels

    Directory of Open Access Journals (Sweden)

    Frode Bøhagen

    2007-08-01

    Full Text Available We investigate the optimal design of uniform rectangular arrays (URAs employed in multiple-input multiple-output communications, where a strong line-of-sight (LOS component is present. A general geometrical model is introduced to model the LOS component, which allows for any orientation of the transmit and receive arrays, and incorporates the uniform linear array as a special case of the URA. A spherical wave propagation model is used. Based on this model, we derive the optimal array design equations with respect to mutual information, resulting in orthogonal LOS subchannels. The equations reveal that it is the distance between the antennas projected onto the plane perpendicular to the transmission direction that is of importance with respect to design. Further, we investigate the influence of nonoptimal design, and derive analytical expressions for the singular values of the LOS matrix as a function of the quality of the array design. To evaluate a more realistic channel, the LOS channel matrix is employed in a Ricean channel model. Performance results show that even with some deviation from the optimal design, we get better performance than in the case of uncorrelated Rayleigh subchannels.

  8. Optimal Design of Uniform Rectangular Antenna Arrays for Strong Line-of-Sight MIMO Channels

    Directory of Open Access Journals (Sweden)

    Orten Pål

    2007-01-01

    Full Text Available We investigate the optimal design of uniform rectangular arrays (URAs employed in multiple-input multiple-output communications, where a strong line-of-sight (LOS component is present. A general geometrical model is introduced to model the LOS component, which allows for any orientation of the transmit and receive arrays, and incorporates the uniform linear array as a special case of the URA. A spherical wave propagation model is used. Based on this model, we derive the optimal array design equations with respect to mutual information, resulting in orthogonal LOS subchannels. The equations reveal that it is the distance between the antennas projected onto the plane perpendicular to the transmission direction that is of importance with respect to design. Further, we investigate the influence of nonoptimal design, and derive analytical expressions for the singular values of the LOS matrix as a function of the quality of the array design. To evaluate a more realistic channel, the LOS channel matrix is employed in a Ricean channel model. Performance results show that even with some deviation from the optimal design, we get better performance than in the case of uncorrelated Rayleigh subchannels.

  9. FAILURE CORRECTION OF LINEAR ARRAY ANTENNA WITH MULTIPLE NULL PLACEMENT USING CUCKOO SEARCH ALGORITHM

    Directory of Open Access Journals (Sweden)

    R. Muralidaran

    2014-03-01

    Full Text Available The influence of evolutionary algorithms enhanced its scope of getting its existence in almost every complex optimization problems. In this paper, cuckoo search algorithm, an algorithm based on the brood parasite behavior along with Levy weights has been proposed for the radiation pattern correction of a linear array of isotropic antennas with uniform spacing when failed with more than one antenna element. Even though deterioration produced by the failure of antenna elements results in various undesirable effects, consideration in this paper is given to the correction of side lobe level and null placement at two places. Various articles in the past have already shown that the idea to correct the radiation pattern is to alter the amplitude weights of the remaining unfailed elements, instead of replacing the faulty elements. This approach is made use of modifying the current excitations of unfailed elements using cuckoo search algorithm such that the resulting radiation pattern is similar to the unfailed original pattern in terms of side lobe level and null placement at two places. Examples shown in this paper demonstrate the effectiveness of this algorithm in achieving the desired objectives.

  10. RF MEMS Phase Shifters and their Application in Phase Array Antennas

    Science.gov (United States)

    Scardelletti, Maximilian; Ponchak, George E.; Zaman, Afroz J.; Lee, Richard Q.

    2005-01-01

    Electronically scanned arrays are required for space based radars that are capable of tracking multiple robots, rovers, or other assets simultaneously and for beam-hopping communication systems between the various assets. ^Traditionally, these phased array antennas used GaAs Monolithic Microwave Integrated Circuit (MMIC) phase shifters, power amplifiers, and low noise amplifiers to amplify and steer the beam, but the development of RF MEMS switches over the past ten years has enabled system designers to consider replacing the GaAs MMIC phase shifters with RF Micro-Electro Mechanical System (MEMS) phase shifters. In this paper, the implication of replacing the relatively high loss GaAs MMICs with low loss MEMS phase shifters is investigated.

  11. FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

    Directory of Open Access Journals (Sweden)

    James Millar

    2006-10-01

    Full Text Available Field-programmable gate arrays (FPGAs are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs, through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs. In our study, we employ an Altera Stratix FPGA development board, along with the DSP Builder software tool which acts as a high-level interface to the powerful Quartus II environment. We compare single- and multibranch FPGA-based receiver designs in terms of error rate performance and power consumption. We exploit FPGA operational flexibility and algorithm parallelism to design eigenmode-monitoring receivers that can adapt to variations in wireless channel statistics, for high-performing, inexpensive, smart antenna array embedded systems.

  12. Terahertz Coded Aperture Mask using a Vanadium Dioxide Bowtie Antenna Array

    CERN Document Server

    Nadri, Souheil; Kittiwatanakul, Lin; Arsenovic, Alex; Lu, Jiwei; Wolf, Stu; Weikle, Robert M

    2015-01-01

    Terahertz imaging systems have received substantial attention from the scientific community for their use in astronomy, spectroscopy, plasma diagnostics and security. One approach to designing such systems is to use focal plane arrays. Although the principle of these systems is straightforward, realizing practical architectures has proven deceptively difficult. A different approach to imaging consists of spatially encoding the incoming flux of electromagnetic energy prior to detection using a reconfigurable mask. This technique is referred to as coded aperture or Hadamard imaging. This paper details the design, fabrication and testing of a prototype coded aperture mask operating at WR 1.5 (500 to 750 GHz) that uses the switching properties of vanadium dioxide (VO2). The reconfigurable mask consists of bowtie antennas with vanadium dioxide VO2 elements at the feed points. From the symmetry, a unit cell of the array can be represented by an equivalent waveguide whose dimensions limit the maximum operating frequ...

  13. FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

    Directory of Open Access Journals (Sweden)

    Millar James

    2006-01-01

    Full Text Available Field-programmable gate arrays (FPGAs are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs, through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs. In our study, we employ an Altera Stratix FPGA development board, along with the DSP Builder software tool which acts as a high-level interface to the powerful Quartus II environment. We compare single- and multibranch FPGA-based receiver designs in terms of error rate performance and power consumption. We exploit FPGA operational flexibility and algorithm parallelism to design eigenmode-monitoring receivers that can adapt to variations in wireless channel statistics, for high-performing, inexpensive, smart antenna array embedded systems.

  14. Low-Cost Planar MM-Wave Phased Array Antenna for Use in Mobile Satellite (MSAT) Platforms

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    In this paper, a compact 8×8 phased array antenna for mobile satellite (MSAT) devices is designed and investigated. 64-elements of 22 GHz patch antennas with coaxial-probe feeds have been used for the proposed planar design. The antenna is designed on a low-cost FR4 substrate with thickness......, dielectric constant, and loss tangent of 0.8 mm, 4.3, and 0.025, respectively. The antenna exhibits good performance in terms of impedance- matching, gain and efficiency characteristics, even though it is designed using high loss substrate with compact dimension (Wsub×Lsub=55×55 mm2). The antenna has more...... than 23 dB realized gain and -0.8 dB radiation efficiency when its beam is tilted to 0o elevation. The center frequency of the designed array can be controlled by adjusting the values of the antenna parameters. Compared with the previous designs, the proposed planar phased array has the advantages of...

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

    Science.gov (United States)

    duToit, Cornelis

    2014-01-01

    A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA's EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35deg off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array. EcoSAR is an airborne interferometric P-band synthetic aperture radar (SAR) research application for studying two- and three-dimensional fine-scale measurements of terrestrial ecosystem structure and biomass, which will ultimately aid in the broader study of the carbon cycle and climate change. The two 2×8 element Pband antenna arrays required by the system will be separated by a baseline of about 25 m, allowing for interferometry measurements. The wide 100-to- 200-MHz bandwidth dual-polarized beams employed will allow the determination of the amount of biomass and even tree height on the ground. To reduce the size of the patches along the boresight dimension in order to fit them into the available space, two techniques were employed. One technique is to add slots along the edges of each patch where the main electric currents are expected to flow, and the other technique is to bend the central part of the patch away from the ground plane. The latter also facilitates higher mechanical rigidity. The high port isolation of more than 40 dB was achieved by employing a highly symmetrical feed mechanism for each

  16. Substrate-guided wave true-time delay network for phased array antenna steering

    Science.gov (United States)

    Fu, Zhenhai

    2000-11-01

    Military and civilian wireless communication systems require compact phased array antenna systems with high performance. Unlike narrow-bandwidth phase shifters or bulky and lossy metallic time delay lines, photonic true- time delay lines open the possibility of high-performance antenna systems, while at the same time meeting the stringent weight and size requirements. Substrate-guided wave true-time delay lines, which have many advantages over other proposed structures, are proposed herein. The system structures of one-dimensional and two-dimensional antenna arrays based on the proposed true-time delay modules, along with the corresponding signal distribution methods for both transmit and receive modes were proposed and discussed. To demonstrate the generation and detection of microwave- encoded optical signal sources for the optically controlled antenna array, up to 50 GHz microwave signals with greater than 20 dB signal-to-noise ratios were generated by the optical heterodyning of two lasers with slightly different wavelengths at 786 nm or 1550 nm, demodulated by an ultra-fast photodetector, and then measured by a spectrum analyzer. The diffraction efficiencies of volume holographic gratings recorded on DuPont photopolymer for S-wave, P- wave, and random wave under different wavelengths were investigated in detail. The shrinkage effect of the holographic grating was compensated for by a proposed method shown herein. A simple method was also used to equalize the fanout beams to within +/-5%. Based on the above fabrication techniques, up to 7-bit TTD modules working at 850 nm and 1550 nm, which have the most number of bits and the highest packing density ever reported, were fabricated and packaged. The delay steps of the fabricated delay modules were experimentally confirmed using an original setup based on a femto-second laser, a high-speed photodetector, and the equivalent time sampling technique. The bandwidth of the delay module is experimentally confirmed to

  17. Angular super-resolution with array antennas: Application to seeker-heads

    Science.gov (United States)

    Nickel, U.

    1986-07-01

    Monopulse seeker-heads can give large errors due to closely spaced targets or even completely wrong directions in the case of cross-eye deception. The effective countermeasure against these errors is resolution enhancement. Super-resolution methods offer the possibility to resolve targets closer than the antenna beamwidth. Such methods are favorable for seeker-head applications, because the target separation as well as the signal-to-noise ratio increases as the missile approaches the target. All effective super-resolution methods require an antenna array with access to the single element outputs. Thus mechanical scanning is replaced by electronic scanning. Depending on the type of missile, sometimes antenna pattern restrictions have to be tolerated. Among all super-resolution methods the parametric target model fitting (PTMF) method seems to be most appropriate for this application. This method tries to fit a completely parameterized target model directly to the measured data. It can be rather easily computed, and it is the only method which can resolve completely correlated targets, which arise in the case of multipath and cross-eye deception. For seeker-heads with few antenna elements an implementation with digital signal processor chips is most suited. Computer simulations and experiments with measured data using the DESAS test equipment show that two targets separated at 0.3 beamwidth can be resolved in azimuth and elevation and that the switch from conventional monopulse to two-target estimation (super-resolution), which is crucial for the approaching missile, can be done by a reliable automatic test procedure.

  18. Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

    KAUST Repository

    Sirenko, Kostyantyn

    2011-01-01

    The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse\\'s efficient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.

  19. A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

    Directory of Open Access Journals (Sweden)

    Ivan Aldaya

    2015-01-01

    Full Text Available Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

  20. 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

  1. Numerical optimization of coaxial-to-microstrip transition to feed a printed quasi-Yagi element of phased antenna arrays

    Directory of Open Access Journals (Sweden)

    O. E. Vydalko

    2013-12-01

    Full Text Available Abstract. Paper presents numerical investigation of the coaxial-to-printed microstrip transition. Results were obtained by finite-difference time domain method. Rationale of the coaxial-to-microstrip transition type. Different types of coaxial-to-microstrip transitions were considered. Due to larger area of contact and a particular form of the connector a coaxial-to-microstrip transition with metal connector was chosen for next investigation. Design and radiation characteristics of a printed quasi-Yagi antenna. Matching characteristics and radiation pattern of the quasi-Yagi antenna was calculated. Optimized feeding system of the printed quasi-Yagi antenna through coaxial-to-microstrip transition. Radiation characteristics of the printed quasi-Yagi antenna fed by coaxial-to-microstrip transition were calculated. The investigation of changes in the geometry of the coaxial-to-microstrip transition on matching characteristics of the printed antenna. The impact of changes in the geometry of transition on antenna characteristics was investigated. Conclusions. To provide high performance electrical connection from coaxial cable to microstrip line the wide band coaxial-to-microstrip transition provided low level of loss and high mechanical strength has been designed. Such transition can be used in large phased antenna arrays built of various microstrip antennas.

  2. Impact ionization in high resistivity silicon induced by an intense terahertz field enhanced by an antenna array

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Zalkovskij, Maksim;

    2015-01-01

    antenna array. The carrier multiplication is probed by the frequency shift of the resonance of the antenna array due to the change of the local refractive index of the substrate. Experimental results and simulations show that the carrier density in silicon increases by over seven orders of magnitude in......We report on the observation of ultrafast impact ionization and carrier generation in high resistivity silicon induced by intense subpicosecond terahertz transients. Local terahertz peak electric fields of several MV cm−1 are obtained by field enhancement in the near field of a resonant metallic...

  3. 24-GHz LTCC Fractal Antenna Array SoP With Integrated Fresnel Lens

    KAUST Repository

    Ghaffar, Farhan Abdul

    2012-09-30

    A novel 24-GHz mixed low-temperature co-fired ceramic (LTCC) tape based system-on-package (SoP) is presented, which incorporates a fractal antenna array with an integrated grooved Fresnel lens. The four-element fractal array employs a relatively low dielectric constant substrate (CT707, εr = 6.4), whereas the lens has been realized on a high-dielectric-constant superstrate (CT765, εr = 68.7 ). The two (substrate and superstrate) are integrated through four corner posts to realize the required air gap (focal distance). The fractal array alone provides a measured gain of 8.9 dBi. Simulations predict that integration of this array with the lens increases the gain by 6 dB. Measurements reveal that the design is susceptible to LTCC fabrication tolerances. In addition to high gain, the SoP provides a bandwidth of 8%. The high performance and compact size (24 × 24 × 4.8 mm3 ) of the design makes it highly suitable for emerging wireless applications such as automotive radar front end.

  4. Computationally Efficient Blind Code Synchronization for Asynchronous DS-CDMA Systems with Adaptive Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Chia-Chang Hu

    2005-04-01

    Full Text Available A novel space-time adaptive near-far robust code-synchronization array detector for asynchronous DS-CDMA systems is developed in this paper. There are the same basic requirements that are needed by the conventional matched filter of an asynchronous DS-CDMA system. For the real-time applicability, a computationally efficient architecture of the proposed detector is developed that is based on the concept of the multistage Wiener filter (MWF of Goldstein and Reed. This multistage technique results in a self-synchronizing detection criterion that requires no inversion or eigendecomposition of a covariance matrix. As a consequence, this detector achieves a complexity that is only a linear function of the size of antenna array (J, the rank of the MWF (M, the system processing gain (N, and the number of samples in a chip interval (S, that is, 𝒪(JMNS. The complexity of the equivalent detector based on the minimum mean-squared error (MMSE or the subspace-based eigenstructure analysis is a function of 𝒪((JNS3. Moreover, this multistage scheme provides a rapid adaptive convergence under limited observation-data support. Simulations are conducted to evaluate the performance and convergence behavior of the proposed detector with the size of the J-element antenna array, the amount of the L-sample support, and the rank of the M-stage MWF. The performance advantage of the proposed detector over other DS-CDMA detectors is investigated as well.

  5. Theoretical study of 2 × 2 element planar array of equilateral triangular patch microstrip antenna in plasma medium

    Indian Academy of Sciences (India)

    K K Verma; K R Soni

    2005-01-01

    The radiation properties of 2 × 2 element planar array of equilateral triangular patch microstrip antenna in plasma medium are studied. The array factor and far-zone EM-mode and P-mode radiation fields of the array geometry are derived using vector wave function techniques and pattern multiplication approaches. The total field patterns and various characteristics of pattern such as half power beam width (HPBW), first null beam width (FNBW) and direction of maximum radiation are computed for two different values of progressive phase excitation difference between the elements. The results of this array geometry are obtained both in plasma medium and in free space and compared with those of single element equilateral triangular patch microstrip antenna.

  6. Effects of Antenna Beam Chromaticity on Redshifted 21~cm Power Spectrum and Implications for Hydrogen Epoch of Reionization Array

    CERN Document Server

    Thyagarajan, Nithyanandan; DeBoer, David; Bowman, Judd; Ewall-Wice, Aaron; Neben, Abraham; Patra, Nipanjana

    2016-01-01

    Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments from detecting redshifted 21~cm signals from the Epoch of Reionization (EoR). Upcoming experiments are faced with a challenge to deliver more collecting area per antenna element without degrading the data with systematics. This paper and its companions show that dishes are viable for achieving this balance using the Hydrogen Epoch of Reionization Array (HERA) as an example. Here, we specifically identify spectral systematics associated with the antenna power pattern as a significant detriment to all EoR experiments which causes the already bright foreground power to leak well beyond ideal limits and contaminate the otherwise clean EoR signal modes. A primary source of this chromaticity is reflections in the antenna-feed assembly and between structures in neighboring antennas. Using precise foreground simulations taking wide-field effects into account, we provide a framework to set cosmologica...

  7. Integrated antenna synthesis of the objects monitoring systems in the microwave band

    OpenAIRE

    Prudyus, I. N.; Zubkov, A. M.; Zakharia, Y. A.; Mymrikov, D. O.

    2009-01-01

    The article presents the principle of the integrated antenna synthesis of the objects monitoring systems in the microwave band. The main attention is paid to the selection of allocation and geometrical sizes of feed horns for providing identical beamwidth in mutually perpendicular planes.

  8. Demonstration of a micromachined planar distribution network in gap waveguide technology for a linear slot array antenna at 100 GHz

    Science.gov (United States)

    Rahiminejad, S.; Zaman, A. U.; Haasl, S.; Kildal, P.-S.; Enoksson, P.

    2016-07-01

    The need for high frequency antennas is rapidly increasing with the development of new wireless rate communication technology. Planar antennas have an attractive form factor, but they require a distribution network. Microstrip technology is most commonly used at low frequency but suffers from large dielectric and ohmic losses at higher frequencies and particularly above 100 GHz. Substrate-integrated waveguides also suffer from dielectric losses. In addition, standard rectangular waveguide interfaces are inconvenient due to the four flange screws that must be tightly fastened to the antenna to avoid leakage. The current paper presents a planar slot array antenna that does not suffer from any of these problems. The distribution network is realized by micromachining using low-loss gap waveguide technology, and it can be connected to a standard rectangular waveguide flange without using any screws or additional packaging. To realize the antenna at these frequencies, it was fabricated with micromachining, which offers the required high precision, and a low-cost fabrication method. The antenna was micromachined with DRIE in two parts, one silicon-on-insulator plate and one Si plate, which were both covered with Au to achieve conductivity. The input reflection coefficient was measured to be below 10 dB over a 15.5% bandwidth, and the antenna gain was measured to be 10.4 dBi, both of which are in agreement with simulations.

  9. Optical antenna arrays of carbon nanotubes and their fabrication on polyimide and transparent conducting oxides for direct device integration

    Science.gov (United States)

    Wang, Y.; Kempa, K.; Kimball, B.; Ren, Z. F.

    2005-11-01

    Vertically-aligned carbon nanotubes/nanofibers grown on various substrates by a direct-current plasma-enhanced chemical vapor deposition method have been shown experimentally to function as classical low-loss dipole antenna arrays at optical frequencies. Two fundamental antenna effects, e.g., the polarization effect and length matching effect, directly observed on large-scale CNT arrays in visible frequency range, hold them promising for industry-level fabrication of devices including linear/beam-splitting polarizers, solar energy converters, THz demodulators, etc., some of which will, however, require or prefer a flexible and/or transparent conducting substrate to be compatible for multi-level integration and low-cost manufacturing process. A low-energy dark discharge fabrication technique is therefore devised which successfully yields CNT antennas directly on polyimide films and transparent conducting oxides (ITO, ZnO) with the absence of a buffer layer.

  10. 毫米波微带天线阵列设计%Design of a millimeter wave microstrip antenna array

    Institute of Scientific and Technical Information of China (English)

    于慧娟

    2016-01-01

    A circular aperture millimeter wave series and parallel fed microstrip antenna array was proposed. The antenna was designed with rectangular microstrip patch which was fed by slot-coupled to increase the bandwidth. A series-fed microstrip antenna array was selected in order to use the antenna aperture area effectively and decrease the net complexity. At the same time, according to design of the circular aperture millimeter wave micro-strip antenna array, the part array was series and parallel fed to increase the bandwidth of the microstrip antenna. Results show that the bandwidth of the antenna is about 5%. The simulation result of the antenna’s gain is better than 30.6 dBi in working band. The beam width is about 4.0°×3.5° and the side lobe level is lower than –13 dB. Multi beam and phased array functions can be realized with the antenna array and the net.%设计了一个圆口径串并联混合馈电的毫米波微带天线阵列。该天线采用矩形微带工字型缝隙贴片耦合馈电的方法展宽带宽。为了有效利用天线口径面积,减小网络复杂度,选取串联微带天线阵列形式。同时为了展宽带宽,根据设计的圆形口径阵列,将部分子阵采用串并联混合馈电的形式,得到带宽为5%的毫米波微带天线阵列。仿真表明,该天线在工作频带内增益大于30.6 dBi,波束宽度为4.0°×3.5°,副瓣电平低于–13 dB。该天线阵面与网络配合,可以实现多波束或相控阵的功能。

  11. Nature-inspired Cuckoo Search Algorithm for Side Lobe Suppression in a Symmetric Linear Antenna Array

    Directory of Open Access Journals (Sweden)

    K. N. Abdul Rani

    2012-09-01

    Full Text Available In this paper, we proposed a newly modified cuckoo search (MCS algorithm integrated with the Roulette wheel selection operator and the inertia weight controlling the search ability towards synthesizing symmetric linear array geometry with minimum side lobe level (SLL and/or nulls control. The basic cuckoo search (CS algorithm is primarily based on the natural obligate brood parasitic behavior of some cuckoo species in combination with the Levy flight behavior of some birds and fruit flies. The CS metaheuristic approach is straightforward and capable of solving effectively general N-dimensional, linear and nonlinear optimization problems. The array geometry synthesis is first formulated as an optimization problem with the goal of SLL suppression and/or null prescribed placement in certain directions, and then solved by the newly MCS algorithm for the optimum element or isotropic radiator locations in the azimuth-plane or xy-plane. The study also focuses on the four internal parameters of MCS algorithm specifically on their implicit effects in the array synthesis. The optimal inter-element spacing solutions obtained by the MCS-optimizer are validated through comparisons with the standard CS-optimizer and the conventional array within the uniform and the Dolph-Chebyshev envelope patterns using MATLABTM. Finally, we also compared the fine-tuned MCS algorithm with two popular evolutionary algorithm (EA techniques include particle swarm optimization (PSO and genetic algorithms (GA.

  12. Radio Channel Sounding Using a Circular Horn Antenna Array in the Horizontal Plane in the 2.3 GHz Band

    DEFF Research Database (Denmark)

    Yamamoto, Atsushi; Sakata, Tsutomu; Ogawa, Koichi;

    2012-01-01

    This paper presents results from an outdoor radio propagation experiment at 2.35 GHz using a channel sounder and a spherical horn antenna array. The propagation test was performed in Aalborg city in Denmark. Comparing the ray-tracing results and the results obtained with the proposed method on the...

  13. Terahertz real-time imaging uncooled array based on antenna- and cavity-coupled bolometers.

    Science.gov (United States)

    Simoens, François; Meilhan, Jérôme

    2014-03-28

    The development of terahertz (THz) applications is slowed down by the availability of affordable, easy-to-use and highly sensitive detectors. CEA-Leti took up this challenge by tailoring the mature infrared (IR) bolometer technology for optimized THz sensing. The key feature of these detectors relies on the separation between electromagnetic absorption and the thermometer. For each pixel, specific structures of antennas and a resonant quarter-wavelength cavity couple efficiently the THz radiation on a broadband range, while a central silicon microbridge bolometer resistance is read out by a complementary metal oxide semiconductor circuit. 320×240 pixel arrays have been designed and manufactured: a better than 30 pW power direct detection threshold per pixel has been demonstrated in the 2-4 THz range. Such performance is expected on the whole THz range by proper tailoring of the antennas while keeping the technological stack largely unchanged. This paper gives an overview of the developed bolometer-based technology. First, it describes the technology and reports the latest performance characterizations. Then imaging demonstrations are presented, such as real-time reflectance imaging of a large surface of hidden objects and THz time-domain spectroscopy beam two-dimensional profiling. Finally, perspectives of camera integration for scientific and industrial applications are discussed. PMID:24567477

  14. A performance analysis of multi-hop ad hoc networks with adaptive antenna array systems

    CERN Document Server

    Ali, Olfa Ben Sik; Gagnon, Francois

    2010-01-01

    Based on a stochastic geometry framework, we establish an analysis of the multi-hop spatial reuse aloha protocol (MSR-Aloha) in ad hoc networks. We compare MSR-Aloha to a simple routing strategy, where a node selects the next relay of the treated packet as to be its nearest receiver with a forward progress toward the final destination (NFP). In addition, performance gains achieved by employing adaptive antenna array systems are quantified in this paper. We derive a tight upper bound on the spatial density of progress of MSR-Aloha. Our analytical results demonstrate that the spatial density of progress scales as the square root of the density of users, and the optimal contention density (that maximizes the spatial density of progress) is independent of the density of users. These two facts are consistent with the observations of Baccelli et al., established through an analytical lower bound and through simulations.

  15. An Improved Chaos Genetic Algorithm for T-Shaped MIMO Radar Antenna Array Optimization

    Directory of Open Access Journals (Sweden)

    Xin Fu

    2014-01-01

    Full Text Available In view of the fact that the traditional genetic algorithm easily falls into local optimum in the late iterations, an improved chaos genetic algorithm employed chaos theory and genetic algorithm is presented to optimize the low side-lobe for T-shaped MIMO radar antenna array. The novel two-dimension Cat chaotic map has been put forward to produce its initial population, improving the diversity of individuals. The improved Tent map is presented for groups of individuals of a generation with chaos disturbance. Improved chaotic genetic algorithm optimization model is established. The algorithm presented in this paper not only improved the search precision, but also avoids effectively the problem of local convergence and prematurity. For MIMO radar, the improved chaos genetic algorithm proposed in this paper obtains lower side-lobe level through optimizing the exciting current amplitude. Simulation results show that the algorithm is feasible and effective. Its performance is superior to the traditional genetic algorithm.

  16. Design of a tunable frequency selective surface absorber as a loaded receiving antenna array

    International Nuclear Information System (INIS)

    An effective approach to designing a tunable electromagnetic absorber is presented and experimentally verified; it is based on an idea that an existing frequency selective surface (FSS) absorber is regarded as a loaded receiving antenna array. The existing absorber is effectively simplified by withdrawing half of the loaded resistors; a more compact one is obtained when lumped capacitors are introduced. Building on this, a varactor-tunable absorber with a proper bias network is proposed. Numerical simulations of one tunable absorber with 1.6 mm in thickness show that a wide tuning range from 3.05 GHz to 1.96 GHz is achieved by changing the capacitance of the loaded varactor from 0.5 pF to 5.0 pF. An experiment is carried out using a rectangular waveguide measurement setup and excellent agreement between the simulated and measured results is demonstrated. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  17. Diamond dipole active antenna

    OpenAIRE

    Bubnov, I. N.; Falkovych, I. S.; Gridin, A. A.; Stanislavsky, A. A.; Reznik, A. P.

    2015-01-01

    Advantages of the diamond dipole antenna as an active antenna are presented. Such an antenna is like an inverted bow-tie antenna, but the former has some advantages over the ordinary bow-tie antenna. It is shown that the diamond dipole antenna may be an effective element of a new antenna array for low-frequency radio astronomy as well as a communication antenna.

  18. Combining the switched-beam and beam-steering capabilities in a 2-D phased array antenna system

    Science.gov (United States)

    Tsai, Yi-Che; Chen, Yin-Bing; Hwang, Ruey-Bing

    2016-01-01

    This paper presents the development, fabrication, and measurement of a novel beam-forming system consisting of 16 subarray antennas, each containing four aperture-coupled patch antennas, and the application of this system in smart wireless communication systems. The beam patterns of each of the subarray antennas can be switched toward one of nine zones over a half space by adjusting the specific phase delay angles among the four antenna elements. Furthermore, when all subarrays are pointed at the same zone, slightly continuous beam steering in around 1° increments can be achieved by dynamically altering the progressive phase delay angle among the subarrays. Phase angle calibration was implemented by coupling each transmitter output and down converter into the in-phase/quadrature baseband to calculate the correction factor to the weight. In addition, to validate the proposed concepts and the fabricated 2-D phased array antenna system, this study measured the far-field radiation patterns of the aperture-coupled patch array integrated with feeding networks and a phase-calibration system to carefully verify its spatially switched-beam and beam-steering characteristics at a center frequency of 2.4 GHz which can cover the industrial, scientific, and medical band and some long-term evolution applications. In addition, measured results were compared with calculated results, and agreement between them was observed.

  19. Triple Band Parasitic Array Antenna for C-X-Ku-Band Application Using Out-of-Phase Coupling Approach

    Directory of Open Access Journals (Sweden)

    Anubhuti Khare

    2014-01-01

    Full Text Available Triple band parasitic array antenna for C-X-Ku-band application is presented. The proposed antenna is designed using the concept of parasitic array and out-of-phase coupling approach. The objects of research are to optimize total inductance of geometry by using out-of-phase inductance approach. The out of phase inductance of geometry consists of using two U-patches novel director on the left side of geometry, appropriate dimension of ground plan, and gap coupling between parasitic and active patches. The dimension of the ground plan geometry is 0.5λ mil × 0.5154λ mil. The usable impedance bandwidth of design antenna is “5.8 GHz to 18 GHz” (102% impedance bandwidth and gain enhancement is up to 11.8 dBi. The proposed antenna can be used for X-Ku band and C-band applications. Both simulated and measured results are presented, which are in good agreement. The proposed antenna was fabricated with a thin copper layer printed on a thin lossy FR4 substrate for low-cost production.

  20. Compact optical true time delay beamformer for a 2D phased array antenna using tunable dispersive elements.

    Science.gov (United States)

    Ye, Xingwei; Zhang, Fangzheng; Pan, Shilong

    2016-09-01

    A hardware-compressive optical true time delay architecture for 2D beam steering in a planar phased array antenna is proposed using fiber-Bragg-grating-based tunable dispersive elements (TDEs). For an M×N array, the proposed system utilizes N TDEs and M wavelength-fixed optical carriers to control the time delays. Both azimuth and elevation beam steering are realized by programming the settings of the TDEs. An experiment is carried out to demonstrate the delay controlling in a 2×2 array, which is fed by a wideband pulsed signal. Radiation patterns calculated from the experimentally measured waveforms at the four antennas match well with the theoretical results. PMID:27607946

  1. Direction Finding Using Multiple Sum and Difference Patterns in 4D Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Quanjiang Zhu

    2014-01-01

    Full Text Available Traditional monopulse systems used for direction finding usually face the contradiction between high angle precision and wide angle-searching field, and a compromise has to be made. In this paper, the time modulation technique in four-dimensional (4D antenna array is introduced into the conventional phase-comparison monopulse to form a novel direction-finding system, in which both high angle resolution and wide field-of-view are realized. The full 4D array is divided into two subarrays and the differential evolution (DE algorithm is used to optimize the time sequence of each subarray to generate multibeams at the center frequency and low sidebands. Then the multibeams of the two subarrays are phase-compared with each other and multiple pairs of sum-difference beams are formed at different sidebands and point to different spatial angles. The proposed direction-finding system covers a large field-of-view of up to ±60° and simultaneously maintains the advantages of monopulse systems, such as high angle precision and low computation complexity. Theoretical analysis and experimental results validate the effectiveness of the proposed system.

  2. A multi-static ground-penetrating radar with an array of resistively loaded vee dipole antennas for landmine detection

    Science.gov (United States)

    Kim, Kangwook; Gurbuz, Ali C.; Scott, Waymond R., Jr.; McClellan, James H.

    2005-06-01

    A multi-static ground-penetrating radar (GPR) has been developed to investigate the potential of multi-static inversion algorithms. The GPR consists of a linear array of six resistively-loaded vee dipoles (RVDs), a network analyzer, and a microwave switch matrix all under computer control. The antennas in the array are spaced 12cm apart so the spacing between the transmitter and the receiver pairs in the measurements are from 12cm to 96cm in 12cm increments. The size of the array is suitable for the landmine problem and scaled measurements of the buried structure problem. The RVD is chosen as an array element because it is very "clean" in that it has very little self clutter and a very low radar cross section to lessen the reflections between the ground and the antenna. The shape and the loading profile of the antenna are designed to decrease the reflection at the drive point of the antenna while increasing the forward gain. The antenna and balun are made in a module, which is mechanically reliable without significant performance degradation. The multi-static GPR operation is demonstrated on targets buried in clean sand and targets buried under the ground covered by rocks. The responses of the targets are measured by each transmitter-receiver pair. A synthetic aperture, multi-static GPR imaging algorithm is extended from conventional monostatic back-projection techniques and used to process the data. Initial images obtained from the multi-static data are clearer than those obtained from bistatic data.

  3. 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

  4. Quadrature transmit array design using single-feed circularly polarized patch antenna for parallel transmission in MR imaging.

    Science.gov (United States)

    Pang, Yong; Yu, Baiying; Vigneron, Daniel B; Zhang, Xiaoliang

    2014-02-01

    Quadrature coils are often desired in MR applications because they can improve MR sensitivity and also reduce excitation power. In this work, we propose, for the first time, a quadrature array design strategy for parallel transmission at 298 MHz using single-feed circularly polarized (CP) patch antenna technique. Each array element is a nearly square ring microstrip antenna and is fed at a point on the diagonal of the antenna to generate quadrature magnetic fields. Compared with conventional quadrature coils, the single-feed structure is much simple and compact, making the quadrature coil array design practical. Numerical simulations demonstrate that the decoupling between elements is better than -35 dB for all the elements and the RF fields are homogeneous with deep penetration and quadrature behavior in the area of interest. Bloch equation simulation is also performed to simulate the excitation procedure by using an 8-element quadrature planar patch array to demonstrate its feasibility in parallel transmission at the ultrahigh field of 7 Tesla. PMID:24649430

  5. Ultra-Wideband Vivaldi Antenna Array for High Resolution Subsurface Imaging

    Science.gov (United States)

    Yedlin, M. J.; Cresp, A.; Pichot, C.; Aliferis, I.; Dauvignac, J.; Fortino, N.; Gaffet, S.

    2008-05-01

    Use of ultra-wideband electromagnetic waves to image the subsurface yields enhanced resolution, provided sources, antennas and recording equipment can be developed and calibrated over the complete bandwidth of interest. We present a demonstration of the latest microwave transmission and recording technology to obtain high-resolution images. Our transmitter and receiver electronics are embodied in the vector network analyzer (PNA series) from Agilent, an eight-port vector network analyzer that records amplitude and phase. The analyzer is connected through a microwave multiplexer and microwave switch to an 8 element, balanced, antipodal Vivaldi antenna array, which can transmit or receive data over a bandwidth from 1.3 to 20 GHz. The bandwidth of the integrated system is determined by the bandwidth of the microwave switch, from DC to 18GHz, which interfaces the multiplexer to the PNA. The capabilities of a microwave multiplexer are employed to collect multi-channel data, by using one channel for transmission and reception on all 8 channels. The demonstration of this integrated system will be focussed on scattering from a single conducting cylinder as well as two cylinders, a dielectric and conducting cylinder, spaced at different intervals. The increased bandwidth, over that obtained in conventional GPR recording will result in pulses that have little ringing, allowing the detection of deeper reflections and eliminating any post-processing distortions that arise from deconvolving the traditional oscillatory waveform. Although the demonstration will be presented in the GHz bandwidth, suitable for imaging over a length scale to 1m, this integrated system will scale to lower bandwidths and can operate from 100 MHz to 3 GHz, with a resultant penetration depth of 10 to 20 m depending on the subsurface properties. Given the electronic constraints of the switch and the PNA, this scaling is simply achieved by enlarging the Vivaldi antenna dimensions. The advantage of using

  6. Investigation of the SIW technology for low cost 60 GHz radio over fiber based array antenna units

    Science.gov (United States)

    Makris, D.; Tsiakas, P.; Voudouris, K.; Thakur, M. P.; Mikroulis, S.

    2015-01-01

    In this paper, a Substrate Integrated Waveguide (SIW) based photonic antenna suitable for RoF applications is presented. The millimeter-wave design is based on a diplexer, two Chebyshev bandpass filters, one for uplink (61,7GHz to 62,7 GHz) and one for downlink (59,3 GHz to 60,3 GHz) and one common 8x8 Slot array antenna, integrated on the same substrate. E/M simulations of a fully integrated planar RF Front End provide very good results, both in diplexer and filters and in antenna characteristics. Finally, a consideration regarding transition requirements for integration with a coplanar waveguide (CPW) photodiode is being presented.

  7. Beam-Steerable Microstrip-Fed Bow-Tie Antenna Array for Fifth Generation Cellular Communications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert Frølund

    2016-01-01

    bow-tie antennas have been used at the top-edge region of mobile phone PCB. The antenna elements fed by microstrip lines are designed to operate at 17 GHz. The simulated results give good performances in terms of different antenna parameters. In addition, an investigation on the distance between...

  8. Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics.

    Science.gov (United States)

    Hoang, Thang B; Huang, Jiani; Mikkelsen, Maiken H

    2016-01-01

    We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors. PMID:27285421

  9. Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

    Science.gov (United States)

    Hoang, Thang B.; Huang, Jiani; Mikkelsen, Maiken H.

    2016-01-01

    We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors. PMID:27285421

  10. Effects of the Number of Active Receiver Channels on the Sensitivity of a Reflector Antenna System with a Multi-Beam Wideband Phased Array Feed

    CERN Document Server

    Iupikov, O

    2016-01-01

    A method for accurate modeling of a reflector antenna system with a wideband phased array feed is presented and used to study the effects of the number of active antenna elements and associated receiving channels on the receiving sensitivity of the antenna system. Numerical results are shown for a practical design named APERTIF that is currently under developed at The Netherlands Institute for Radio Astronomy (ASTRON).

  11. Reliability-centered maintenance for ground-based large optical telescopes and radio antenna arrays

    Science.gov (United States)

    Marchiori, G.; Formentin, F.; Rampini, F.

    2014-07-01

    In the last years, EIE GROUP has been more and more involved in large optical telescopes and radio antennas array projects. In this frame, the paper describes a fundamental aspect of the Logistic Support Analysis (LSA) process, that is the application of the Reliability-Centered Maintenance (RCM) methodology for the generation of maintenance plans for ground-based large optical telescopes and radio antennas arrays. This helps maintenance engineers to make sure that the telescopes continue to work properly, doing what their users require them to do in their present operating conditions. The main objective of the RCM process is to establish the complete maintenance regime, with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems. At the same time, a correct application of the RCM allows to increase the cost effectiveness, telescope uptime and items availability, and to provide greater understanding of the level of risk that the organization is managing. At the same time, engineers shall make a great effort since the initial phase of the project to obtain a telescope requiring easy maintenance activities and simple replacement of the major assemblies, taking special care on the accesses design and items location, implementation and design of special lifting equipment and handling devices for the heavy items. This maintenance engineering framework is based on seven points, which lead to the main steps of the RCM program. The initial steps of the RCM process consist of: system selection and data collection (MTBF, MTTR, etc.), definition of system boundaries and operating context, telescope description with the use of functional block diagrams, and the running of a FMECA to address the dominant causes of equipment failure and to lay down the Critical Items List. In the second part of the process the RCM logic is applied, which helps to determine the appropriate maintenance tasks for each identified failure mode. Once

  12. Enchanced interference cancellation and telemetry reception in multipath environments with a single paraboic dish antenna using a focal plane array

    Science.gov (United States)

    Mukai, Ryan (Inventor); Vilnrotter, Victor A. (Inventor)

    2011-01-01

    An Advanced Focal Plane Array ("AFPA") for parabolic dish antennas that exploits spatial diversity to achieve better channel equalization performance in the presence of multipath (better than temporal equalization alone), and which is capable of receiving from two or more sources within a field-of-view in the presence of multipath. The AFPA uses a focal plane array of receiving elements plus a spatio-temporal filter that keeps information on the adaptive FIR filter weights, relative amplitudes and phases of the incoming signals, and which employs an Interference Cancelling Constant Modulus Algorithm (IC-CMA) that resolves multiple telemetry streams simultaneously from the respective aero-nautical platforms. This data is sent to an angle estimator to calculate the target's angular position, and then on to Kalman filters FOR smoothing and time series prediction. The resulting velocity and acceleration estimates from the time series data are sent to an antenna control unit (ACU) to be used for pointing control.

  13. Graphene-based fine-tunable optical delay line for optical beamforming in phased-array antennas.

    Science.gov (United States)

    Tatoli, Teresa; Conteduca, Donato; Dell'Olio, Francesco; Ciminelli, Caterina; Armenise, Mario N

    2016-06-01

    The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=920  ps) together with a compact footprint (4.15  mm2) and optical loss synthetic aperture radar has been designed. PMID:27411185

  14. A Wearable Microwave Antenna Array for Time-Domain Breast Tumor Screening.

    Science.gov (United States)

    Porter, Emily; Bahrami, Hadi; Santorelli, Adam; Gosselin, Benoit; Rusch, Leslie A; Popovic, Milica

    2016-06-01

    In this work, we present a clinical prototype with a wearable patient interface for microwave breast cancer detection. The long-term aim of the prototype is a breast health monitoring application. The system operates using multistatic time-domain pulsed radar, with 16 flexible antennas embedded into a bra. Unlike the previously reported, table-based prototype with a rigid cup-like holder, the wearable one requires no immersion medium and enables simple localization of breast surface. In comparison with the table-based prototype, the wearable one is also significantly more cost-effective and has a smaller footprint. To demonstrate the improved functionality of the wearable prototype, we here report the outcome of daily testing of the new, wearable prototype on a healthy volunteer over a 28-day period. The resulting data (both signals and reconstructed images) is compared to that obtained with our table-based prototype. We show that the use of the wearable prototype has improved the quality of collected volunteer data by every investigated measure. This work demonstrates the proof-of-concept for a wearable breast health monitoring array, which can be further optimized in the future for use with patients with various breast sizes and tissue densities. PMID:26780788

  15. Highly-Integrated, Reconfigurable, Large-Area, Flexible Radar Antenna Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reconfigurable antennas are attractive for remote sensing, surveillance and communications, since they enable changes in operating frequency and / or radiation...

  16. Development of Wideband, Dual Polarized L-Band Array Antenna for Digital Beam forming SAR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Using analytical methods to conceptualization L-band antenna structures that offer potentials of wideband operation. Perform extensive computer simulations on these...

  17. Designing Adaptive Linear Array Antenna to Achieve Pattern Steering Optimization by Phase-Amplitude Perturbations Using Genetic Algorithms

    Institute of Scientific and Technical Information of China (English)

    HSUChaohsing; CHENTsongyi; PanJengshyang

    2005-01-01

    In this paper, a phase-amplitude perturbation method of an adaptive array factor based on the genetic algorithm is proposed. The design for an optimal beam pattern of an adaptive antenna is able to not only suppress interference by placing nulls at the directions of the interfering sources but also provide a maximized main lobe in the direction of the desired signal, i.e., to maximizethe Signal interference ratio (SIR). In order to achieve this goal, a kind of new convergent skill called the two-way convergent method for genetic algorithms is proposed. The phase-amplitude perturbation method is applied to realize the optimal beam pattern of an adaptively linear array antenna. The Genetic algorithms are applied to find the optimal phase-amplitude weighting vector of adaptive array factor. An optimal beam pattern of linear array is derived by phase-amplitude perturbations using a genetic algorithm. Computer simulation result is given to demonstrate the effectiveness of the proposed method.

  18. The mathematical model of antenna and antenna-radome system

    OpenAIRE

    Knyazeva, L. V.; Artishev, A. I.

    2003-01-01

    Methods, algorithms and programs for calculation by computer of the characteristics of the antenna and the antenna-radome system (ARS) are developed. The type of antenna considered is the phased antenna array (PAA) or the cophase antenna with a mechanical beam control (an antenna array - AA). Radome shape is spherical, quasi-conic or flattened ellipsoid. Radome shell is multilayer ( N≥1), same-thickness, or special profile. Errors in the manufacture of the antenna are taken into account. Prog...

  19. Collaboration on Modeling of Ion Bernstein Wave Antenna Array and Coupling to Plasma on Tokamak Fusion Text Reactor. Final report

    International Nuclear Information System (INIS)

    This proposal was peer reviewed and funded as a Collaboration on ''Low Phase Speed Radio Frequency Current Drive Experiments at the Tokamak Fusion Test Reactor''. The original plans we had were to carry out the collaboration proposal by including a post doctoral scientist stationed at PPPL. In response to a 60+% funding cut, all expenses were radically pruned. The post doctoral position was eliminated, and the Principal Investigator (T. Intrator) carried out the brunt of the collaboration. Visits to TFTR enabled T. Intrator to set up access to the TFTR computing network, database, and get familiar with the new antennas that were being installed in TFTR during an up to air. One unfortunate result of the budget squeeze that TFTR felt for its last year of operation was that the experiments that we specifically got funded to perform were not granted run time on TFTR., On the other hand we carried out some modeling of the electric field structure around the four strap direct launch Ion Bernstein Wave (IBW) antenna that was operated on TFTR. This turned out to be a useful exercise and shed some light on the operational characteristics of the IBW antenna and its coupling to the plasma. Because of this turn of events, the project was renamed ''Modeling of Ion Bernstein Wave Antenna Array and Coupling to Plasma on Tokamak Fusion Test Reactor''

  20. Effects of Antenna Beam Chromaticity on Redshifted 21 cm Power Spectrum and Implications for Hydrogen Epoch of Reionization Array

    Science.gov (United States)

    Thyagarajan, Nithyanandan; Parsons, Aaron R.; DeBoer, David R.; Bowman, Judd D.; Ewall-Wice, Aaron M.; Neben, Abraham R.; Patra, Nipanjana

    2016-07-01

    Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments from detecting redshifted 21 cm signals from the Epoch of Reionization (EoR). Upcoming experiments are faced with a challenge to deliver more collecting area per antenna element without degrading the data with systematics. This paper and its companions show that dishes are viable for achieving this balance using the Hydrogen Epoch of Reionization Array (HERA) as an example. Here, we specifically identify spectral systematics associated with the antenna power pattern as a significant detriment to all EoR experiments which causes the already bright foreground power to leak well beyond ideal limits and contaminate the otherwise clean EoR signal modes. A primary source of this chromaticity is reflections in the antenna-feed assembly and between structures in neighboring antennas. Using precise foreground simulations taking wide-field effects into account, we provide a generic framework to set cosmologically motivated design specifications on these reflections to prevent further EoR signal degradation. We show that HERA will not be impeded by such spectral systematics and demonstrate that even in a conservative scenario that does not perform removal of foregrounds, HERA will detect the EoR signal in line-of-sight k-modes, {k}\\parallel ≳ 0.2 h Mpc‑1, with high significance. Under these conditions, all baselines in a 19-element HERA layout are capable of detecting EoR over a substantial observing window on the sky.

  1. Design of an electric power system with incorporation of a phased array antenna for OLFAR

    NARCIS (Netherlands)

    Klein, J.M.; Budianu, A.; Bentum, M.J.; Engelen, S.; Verhoeven, C.J.M.

    2013-01-01

    The Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR) project is investigating the feasibility of an orbiting low frequency radio telescope. The radio telescope is formed using a swarm of nano-satellites equipped with astronomical antennas, conceivably orbiting the Moon or the second Lagra

  2. Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging

    Science.gov (United States)

    Simoens, F.; Meilhan, J.; Gidon, S.; Lasfargues, G.; Lalanne Dera, J.; Ouvrier-Buffet, J. L.; Pocas, S.; Rabaud, W.; Guellec, F.; Dupont, B.; Martin, S.; Simon, A. C.

    2013-09-01

    CEA-Leti has developed a monolithic large focal plane array bolometric technology optimized for 2D real-time imaging in the terahertz range. Each pixel consists in a silicon microbolometer coupled to specific antennas and a resonant quarter-wavelength cavity. First prototypes of imaging arrays have been designed and manufactured for optimized sensing in the 1-3.5THz range where THz quantum cascade lasers are delivering high optical power. NEP in the order of 1 pW/sqrt(Hz) has been assessed at 2.5 THz. This paper reports the steps of this development, starting from the pixel level, to an array associated monolithically to its CMOS ROIC and finally a stand-alone camera. For each step, modeling, technological prototyping and experimental characterizations are presented.

  3. Analysis of a Combined Antenna Arrays and Reverse-Link Synchronous DS-CDMA System over Multipath Rician Fading Channels

    Directory of Open Access Journals (Sweden)

    Kim Yong-Seok

    2005-01-01

    Full Text Available We present the BER analysis of antenna array (AA receiver in reverse-link asynchronous multipath Rician channels and analyze the performance of an improved AA system which applies a reverse-link synchronous transmission technique (RLSTT in order to effectively make a better estimation of covariance matrices at a beamformer-RAKE receiver. In this work, we provide a comprehensive analysis of user capacity which reflects several important factors such as the ratio of the specular component power to the Rayleigh fading power, the shape of multipath intensity profile, and the number of antennas. Theoretical analysis demonstrates that for the case of a strong specular path's power or for a high decay factor, the employment of RLSTT along with AA has the potential of improving the achievable capacity by an order of magnitude.

  4. The Hydrogen Epoch of Reionization Array (HERA). Improvement of the antenna response with a matching network and scientific impacts

    CERN Document Server

    Fagnoni, Nicolas

    2016-01-01

    The Hydrogen Epoch of Reionization Array (HERA) is a new powerful radio-telescope, dedicated to the study of the early universe. Its main goal is to characterise the period of the universe where the first galaxies and stars started to form, by studying the evolution of the 21-cm emission signal from neutral hydrogen, during the Epoch of Reionization. In this article, we present an electromagnetic and electrical co-simulation of the antenna performed with CST. We focus our analysis on the characterisation of the chromatic effects caused by the antenna, in particular multiple reflections of the received signal between the feed and the dish. These reflections can have an important impact on the scientific results, and it is crucial to keep them as low as possible. Therefore, we are currently developing a matching circuit which aims to improve the impedance matching between the feed and the front end.

  5. Envelope correlation in (N, N) MIMO antenna array from scattering parameters

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2006-01-01

    the envelope correlation coefficient. This approach has the advantage that it does not require knowledge of the antenna radiation pattern. Numerical data that include conductor and permittivity loss are shown to validate the approach. Using the scattering parameters for calculating the envelope......A simple closed-form equation to calculate the envelope correlation between any two receiver or transmitter antennas in a multi-input multi-output (MIMO) system of an arbitrary number of elements is derived. The equation uses the scattering parameters obtained at the antenna feed point to calculate...... correlation is less laborious and relatively cheaper, as compared to the radiation pattern approach....

  6. A Low Cost, Electronically Scanned Array (ESA) Antenna Technology for Aviation Hazard Detection and Avoidance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase II project includes the design, fabrication, and testing of a fully-functional 320 element X-band antenna which will serve dual-roles as both the...

  7. High-Performance Wireless via the Merger of CI Chip-Shaped DS-CDMA and Oscillating-Beam Smart Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Seyed Alireza Zekavat

    2004-08-01

    Full Text Available We introduce a novel merger of direct sequence code division multiple access (DS-CDMA and smart antenna arrays. With regard to the DS-CDMA scheme, we employ carrier interferometry DS-CDMA (CI/DS-CDMA, a novel implementation of DS-CDMA where chips are decomposable into N narrowband frequency components. With regard to the antenna array, we deploy the oscillating-beam smart array. Here, applying proper time-varying phases to the array elements, we create small movement (oscillation in the antenna array's pattern, while steering the antenna pattern main lobe to the position of the intended user. The oscillating antenna pattern creates a time-varying channel with a controllable coherence time. This, in turn, provides transmit diversity in the form of a time diversity gain at the mobile receiver side. At the receiver, three stages of combining are available: combining time components of the received signal within symbol duration TS (each experiencing a different fade to enhance performance via time diversity; combining frequency components which make up the CI/DS-CDMA chip to enhance the performance via frequency diversity; and combining across chips to eliminate the interfering users on the system. Merging CI/DS-CDMA with the oscillating-beam smart antenna at the base station, we achieve very high capacity via the merger of SDMA (available through directionality of the antenna array and code division multiple access (inherent in CI/DS-CDMA, and very high performance via the construction of receivers that exploit both transmit diversity and frequency diversity. We present the performance gains of the proposed merger.

  8. Recent advances in electromagnetic synthesis and analysis of dual-shaped reflector antennas

    Science.gov (United States)

    Galindo-Israel, V.; Rahmat-Samii, Y.; Imbriale, W.; Mittra, R.

    1982-01-01

    Dual-shaped reflectors have been used for many years. Thus, these reflectors have been used as high gain antennas on Voyagers 1 and 2. The objectives of the geometrical optics (GO) dual shaped synthesis are considered. Concerning the synthesis of dual shaped reflectors, it has been shown for circular symmetric reflectors that an exact GO solution can be found to the problem of transforming, by two reflections, any feed pattern into any aperture distribution. This problem involves solving two simultaneous nonlinear ordinary differential equations. The same approach for offset geometry leads to two simultaneous nonlinear partial differential equations. It is shown that these equations could also be integrated numerically, except that in general these equations are not total and therefore, in general, they do not have a 'smooth' solution. It is further shown that the offset partial differentials often very nearly form a total differential in many cases of practical importance.

  9. A MIMO Reversed Antenna Array Design for gsm1800/td-scdma/lte/wi-max/wiLan/wifi

    Directory of Open Access Journals (Sweden)

    Fang Xu

    2015-01-01

    Full Text Available A triband MIMO antenna used for gsm1800/td-scdma/lte/wi-max/wiLan/wifi has been proposed in this paper. The design with the size of 32 m ∗ 73.6 mm is fabricated on FR4 substrate (thickness is 1.6 mm. This antenna consists of two reversed monopole meandered radiators and defected ground structure which work together to achieve impedance match and enhance isolation for all operating bands. According to the subsequent measured results, the working frequency domains are at gsm1800 (1.71 GHz–1.88 GHz, td-scdma (1.88 GHz–2.025 GHz, lte (2.1–2.35, 2.48–2.51, wi-max (3.5 GHz, 5.5 GHz, wiLan (5.725 GHz–5.8 GHz, and wifi (5.8 GHz–5.88 GHz approximately. Besides, the measured radiation patterns (gain total are also well at these working frequency domains and the omnidirectional performance has been achieved for the reversed MIMO antenna array. Furthermore, the realized isolation is more than 15 dB, 24.2 dB, and 22 dB at the first, the second, and the third working frequency band, respectively.

  10. High throughput optical lithography by scanning a massive array of bowtie aperture antennas at near-field

    Science.gov (United States)

    Wen, X.; Datta, A.; Traverso, L. M.; Pan, L.; Xu, X.; Moon, E. E.

    2015-11-01

    Optical lithography, the enabling process for defining features, has been widely used in semiconductor industry and many other nanotechnology applications. Advances of nanotechnology require developments of high-throughput optical lithography capabilities to overcome the optical diffraction limit and meet the ever-decreasing device dimensions. We report our recent experimental advancements to scale up diffraction unlimited optical lithography in a massive scale using the near field nanolithography capabilities of bowtie apertures. A record number of near-field optical elements, an array of 1,024 bowtie antenna apertures, are simultaneously employed to generate a large number of patterns by carefully controlling their working distances over the entire array using an optical gap metrology system. Our experimental results reiterated the ability of using massively-parallel near-field devices to achieve high-throughput optical nanolithography, which can be promising for many important nanotechnology applications such as computation, data storage, communication, and energy.

  11. Analysis of the phase control of the ITER ICRH antenna array. Influence on the load resilience and radiated power spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Messiaen, A., E-mail: a.messiaen@fz-juelich.de; Ongena, J.; Vervier, M. [Laboratory for Plasma Physics, ERM-KMS, TEC partner, Cycle, B1000-Brussels (Belgium); Swain, D. [US ITER Team, ORNL (United States)

    2015-12-10

    The paper analyses how the phasing of the ITER ICRH 24 strap array evolves from the power sources up to the strap currents of the antenna. The study of the phasing control and coherence through the feeding circuits with prematching and automatic matching and decoupling network is made by modeling starting from the TOPICA matrix of the antenna array for a low coupling plasma profile and for current drive phasing (worst case for mutual coupling effects). The main results of the analysis are: (i) the strap current amplitude is well controlled by the antinode V{sub max} amplitude of the feeding lines, (ii) the best toroidal phasing control is done by the adjustment of the mean phase of V{sub max} of each poloidal straps column, (iii) with well adjusted system the largest strap current phasing error is ±20°, (iv) the effect on load resilience remains well below the maximum affordable VSWR of the generators, (v) the effect on the radiated power spectrum versus k{sub //} computed by means of the coupling code ANTITER II remains small for the considered cases.

  12. Performance of direct sequence CDMA for uniform linear and uniform circular antenna arrays in a cellular radio environment

    International Nuclear Information System (INIS)

    The BER (Bit Error Rate) performance of uniform linear and uniform circular array is analyzed in a single-cell cellular radio environment. We also compare the performance of direct sequence CDMA (Code Division Multiple Access) systems in multi user cellular environment with the published results for spatially correlated Rayleigh fading channel. The analytical BER is derived as function of antenna correlation for both types of antennas. The aim of this paper is to examine in detail the effect of AOA (Angle of Arrival) distributions, angle spread on the system performance and provide new results. The analysis is also applied to non-CDMA systems. Results show that the central AOA can have significant impact on BER performance for linear and circular arrays. It will be shown that the proposed expression in literature does not fully utilize the spatial diversity advantage. The main focus is on small to medium angle spread, which is common in cellular environment. Truncated Gaussian AOA distributions are assumed to model spatial correlation. (author)

  13. Phased Array GNSS Antenna for the FORMOSAT-7/COSMIC-2 Radio Occultation Mission

    Science.gov (United States)

    Turbiner, Dmitry; Young, Larry E.; Meehan, Tom K.

    2012-01-01

    Future GNSS remote sensing instruments such as the TriG receiver require more capable antennas than those flown on missions such as COSMIC. To maximize the number of ionospheric and atmospheric profiles, the TriG receiver will be capable of tracking legacy and new GPS signals such as L5, L2C and L1C; GLONASS CDMA and Galileo E1 and E5a. There has been an in-house effort at JPL to develop a set of antennas that would provide excellent Radio Occultations performance as well as navigation and ionospheric profiling. This effort is on-going but near completion for the manufacture and delivery of a set of flight antennas for the FORMOSAT-7/COSMIC-2 mission.

  14. 宽带印刷天线与双极化微带及波导缝隙天线阵%Broadband printed antennas and dual-polarized microstrip and waveguide slot antenna arrays

    Institute of Scientific and Technical Information of China (English)

    汪伟

    2006-01-01

    @@ In order to meet the urgent needs in wireless communications, microwave image synthetic aperture radars (SAR), and electronic warfare systems, this dissertation studies several types of broadband dual-polarized planar antenna elements and arrays, and proposes a few of novel designs with experimental verification.The main accomplishments reported in the dissertation are as follows.

  15. Comparison of Antenna Array Systems Using OFDM for Software Radio via the SIBIC Model

    Directory of Open Access Journals (Sweden)

    Robert D. Palmer

    2005-09-01

    Full Text Available This paper investigates the performance of two candidates for software radio WLAN, reconfigurable OFDM modulation and antenna diversity, in an indoor environment. The scenario considered is a 20 m×10 m×3 m room with two base units and one mobile unit. The two base units use omnidirectional antennas to transmit and the mobile unit uses either a single antenna with equalizer, a fixed beamformer with equalizer, or an adaptive beamformer with equalizer to receive. The modulation constellation of the data is QPSK and 16-QAM. The response of the channel at the mobile unit is simulated using a three-dimensional indoor WLAN propagation model that generates multipath components with realistic spatial and temporal correlation. An underlying assumption of the scenario is that existing antenna hardware is available and could be exploited if software processing resources are allocated. The results of the simulations indicate that schemes using more resources outperform simpler schemes in most cases. This implies that desired user performance could be used to dynamically assign software processing resources to the demands of a particular indoor WLAN channel if such resources are available.

  16. Smart antennas in aerospace applications

    OpenAIRE

    Verpoorte, Jaco; Schippers, Harmen; Roeloffzen, Chris G.H.; Marpaung, David A.I.

    2010-01-01

    The interest in Smart Antennas for aerospace applications is growing. This paper describes smart antennas which can be used on aircraft. Two aerospace applications are discussed in more detail: a phased array antenna with optical beam forming and a large vibrating phased array antenna with electronic compensation techniques.

  17. A 60-GHz-band 2 x 4 planar dipole array antenna module fabricated by 3-D SiP technology

    Science.gov (United States)

    Suematsu, Noriharu; Suzuki, Yuya; Yoshida, Satoshi; Tanifuji, Shoichi; Kameda, Suguru; Takagi, Tadashi; Tsubouchi, Kazuo

    2014-08-01

    A 2 × 4 phased array antenna module has been developed for 60-GHz-band short- range high-speed wireless communication terminals. To realize the required vertical distance between the antenna elements, the module is made of five sheets of multi-layered organic substrates vertically stacked with Cu balls, and the 1 x 4 dipole array antenna is placed on both the top and bottom organic substrates. To reduce the mutual coupling between the element antennas, a monolithic microwave integrated circuit (MMIC) is flip-chip mounted on the feed line of each element antenna. The Au-stud bump flip-chip mounting technique helps achieve a lower return loss in the transition section at the MMIC than the Au-wire bonded. The placement accuracy of each antenna element in the vertical direction, 60-GHz signal vertical interconnection between the substrates with Cu balls, and flip-chip mounting of the MMIC are confirmed by 3-D computed tomography (CT) scans.

  18. A True Metasurface Antenna

    OpenAIRE

    Mohamed El Badawe; Almoneef, Thamer S.; Omar M. Ramahi

    2016-01-01

    We present a true metasurface antenna based on electrically-small resonators. The resonators are placed on a flat surface and connected to one feed point using corporate feed. Unlike conventional array antennas where the distance between adjacent antennas is half wavelength to reduce mutual coupling between adjacent antennas, here the distance between the radiating elements is electrically very small to affect good impedance matching of each resonator to its feed. A metasurface antenna measur...

  19. LOPES-3D, an antenna array for full signal detection of air-shower radio emission

    CERN Document Server

    Apel, W D; Bähren, L; Bekk, K; Bertaina, M; Biermann, P L; Blümer, J; Bozdog, H; Brancus, I M; Buchholz, P; Cantoni, E; Chiavassa, A; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Falcke, H; Finger, M; Fuchs, B; Fuhrmann, D; Gemmeke, H; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huber, D; Huege, T; Isar, P G; Kampert, K -H; Kang, D; Krömer, O; Kuijpers, J; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Melissas, M; Morello, C; Oehlschläger, J; Palmieri, N; Pierog, T; Rautenberg, J; Rebel, H; Roth, M; Rühle, C; Saftoiu, A; Schieler, H; Schmidt, A; Schröder, F G; Sima, O; Toma, G; Trinchero, G C; Weindl, A; Wochele, J; Wommer, M; Zabierowski, J; Zensus, J A; 10.1016/j.nima.2012.08.082

    2013-01-01

    To better understand the radio signal emitted by extensive air-showers and to further develop the radio detection technique of high-energy cosmic rays, the LOPES experiment was reconfigured to LOPES-3D. LOPES-3D is able to measure all three vectorial components of the electric field of radio emission from cosmic ray air showers. The additional measurement of the vertical component ought to increase the reconstruction accuracy of primary cosmic ray parameters like direction and energy, provides an improved sensitivity to inclined showers, and will help to validate simulation of the emission mechanisms in the atmosphere. LOPES-3D will evaluate the feasibility of vectorial measurements for large scale applications. In order to measure all three electric field components directly, a tailor-made antenna type (tripoles) was deployed. The change of the antenna type necessitated new pre-amplifiers and an overall recalibration. The reconfiguration and the recalibration procedure are presented and the operationality of...

  20. Theory of light scattering in subwavelength metallic slot antenna array fabricated on subwavelength thin film

    Science.gov (United States)

    Choi, S. B.; Park, D. J.

    2015-10-01

    We demonstrate an analytic model that describes the near-field electromagnetic field profile near a subwavelength-sized metallic slot antenna fabricated on a thin dielectric substrate having a subwavelength thickness reaching λ/1000 in the terahertz frequency region. We found two-dimensional light diffraction induced by the two-dimensional nature of the slot antenna, and back-reflected waves interfered with each other in a complicated manner, resulting in a coupling of the Fourierdecomposed field amplitudes between the diffraction orders along the x and the y directions. We applied these findings to our model by modifying a previously developed model [D. J. Park et al., J. Korean Phys. Soc. 65, 1390 (2014)], and we monitor the effect on far-field transmission. This coupling effect was found to contribute to removal of physically-meaningless spikes or divergences in the transmission spectra, especially for relatively thick substrates.

  1. A Wideband High-Gain Dual-Polarized Slot Array Patch Antenna for WiMAX Applications in 5.8 GHz

    Directory of Open Access Journals (Sweden)

    Amir Reza Dastkhosh

    2012-01-01

    Full Text Available A low-cost, easy-to-fabricate, wideband and high-gain dual-polarized array antenna employing an innovative microstrip slot patch antenna element is designed and fabricated. The design parameters of the antenna are optimized using commercial softwares (Microwave Office and Zeland IE3D to get the suitable -parameters and radiation patterns. Finally, the simulation results are compared to the experimental ones and a good agreement is demonstrated. The antenna has an approximately bandwidth of 14% (5.15–5.9 GHz which covers Worldwide Interoperability Microwave Access (WiMAX/5.8. It also has the peak gain of 26 dBi for both polarizations and high isolation between two ports over a wide bandwidth.

  2. Recirculating photonic filter: a wavelength-selective time delay for phased-array antennas and wavelength code-division multiple access.

    Science.gov (United States)

    Yegnanarayanan, S; Trinh, P D; Jalali, B

    1996-05-15

    A novel wavelength-selective photonic time-delay filter is proposed and demonstrated. The device consists of an optical phased-array waveguide grating in a recirculating feedback configuration. It can function as a true-time-delay generator for squint-free beam steering in optically controlled phased-array antennas and as an encoding-decoding filter for wavelength code-division multiple access. PMID:19876143

  3. Development, manufacture and testing of a planar-array L-band antenna

    Science.gov (United States)

    Frisch, E.; Siegling, H. F.; Fasold, D.

    1981-02-01

    A circularly polarised 1.5 GHz antenna was built and tested for use as an earth coverage antenna for use on board geostationary satellites. A rigid foam panel of extremely low dielectric loss coated with aluminium on the surfaces to give a sandwich effect forms the interior of a TE sub 50 resonator. The slot pattern is etched on one broadside of the skin. During development, sandwich and frame construction methods were evaluated, a structural analysis using NASTRAN performed, and tests for tests for dielectric losses of foams made. Foams were also tested for density variations, tensile strength, and outgassing. Thermal control considerations are given. The rear of the antenna is covered with superinsulation. Far field measurement tests show maximum gain 19.4 dB; gain at edge of earth 15.2 dB; ellipticity at edge of earth 2.5 dB and fundamental resonance 140 Hz. The reduction in gain due to the foam is less than 0.1 dB.

  4. Compact printed two dipole array antenna with a high front-back ratio for ultra-high-frequency radio-frequency identification handheld reader applications

    DEFF Research Database (Denmark)

    Liu, Qi; Zhang, Shuai; He, Sailing

    2015-01-01

    A printed two-dipole array antenna with a high front-back ratio is proposed for ultra-high-frequency (UHF) radio-frequency identification handheld readers. The proposed antenna is a parasitic dual-element array with the ends of both elements folded back towards each other for additional coupling....... The antenna features a compact size of 89 mm × 87 mm and works properly with satisfactory gain and total efficiency in the wide UHF band of 860–960 MHz. Furthermore, the front-to-back ratio of 15–26.8 dB, the peak gain of 3.7–4.4 dBi and the total efficiency of more than 80% in the Federal...

  5. Application of the FD-TD method to the electromagnetic modeling of patch antenna arrays

    Energy Technology Data Exchange (ETDEWEB)

    Pasik, M.F. [Sandia National Labs., Albuquerque, NM (United States); Aguirre, G.; Cangellaris, A.C. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Electrical and Computer Eengineering, Center for Electronic Packaging Research

    1996-01-10

    FD-TD method and the Berenger Perfectly Matched Layer (PML) absorbing condition are applied to the modeling of a 32-element patch array. Numerical results for the return loss at the array feed are presented and compared to measured results for the purpose of model validation.

  6. Design of Circularly-Polarised, Crossed Drooping Dipole, Phased Array Antenna Using Genetic Algorithm Optimisation

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal

    2007-01-01

    A printed drooping dipole array is designed and constructed. The design is based on a genetic algorithm optimisation procedure used in conjunction with the software programme AWAS. By optimising the array G/T for specific combinations of scan angles and frequencies an optimum design is obtained...

  7. Crystalline colloidal array hydrogel materials: From synthesis to applications

    Science.gov (United States)

    Liu, Lei

    This dissertation is focused on the synthesis, characterization, and applications of crystalline colloidal array (CCA) hydrogel materials. CCA are three dimensional periodic structures formed by the electrostatic self-assembly of monodisperse macroionic colloidal spheres in an aqueous medium. CCA dispersions efficiently Bragg diffract light in the near UV to near IR spectral region, and are useful in areas of optical device fabrication, chemical sensing devices, and novel separation materials. We developed methodologies to synthesize monodisperse colloidal silica spheres via hydrolysis and condensation of tetraethoxysilane in nonionic reverse microemulsion systems. We examined the effects of reaction parameters and surfactant hydrophilic-lipophilic-balance (HLB) number on the final particle size and size distribution. We developed a unique multi-step growth technique by which the final particle diameter can be continuously selected with extremely narrow size distributions over a broad size range. We also developed methodologies to surface functionalize silica spheres to increase the particle surface charge density by two orders of magnitude. The resulting dispersions readily self-assemble into CCA and Bragg diffract light over a broad concentration range. In addition, we discovered an anomalously intense secondary diffraction phenomenon from CCA which occurs due to the superimposed Bragg diffraction from numerous lattice planes. This was quantitatively modeled by using dynamical diffraction and light scattering theory. We extended the microemulsion synthesis methodologies to fabricate monodisperse SiOsb2/CdS composite spheres with well-controlled and complex morphologies. By controlling the co-precipitation process, CdS could be incorporated into silica spheres as quantum dots, as large inclusions, as surface patches and welds, or as shells or cores. Further processing of these materials by selectively etching out CdS templates also generated a series of porous

  8. Broadband impedance-matched near-zero-index metamaterials for a wide scanning phased array antenna design

    International Nuclear Information System (INIS)

    We present broadband near-zero-index metamaterials composed of dielectric resonators and metallic rods, whose permittivity ε and permeability μ are near-zero simultaneously. It is notable that the values of permittivity ε are equal to those of permeability μ over a broadband frequency range of 8.45 GHz to 10.5 GHz, indicating the impedances of the proposed near-zero-index metamaterials match vacuum in this broadband. The broadband near-zero-index metamaterials for manipulating radiation sources are analyzed. We also demonstrate numerically that such near-zero-index metamaterials can offer a unique grating condition in a phased array antenna, with the beam scanning angle range beyond the critical angle limit of the grating lobe. (paper)

  9. Silicon-Based Antenna-Coupled Polarization-Sensitive Millimeter-Wave Bolometer Arrays for Cosmic Microwave Background Instruments

    CERN Document Server

    Rostem, Karwan; Appel, John W; Bennett, Charles L; Brown, Ari; Chang, Meng-Ping; Chuss, David T; Colazo, Felipe A; Costen, Nick; Denis, Kevin L; Essinger-Hileman, Tom; Hu, Ron; Marriage, Tobias A; Moseley, Samuel H; Stevenson, Thomas R; U-Yen, Kongpop; Wollack, Edward J; Xu, Zhilei

    2016-01-01

    We describe feedhorn-coupled polarization-sensitive detector arrays that utilize monocrystalline silicon as the dielectric substrate material. Monocrystalline silicon has a low-loss tangent and repeatable dielectric constant, characteristics that are critical for realizing efficient and uniform superconducting microwave circuits. An additional advantage of this material is its low specific heat. In a detector pixel, two Transition-Edge Sensor (TES) bolometers are antenna-coupled to in-band radiation via a symmetric planar orthomode transducer (OMT). Each orthogonal linear polarization is coupled to a separate superconducting microstrip transmission line circuit. On-chip filtering is employed to both reject out-of-band radiation from the upper band edge to the gap frequency of the niobium superconductor, and to flexibly define the bandwidth for each TES to meet the requirements of the application. The microwave circuit is compatible with multi-chroic operation. Metalized silicon platelets are used to define th...

  10. Gimbals Drive and Control Electronics Design, Development and Testing of the LRO High Gain Antenna and Solar Array Systems

    Science.gov (United States)

    Chernyakov, Boris; Thakore, Kamal

    2010-01-01

    Launched June 18, 2009 on an Atlas V rocket, NASA's Lunar Reconnaissance Orbiter (LRO) is the first step in NASA's Vision for Space Exploration program and for a human return to the Moon. The spacecraft (SC) carries a wide variety of scientific instruments and provides an extraordinary opportunity to study the lunar landscape at resolutions and over time scales never achieved before. The spacecraft systems are designed to enable achievement of LRO's mission requirements. To that end, LRO's mechanical system employed two two-axis gimbal assemblies used to drive the deployment and articulation of the Solar Array System (SAS) and the High Gain Antenna System (HGAS). This paper describes the design, development, integration, and testing of Gimbal Control Electronics (GCE) and Actuators for both the HGAS and SAS systems, as well as flight testing during the on-orbit commissioning phase and lessons learned.

  11. Sum-type Kaiser-Bessel windows for apodized antenna arrays

    OpenAIRE

    Anukhin, I. P.; Lukin, V. V.; Ponomarenko, N. N.; Zelensky, A. A.; Saramaki, Tapio; Zbaida, K.

    1997-01-01

    A class of sum-type Kaiser-Bessel windows is introduced. These windows are optimized for improving the performance of apodized array patterns. Compared with the basic Kaiser-Bessel windows, the proposed windows are shown provide several benefits.

  12. A comparative study of feed impedances of a circular and three different spiral antenna arrays

    Science.gov (United States)

    Ramachandra, V.; Dey, K. K.; Khastgir, P.

    1982-08-01

    Mathematical derivation of feed impedances of the dipole radiators of a circular and three different spiral arrays has been made for both constant and progressive phase distributions. A set of graphs, which show the variations of these impedances and their components from radiator to radiator, has been obtained. Spiral distributions of impedances can be observed on the Argand diagram in the cases of the three spiral arrays.

  13. Comparison of steering angle and bandwidth for various phased array antenna concepts

    Science.gov (United States)

    Bonjour, Romain; Singleton, Matthew; Leuchtmann, Pascal; Leuthold, Juerg

    2016-08-01

    In this paper we compare different integratable ultra-fast tunable true-time delay concepts with respect to their performances in a phased array system. The performances of the schemes are assessed with respect to the supported range, i.e. the range within which beam steering for a given fractional bandwidth can be achieved with a gain flatness better than 3 dB. We also compare the array gain as of function of steering angle and fractional bandwidth.

  14. High efficiency and dual polarized array antenna for satellite communication application

    Science.gov (United States)

    Liu, Ningmin

    2009-12-01

    In this paper, we describe a flat plate array for the satellite communication receiver, with small aperture, high efficiency and low cross polarization levels. The radiating element used is circular waveguide which is probe-fed using a stripline distribution networks providing uniform excitations to the 4×4 array. The networks are placed one behind the other for dual polarized purposes. The array is composed of 2×1 subarrays. The overall array thickness is about 1λ ( λ is the wavelength of the center frequency), and the array aperture is about 3.2λ. Simulated results on a Ku-band prototype are discussed. The bandwidth (VSWR below 2.0) is about 500MHz, cross-polarized radiation from both ports is below -35dB, the isolation between the ports is below -25dB, and the gain of the 4×4 array is about 20dBi. Simulated efficiency is about 75% (including the stripline feed networks).

  15. Linear Array Geometry Synthesis with Minimum Side Lobe Level and Null Control Using Dynamic Multi-Swarm Particle Swarm Optimizer with Local Search

    Science.gov (United States)

    Ghosh, Pradipta; Zafar, Hamim

    Linear antenna array design is one of the most important electromagnetic optimization problems of current interest. This paper describes the synthesis method of linear array geometry with minimum side lobe level and null control by the Dynamic Multi-Swarm Particle Swarm Optimizer with Local Search (DMSPSO) which optimizes the spacing between the elements of the linear array to produce a radiation pattern with minimum side lobe level and null placement control. The results of the DMSPSO algorithm have been shown to meet or beat the results obtained using other state-of-the-art metaheuristics like the Genetic Algorithm (GA),General Particle Swarm Optimization (PSO), Memetic Algorithms (MA), and Tabu Search (TS) in a statistically meaningful way. Three design examples are presented that illustrate the use of the DMSPSO algorithm, and the optimization goal in each example is easily achieved.

  16. LOPES-3D: An antenna array for full signal detection of air-shower radio emission

    International Nuclear Information System (INIS)

    To better understand the radio signal emitted by extensive air-showers and to further develop the radio detection technique of high-energy cosmic rays, the LOPES experiment was reconfigured to LOPES-3D. LOPES-3D is able to measure all three vectorial components of the electric field of radio emission from cosmic ray air showers. The additional measurement of the vertical component ought to increase the reconstruction accuracy of primary cosmic ray parameters like direction and energy, provides an improved sensitivity to inclined showers, and will help to validate simulation of the emission mechanisms in the atmosphere. LOPES-3D will evaluate the feasibility of vectorial measurements for large scale applications. In order to measure all three electric field components directly, a tailor-made antenna type (tripoles) was deployed. The change of the antenna type necessitated new pre-amplifiers and an overall recalibration. The reconfiguration and the recalibration procedure are presented and the operationality of LOPES-3D is demonstrated.

  17. A Fast MoM Calculation Technique Using Sinusoidal Basis and Testing Functions for a Wire on a Dielectric Substrate and Its Application to Meander Loop and Grid Array Antennas

    OpenAIRE

    Nakano, Hisamatsu; Kawano, Toru; Kozono, Yousuke; Yamauchi, Junji

    2005-01-01

    The input impedance matrix element of the method of moments (MoM) for an arbitrarily shaped wire antenna printed on a dielectric material Zm,n is formulated to be composed of three terms Zψsm,n, Zψm,n, and ΔZm,n involving single-, double-, and triple-integral calculations, respectively. The MoM based on the Zm,n formulated in this paper (new MoM) is applied to two antennas-a meander loop antenna and a grid array antenna-as well as a simple loop used as a reference antenna. The computation tim...

  18. Radiation pattern synthesis of planar antennas using the iterative sampling method

    Science.gov (United States)

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

    1975-01-01

    A synthesis method is presented for determining an excitation of an arbitrary (but fixed) planar source configuration. The desired radiation pattern is specified over all or part of the visible region. It may have multiple and/or shaped main beams with low sidelobes. The iterative sampling method is used to find an excitation of the source which yields a radiation pattern that approximates the desired pattern to within a specified tolerance. In this paper the method is used to calculate excitations for line sources, linear arrays (equally and unequally spaced), rectangular apertures, rectangular arrays (arbitrary spacing grid), and circular apertures. Examples using these sources to form patterns with shaped main beams, multiple main beams, shaped sidelobe levels, and combinations thereof are given.

  19. Decoupling and matching network for monopole antenna arrays in ultrahigh field MRI

    Science.gov (United States)

    Zhang, Xiaoliang

    2015-01-01

    Background Radiative coil arrays, e.g., dipole or monopole arrays, are increasingly used in MR signal excitation and reception for ultrahigh field MRI. Technically, it is challenging to suppress the electromagnetic (EM) coupling of radiative array elements due to their unique structures. Methods In this study, we proposed a combined decoupling and matching network (DMN) for monopole arrays for MRI applications. Compared with separate decoupling network and matching network, the combined network proposed here needs less components and rather suitable for decoupling radiative arrays in MRI. Results Our study shows that the transmission coefficient between two coupled monopoles can be reduced from −5 dB to −24.8 dB by using the combined DMN. It is also clearly demonstrated in this study that this decoupling method is a port decoupling method rather than an element decoupling method. Conclusions With the proposed DMN, the monopole coil provides locally strong and spatially diverse B1 fields, which is essential to the improvement of MR sensitivity and parallel imaging performance. PMID:26435918

  20. Study on Realizing Isolation between Receiver and Transmitter at Array Antenna%阵列天线收发隔离技术

    Institute of Scientific and Technical Information of China (English)

    张焕斌; 汪立新

    2013-01-01

    The array antenna is widely applied in communication field. A group of antenna will have lots of input, while the self-excited phenomenon is objectively existed. The conventional way only works on a single role. It will consume lots of hardware resources to filter each role of array antenna with a single filter so that it is unavailable. This paper proposes a scheme to use parallel delay on 16 road input array antenna which will cancelling the echo signal. It will effectively reduce the hardware resources when this parallel structure is used.%阵列天线在通信领域应用非常广泛,常规的收发隔离技术只是针对一路信号进行回波信号的抑制,假如套用常规方案对阵列天线的每一路输入进行一次自适应抵消将会大量消耗硬件资源,在实际操作中是不可行的,提出一种运用并行延时方案对16路输入的阵列天线进行回波信号抑制工作.利用这种并列式的结构可以有效的减少硬件消耗.

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

    OpenAIRE

    Lera Acedo, Eloy de

    2010-01-01

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

  2. A Modular Approach to FEM-MOM Hybridization for the Analysis of Finite Arrays of Antennas

    OpenAIRE

    García Castillo, Luis Emilio; Andres, Belen; Gómez Revuelto, Ignacio; García Muñoz, Luis Enrique; Craeye, Cristophe

    2010-01-01

    A modular approach is proposed to combine MoM and FEM for the fast analysis of finite arrays. The hybridization of MOM with FEM is obtained by using FEM to produce primary and secondary Macro Basis Functions (MBFs). A special mesh truncation technique based on domain decomposition is used. Once the MBFs are obtained, the finite array is solved via a reduced MOM problem with the MBFs so obtained as basis functions. The implementations of MOM+MBF and FEM methods are made in separate codes using...

  3. A COMPARATIVE STUDY OF PATTERN SYNTHESIS OF NONUNIFORM CIRCULAR ARRAYS USING FIREFLY, BAT AND CUCKOO SEARCH ALGORITHMS

    OpenAIRE

    T Pavani; Dr.G.S.N.Raju; Dr. P.V. Sridevi

    2014-01-01

    In the present work, a design problem of nonuniform circular array antennas to achieve minimum sidelobe level and high directivity with beam width constraint is presented. The three most recent nature inspired metaheuristics: Firefly (FA), Bat and Cuckoo search (CS) algorithms are used to determine an optimum set of excitation amplitudes and antenna inter element separations. Three different instances of the circular array deign problem is considered. Radiation Patterns are computed and numer...

  4. Solution-Liquid-Solid Synthesis of Hexagonal Nickel Selenide Nanowire Arrays with a Nonmetal Catalyst.

    Science.gov (United States)

    Xu, Kun; Ding, Hui; Jia, Kaicheng; Lu, Xiuli; Chen, Pengzuo; Zhou, Tianpei; Cheng, Han; Liu, Si; Wu, Changzheng; Xie, Yi

    2016-01-26

    Inorganic nanowire arrays hold great promise for next-generation energy storage and conversion devices. Understanding the growth mechanism of nanowire arrays is of considerable interest for expanding the range of applications. Herein, we report the solution-liquid-solid (SLS) synthesis of hexagonal nickel selenide nanowires by using a nonmetal molecular crystal (selenium) as catalyst, which successfully brings SLS into the realm of conventional low-temperature solution synthesis. As a proof-of-concept application, the NiSe nanowire array was used as a catalyst for electrochemical water oxidation. This approach offers a new possibility to design arrays of inorganic nanowires. PMID:26695560

  5. Influence of the plasma profile and the antenna geometry on the matching and current distribution control of the ITER ICRF antenna array. Optimization of the decoupling-matching system

    International Nuclear Information System (INIS)

    Highlights: ► Analysis of the matching-decoupling system of the ICRF antenna array of ITER. ► Control of the array phasing by the decouplers for the same power of power sources. ► Computation for the 2012 design status of the antenna plug. ► 7 decouplers needed but 10 can be used to decrease the ratings of components. ► Effects of plasma profile and antenna geometry. -- Abstract: The eight triplets of straps of the ITER ICRF antenna array are fed through 8 matching circuits and 4 hybrids to ensure load resilience. Decouplers are used to mitigate the effects of triplet mutual coupling. They also control the array phasing. The electrical constraints on the decouplers for different layouts with heating (H) or current drive (CD) phasing are compared starting from the TOPICA matrix computed for the last antenna plug design and the reference (most pessimistic) plasma profile “2010low” provided by IO. It is shown that this last profile provides a significant decrease of plasma coupling and increase of mutual coupling with respect to the previous reference profile “Sc2short17”. This results in a larger range of decoupler reactance Xdec and voltage VXdec needed. This range can be reduced when using 10 decouplers instead of the 7 needed for the same forward power PGk+ of the 4 power sources. For H phasing only 4 decouplers could be used but with different PGk+ (PGk+ ratio up to 1.5–2.5). For CD phasing and same plasma profile the power capability Ptot is increased by 25% with a decoupler layout allowing much smaller poloidal phasing than the 90° provided by the hybrids. A decrease of the distance antenna-plasma profile reduces the normalized decoupler voltage VXdec/√Ptot with no significant change of the Xdec range. The recess of the vertical septa between the strap boxes increases the plasma coupling but has the drawback of also increasing the mutual coupling between triplets: the needed range of Xdec and of VXdec/√Ptot is increased in proportion

  6. Influence of the plasma profile and the antenna geometry on the matching and current distribution control of the ITER ICRF antenna array. Optimization of the decoupling-matching system

    Energy Technology Data Exchange (ETDEWEB)

    Messiaen, A., E-mail: a.messiaen@fz-juelich.de [LPP-ERM/KMS, EURATOM-Belgian State Association, TEC Partner, CYCLE, B-1000 Brussels (Belgium); Swain, D. [US ITER Team, ORNL (United States); Vervier, M.; Dumortier, P.; Durodié, F.; Grine, D. [LPP-ERM/KMS, EURATOM-Belgian State Association, TEC Partner, CYCLE, B-1000 Brussels (Belgium)

    2013-10-15

    Highlights: ► Analysis of the matching-decoupling system of the ICRF antenna array of ITER. ► Control of the array phasing by the decouplers for the same power of power sources. ► Computation for the 2012 design status of the antenna plug. ► 7 decouplers needed but 10 can be used to decrease the ratings of components. ► Effects of plasma profile and antenna geometry. -- Abstract: The eight triplets of straps of the ITER ICRF antenna array are fed through 8 matching circuits and 4 hybrids to ensure load resilience. Decouplers are used to mitigate the effects of triplet mutual coupling. They also control the array phasing. The electrical constraints on the decouplers for different layouts with heating (H) or current drive (CD) phasing are compared starting from the TOPICA matrix computed for the last antenna plug design and the reference (most pessimistic) plasma profile “2010low” provided by IO. It is shown that this last profile provides a significant decrease of plasma coupling and increase of mutual coupling with respect to the previous reference profile “Sc2short17”. This results in a larger range of decoupler reactance X{sub dec} and voltage V{sub Xdec} needed. This range can be reduced when using 10 decouplers instead of the 7 needed for the same forward power P{sub Gk+} of the 4 power sources. For H phasing only 4 decouplers could be used but with different P{sub Gk+} (P{sub Gk+} ratio up to 1.5–2.5). For CD phasing and same plasma profile the power capability P{sub tot} is increased by 25% with a decoupler layout allowing much smaller poloidal phasing than the 90° provided by the hybrids. A decrease of the distance antenna-plasma profile reduces the normalized decoupler voltage V{sub Xdec}/√P{sub tot} with no significant change of the X{sub dec} range. The recess of the vertical septa between the strap boxes increases the plasma coupling but has the drawback of also increasing the mutual coupling between triplets: the needed range of X

  7. Theory of a Traveling Wave Feed for a Planar Slot Array Antenna

    Science.gov (United States)

    Rengarajan, Sembiam

    2012-01-01

    Planar arrays of waveguide-fed slots have been employed in many radar and remote sensing applications. Such arrays are designed in the standing wave configuration because of high efficiency. Traveling wave arrays can produce greater bandwidth at the expense of efficiency due to power loss in the load or loads. Traveling wave planar slot arrays may be designed with a long feed waveguide consisting of centered-inclined coupling slots. The feed waveguide is terminated in a matched load, and the element spacing in the feed waveguide is chosen to produce a beam squinted from the broadside. The traveling wave planar slot array consists of a long feed waveguide containing resonant-centered inclined coupling slots in the broad wall, coupling power into an array of stacked radiating waveguides orthogonal to it. The radiating waveguides consist of longitudinal offset radiating slots in a standing wave configuration. For the traveling wave feed of a planar slot array, one has to design the tilt angle and length of each coupling slot such that the amplitude and phase of excitation of each radiating waveguide are close to the desired values. The coupling slot spacing is chosen for an appropriate beam squint. Scattering matrix parameters of resonant coupling slots are used in the design process to produce appropriate excitations of radiating waveguides with constraints placed only on amplitudes. Since the radiating slots in each radiating waveguide are designed to produce a certain total admittance, the scattering (S) matrix of each coupling slot is reduced to a 2x2 matrix. Elements of each 2x2 S-matrix and the amount of coupling into the corresponding radiating waveguide are expressed in terms of the element S11. S matrices are converted into transmission (T) matrices, and the T matrices are multiplied to cascade the coupling slots and waveguide sections, starting from the load end and proceeding towards the source. While the use of non-resonant coupling slots may provide an

  8. A Combined Antenna Arrays and Reverse-Link Synchronous DS-CDMA System over Frequency-Selective Fading Channels with Power Control Error

    Directory of Open Access Journals (Sweden)

    Yong-Seok Kim

    2004-08-01

    Full Text Available An improved antenna array (AA has been introduced, in which reverse-link synchronous transmission technique (RLSTT is incorporated to effectively make better an estimation of covariance matrices at a beamformer-RAKE receiver. While RLSTT is effective in the first finger at the RAKE receiver in order to reject multiple-access interference (MAI, the beamformer estimates the desired user's complex weights, enhancing its signal and reducing cochannel interference (CCI from the other directions. In this work, it is attempted to provide a comprehensive analysis of user capacity which reflects several important factors such as the shape of multipath intensity profile (MIP, the number of antennas, and power control error (PCE. Theoretical analysis, confirmed by the simulations, demonstrates that the orthogonality provided by employing RLSTT along with AA may make the DS-CDMA system insensitive to the PCE even with fewer numbers of antennas.

  9. On the design of a planar phased array radar antenna architecture for space debris situational awareness

    OpenAIRE

    Garcia-Gasco Trujillo, Javier; Noval Sánchez de Toca, Alvaro; Montesinos Ortego, Ignacio; Fernández González, José Manuel; Sierra Pérez, Manuel

    2013-01-01

    The Space Situational Awareness (SSA) program from the European Space Agency (ESA) protects Europe's citizens and their satellite-based services by detecting space hazards. ESA Ground Systems (GS) division is currently designing a phased array radar composed of thousands of radiating elements for future stages of the SSA program [1]. The radar shall guarantee the detection of most of the Low Earth Orbit (LEO) space debris, providing a general map of space junk. While range accuracy is mainly ...

  10. Nature-inspired Cuckoo Search Algorithm for Side Lobe Suppression in a Symmetric Linear Antenna Array

    OpenAIRE

    Abdul Rani, K. N.; M. F. Abdul Malek; N. Siew-Chin

    2012-01-01

    In this paper, we proposed a newly modified cuckoo search (MCS) algorithm integrated with the Roulette wheel selection operator and the inertia weight controlling the search ability towards synthesizing symmetric linear array geometry with minimum side lobe level (SLL) and/or nulls control. The basic cuckoo search (CS) algorithm is primarily based on the natural obligate brood parasitic behavior of some cuckoo species in combination with the Levy flight behavior of some birds and fruit flies....

  11. FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

    OpenAIRE

    James Millar; Steven D. Blostein; Constantin Siriteanu

    2006-01-01

    Field-programmable gate arrays (FPGAs) are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs), through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs). In our study, we employ an Altera Stratix FPGA development board, along with the DSP Bu...

  12. ETC用5.835GHz微带阵列天线的设计%5.835 GHz microstrip array antenna used in ETC

    Institute of Scientific and Technical Information of China (English)

    邵一鹏; 白明; 马慧瑾; 苗俊刚

    2012-01-01

    A low-sirlclobe circularly-polarized microstrip array antenna used in road side unit (RSU) for electronic toll collection (ETC) was designed. In order to achieve the effect of low-sidelobe circular polarization and low axial ratio, two microstrip antenna units was modified with the rotation and phase compensation methods to reduce axial ratio. The improved two units is taken as a radiative unit to make a microstrip antenna array, whose amplitude distribution is based on DolphChebyshev. The simulation and measured results indicate that the antenna has the effect of low-sidelobe and circular polarization. The antenna system has a good theoretical and practical significance for ETC and other similar antenna systems.%设计了一种ETC用低旁瓣圆极化微带阵列天线,应用于电子收费(ETC)的路测单元(RSU).为实现低旁瓣、圆极化的效果.对2个微带天线单元运用旋转与相位补偿的方法进行轴比改进,并以改进后的2单元作为辐射单元制作了一款基于道尔夫-切比雪夫幅度分布的微带天线阵列.经过仿真与实际测量,该天线具有很好的低旁瓣、圆极化的效果.该天线对于ETC系统以及其他类似的天线系统具有很好的理论与实际意义.

  13. Design and Analysis of Printed Yagi-Uda Antenna and Two-Element Array for WLAN Applications

    OpenAIRE

    Cai Run-Nan; Yang Ming-Chuan; Lin Shu; Zhang Xing-Qi; Zhang Xin-Yue; Liu Xiao-Feng

    2012-01-01

    A printed director antenna with compact structure is proposed. The antenna is fed by a balanced microstrip-slotline and makes good use of space to reduce feeding network area and the size of antenna. According to the simulation results of CST MICROWAVE STUDIO software, broadband characteristics and directional radiation properties of the antenna are explained. The operating bandwidth is 1.8 GHz–3.5 GHz with reflection coefficient less than −10 dB. Antenna gain in band can achieve 4.5–6.8 dBi,...

  14. Research on Circularly Polarized Single Pulse Millimeter-Wave Array Antenna%毫米波圆极化单脉冲阵列天线的研究

    Institute of Scientific and Technical Information of China (English)

    赵爽; 陈殿仁

    2011-01-01

    A single-element circularly polarized microstrip patch antenna was analyzed based on the cavity-mode theory. By studying the design method of the circular polarized microstrip array antenna, a 64 element circularly polarized microstrip array antenna with sum-difference network which worked at 35. 75 GHz was designed. It was simulated and optimized by the HFSS. Experiment result shows that the antenna provides the gain of 21dB and good axial ratio . The different beam has a zero depth better than 20dB.%在腔模理论基础上分析了单阵元圆极化微带贴片天线,研究了圆极化微带阵列天线的设计方法,采用相位旋转法设计了中心频率为35.75GHz的64元圆极化微带阵列天线与平面和差结构,使天线和和差馈电处于一个平面.利用Ansoft公司的HFSS软件进行了仿真优化.经过对天线实物的测试,此天线提供了21dB的增益,具有良好的轴比和驻波比,差波束零值深度大于20dB.

  15. Log-Periodic Dipole Array Antenna as a Chipless Radio-Frequeny Identification (RFID) Tag

    CERN Document Server

    Gupta, Shulabh; Roberts, Robert Chris; Jiang, Li Jun

    2013-01-01

    A passive chipless Radio-frequency identification (RFID) tag based on log-periodic (LP) dipole array is proposed, where the tailorable band-rejection property of the LP aperture is utilized to realize large number of codes. The proposed tag principle is successfully validated using measurements, where the absence and presence of the band-rejection, is shown to carry the bit information. Its fabrication simplicity is also demonstrated by its implementation on a flexible substrate. Finally, two different tag formation schemes, based on specific set of resonance suppressions, are discussed in detailed.

  16. Higher Order Mode Coupling in Feed Waveguide of a Planar Slot Array Antenna

    Science.gov (United States)

    Rengarajan, Sembiam

    2011-01-01

    A simple technique was developed to account for the higher order mode coupling between adjacent coupling slots in the feed waveguide of a planar slot array. The method uses an equation relating the slot impedance to the slot voltage and a reaction integral involving the equivalent magnetic current of the slot aperture and the magnetic field coupled from an adjacent slot. In the proposed method, one uses the Elliott s design technique to determine tilt angles and lengths of the coupling slots. The radiating slots are modeled as shunt admittances, and the coupling slots are modeled as series impedances.

  17. The Noise Performance of a Multiple-Input-Port and Multiple-Output-Port Low-Noise Amplifier Connected to an Array of Coupled Antennas

    OpenAIRE

    Evelyne Clavelier; Frédéric Broydé

    2011-01-01

    We address the noise characterization of a multiple-input-port and multiple-output-port (MIPMOP) device receiving signals from an array of antennas. A definition of the noise figures and natural noise figures of a MIPMOP device is provided, and the resulting properties are detailed in the impedance and admittance representations. We compute the natural noise figures of a low-noise MIPMOP amplifier comprising a MIMO series-series feedback amplifier (MIMO-SSFA), designed for a wireless receiver...

  18. Mast-antenna survivability : structural dynamic design analysis by component mode synthesis

    OpenAIRE

    Petersen, Lynn James

    1994-01-01

    Approved for public release; distribution is unlimited The structural survivability of shipboard mast/antenna systems subjected to underwater explosion can be designed in, through the determination of the structural dynamics of the mast/antenna system. This thesis details the specialized application of accurate and efficient analytic methods for the structural dynamic design analysis of shipboard mast/antenna systems. Investigated herein are a class of substructuring methods, generally ref...

  19. C-band 6-bit phase shifter for a phase array antenna

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaofeng; Shi Jiangyi

    2013-01-01

    A C-band 6-bit digital phase shifter is presented.The phase shifter is based on the synthetic design of a high-pass/low-pass network and the all-pass network.The series scatter restrain method is also discussed.The phase shifter is fabricated in 0.25μm GaAs PHEMT technology and developed for C-band phased arrays,and the relative phase shift varies from 0 to 360 in step of 5.625°.The phase shifter,with a chip size of 4 × 1.95 mm2,has achieved an insertion loss better than 6.4 dB,RMS phase error of less than 1.73°,and an input and output VSWR less than 1.6 at all conditions.

  20. Motion Compensation for Airborne Forward Looking Synthetic Aperture Radar with Linear Array Antennas%机载前视阵列SAR运动补偿研究

    Institute of Scientific and Technical Information of China (English)

    张英杰; 王彦平; 谭维贤; 洪文

    2013-01-01

      Combined with Frequency-Modulated Continuous-Wave (FMCW) technology, airborne forward-looking Synthetic Aperture Radar (SAR) with linear array antennas can obtain the images in front of an aircraft, while having the advantages of FMCW radar such as small size and lightweight. Moreover, it is suitable for installation on platforms such as helicopters and small unmanned aerial vehicles. In practice, motion compensation for forward-looking SAR with linear array antennas is one of the key problems to obtaining the images in front of aircraft. This paper uses linear array antennas to analyses the influence of motion error in aircraft on an echo model based on the geometry of forward looking SAR, with linear array antennas, and proposes a motion compensation scheme. Moreover, the compensation scheme is applied to an improved Frequency Scaling Algorithm (FSA) for FMCW forward looking SAR with linear array antennas. Finally, the compensation scheme is verified using simulations.%  结合调频连续波(FMCW)技术的机载前视阵列合成孔径雷达(SAR)既能够获取飞机前下方区域图像,又具有FMCW体制雷达体积小、重量轻的优势,易于安装在直升机等轻小型平台。前视阵列SAR的运动补偿是获得前视图像信息的关键问题之一。该文根据前视阵列SAR的几何模型,分析了载机平台运动误差对回波的影响,研究了相应的运动补偿方法。在此基础上,将补偿方法嵌入到一种基于FMCW的前视阵列SAR的改进频率变标算法(FSA)中。最后通过仿真实验验证了该补偿方法的有效性。

  1. Side-looking image formation with a maneuvering vehicle-mounted antenna array

    Science.gov (United States)

    Ranney, Kenneth; Nguyen, Lam; Koenig, Francois; Kirose, Getachew; Martone, Anthony; Mazzaro, Gregory; Sherbondy, Kelly; Tran, Chi; Kappra, Karl

    2011-06-01

    Researchers at the U.S. Army Research Laboratory (ARL) designed and fabricated the Synchronous Impulse REconstruction (SIRE) radar system in an effort to address fundamental questions about the utilization of low frequency, ultrawideband (UWB) radar. The SIRE system includes a receive array comprising 16 receive channels, and it is capable of operating in either a forward-looking or a side-looking mode. When operated in side-looking mode, it is capable of producing high-resolution Synthetic Aperture Radar (SAR) data. The SAR imaging algorithms, however, initially operated under the assumption that the vehicle followed a nearly linear trajectory throughout the data collection. Under this assumption, the introduction of vehicle path nonlinearities distorted the processed SAR imagery. In an effort to mitigate these effects, we first incorporated segmentation routines to eliminate highly non-linear portions of the path. We then enhanced the image formation algorithm, enabling it to process data collected from a non-linear vehicle trajectory. We describe the incorporated segmentation approaches and compare the imagery created before and after their incorporation. Next, we describe the modified image formation algorithm and present examples of output imagery produced by it. Finally, we compare imagery produced by the initial segmentation algorithm to imagery produced by the modified image-formation algorithm, highlighting the effects of segmentation parameter variation on the final SAR image.

  2. Implementation of a Novel Low-Cost Low-Profile Ku-Band Antenna Array for Single Beam Steering from Space

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix A.

    2013-01-01

    Phased array antennas afford many advantages over traditional reflector antennas due to their conformality, high aperture efficiency, and unfettered beam steering capability at the price of increased cost and complexity. This paper eliminates the complex and costly array backend via the implementation of a series fed array employing a propagation constant reconfigurable transmission line connecting each element in series. Scanning can then be accomplished through one small (less than or equal to 100mil) linear motion that controls propagation constant. Specifically, each element is fed via a reconfigurable coplanar stripline transmission line with a tapered dielectric insert positioned between the transmission line traces. The dielectric insert is allowed to move up and down to control propagation constant and therefore induce scanning. We present a 20 element patch array design, scanning from -25 deg. less than or equal to theta less than or equal to 21 deg. at 13GHz. Measurements achieve only10.5 deg. less than or equal to theta less than or equal to 22 deg. scanning due to a faulty, yet correctable, manufacturing process. Beam squint is measured to be plus or minus 3 deg. for a 600MHz bandwidth. This prototype was improved to give scanning of 3.5 deg. less than or equal to theta less than or equal to 22 deg. Cross-pol patterns were shown to be -15dB below the main beam. Simulations accounting for fabrication errors match measured patterns, thus validating the designs.

  3. A curl antenna

    OpenAIRE

    Nakano, Hisamatsu; Okuzawa, Shigeru; Ohishi, Katsumi; Mimaki, Hiroaki; Yamauchi, Junji

    1993-01-01

    A radiation element, designated as a curl antenna, is proposed for a circularly polarized antenna. The radiation characteristics of the curl are numerically analyzed. The gain is approximately 8.4 dB, and the 3-dB axial ratio criterion is 6.7%. Two aspects of curl array antennas are also presented: a decoupling factor between two curls and a circular array antenna consisting of 168 curls. Calculations show how the decoupling factor depends on the relative rotation angle of the two curls. The ...

  4. Antennas - Our electronic eyes and ears

    Science.gov (United States)

    Kraus, John D.

    1989-01-01

    Although the number of antenna types is vast, all antenna properties may be characterized in terms of the same basic parameters of radiation pattern, impedance, radar cross-section, and temperature. A comprehensive introduction is presented to antenna configurations; these encompass, among antennas constructed of wire or tubing, such wideband and circularly polarized types as helices, linear conductors, and loops. Sheet-conductor antenna families include reflectors, waveguides, and slotted antennas. Nonconducting dielectric antennas are lenses, polyrods, and slabs. Antenna array types range over 'driven', parasitic, and adaptive configurations. 'Two half-wavelength' and 'four half-wavelength' element arrays are also discussed.

  5. A COMPARATIVE STUDY OF PATTERN SYNTHESIS OF NONUNIFORM CIRCULAR ARRAYS USING FIREFLY, BAT AND CUCKOO SEARCH ALGORITHMS

    Directory of Open Access Journals (Sweden)

    T Pavani

    2014-09-01

    Full Text Available In the present work, a design problem of nonuniform circular array antennas to achieve minimum sidelobe level and high directivity with beam width constraint is presented. The three most recent nature inspired metaheuristics: Firefly (FA, Bat and Cuckoo search (CS algorithms are used to determine an optimum set of excitation amplitudes and antenna inter element separations. Three different instances of the circular array deign problem is considered. Radiation Patterns are computed and numerical results obtained with each algorithm are presented. A comparative evaluation of the three proposed algorithms regarding their applicability as numerical optimization techniques is illustrated.

  6. Electrochemical synthesis and crystal structure of ordered arrays of Со – nanotubes

    Directory of Open Access Journals (Sweden)

    Artem Kozlovskiy

    2015-09-01

    Full Text Available In this paper, using the method of electrochemical template synthesis, ordered arrays of metallic nanostructures on the basis of cobalt with various dimensions (180-380 nm were obtained. The diameter of Co-nanotubes was controlled by original polymer matrix, which provided to prepare arrays consisting of individually standing cobalt nanotubes. The crystal structure of the synthesized samples was studied by X-ray diffraction to determine cell parameters and crystallite size. Decrease of the conductive properties of Co - nanotubes can be explained by inhomogeneity of the crystallites formed during synthesis, because the growth rate of nanostructures directly affects the size of the crystallites.

  7. Fabrication of Radar Array Antennas Using Large-Area, High-Resolution Lithography-on-Flex Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As the important role of NASA "missions to earth" has been clearly demonstrated in recent years, the need for radar antenna systems that have large fields of...

  8. K波段双圆极化波导阵列天线设计%Design of K-band dual-circularly-polarization waveguide array antennas

    Institute of Scientific and Technical Information of China (English)

    宋长宏; 吴群; 张文静

    2015-01-01

    The cross-polarizations and the polarization port isolation performance of conventional dual-polariza-tion waveguide slotted array antennas are poor,especially difficult to realize co-aperture dual-circularly-polariza-tion radiation.A novel dual-circularly-polarization waveguide array antenna at K-band is studied.The high-effi-ciency dual-polarized co-aperture radiation element,wide-band polarizer,low loss feed network are discussed, simulated and optimized by software.A prototype has been made and tested.The measured results show that waveguide array antennas proposed have the characteristics of high-efficiency,wide-band of axial ratio,and high-isolation.%传统的双极化波导缝隙天线阵每种极化方式交叉极化较差,极化端口隔离度不高,尤其实现共口径辐射难度较大。介绍了一种 K 波段双圆极化波导阵列天线设计方法,重点讨论了高效率共口径双极化辐射单元、宽带圆极化器、低损耗波导馈电网络。利用仿真软件进行了优化仿真分析,在此基础上研制了样件,对其电性能进行了测量。测试结果表明,此双圆极化波导阵列天线具有效率高、轴比带宽宽、隔离度高等特点。

  9. Experimental component Mode Synthesis Applied to the Solar Array Type Structure

    OpenAIRE

    Komatsu, Keiji; Sano, Masaaki; SANBONGI, Shigeo; Takashi Kai; TODA, Susumu; 小松, 敬治; 佐野, 政明; 三本木, 茂夫; 甲斐, 高志; 戸田, 勧

    1988-01-01

    A component mode synthesis technique based on experimentally determined modal parameters is presented in this paper. The test structure is a solar array type plate, which is divided into three parts, and four flexible connective parts. In the synthesis, the measured modes are approximated in polynomials to produce rotational degrees of freedom. The results sythesized are in good agreement with the test results obtained from a combined structure.

  10. 2D aperture synthesis for Lamb wave imaging using co-arrays

    Science.gov (United States)

    Ambrozinski, Lukasz; Stepinski, Tadeusz; Uhl, Tadeusz

    2014-03-01

    2D ultrasonic arrays in Lamb wave based SHM systems can operate in the phased array (PA) or synthetic focusing (SF) mode. In the real-time PA approach, multiple electronically delayed signals excite transmitting elements to form the desired wave-front, whereas receiving elements are used to sense scattered waves. Due to that, the PA mode requires multi channeled hardware and multiple excitations at numerous azimuths to scan the inspected region of interest. To the contrary, the SF mode, assumes a single element excitation of subsequent transmitters and off-line processing of the acquired data. In the simplest implementation of the SF technique, a single multiplexed input and output channels are required, which results in significant hardware simplification. Performance of a 2D imaging array depends on many parameters, such as, its topology, number of its transducers and their spacing in terms of wavelength as well as the type of weighting function (apodization). Moreover, it is possible to use sparse arrays, which means that not all array elements are used for transmitting and/ or receiving. In this paper the co-array concept is applied to facilitate the synthesis process of an array's aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum co-array is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual elements' locations in the sub-arrays used for imaging. The coarray framework will be presented here using two different array topologies, aID uniform linear array and a cross-shaped array that will result in a square coarray. The approach will be discussed in terms of array patterns and beam patterns of the resulting imaging systems. Both, theoretical and experimental results will be given.

  11. Certified dual-corrected radiation patterns of phased antenna arrays by offline–online order reduction of finite-element models

    International Nuclear Information System (INIS)

    This paper presents a fast numerical method for computing certified far-field patterns of phased antenna arrays over broad frequency bands as well as wide ranges of steering and look angles. The proposed scheme combines finite-element analysis, dual-corrected model-order reduction, and empirical interpolation. To assure the reliability of the results, improved a posteriori error bounds for the radiated power and directive gain are derived. Both the reduced-order model and the error-bounds algorithm feature offline–online decomposition. A real-world example is provided to demonstrate the efficiency and accuracy of the suggested approach

  12. The Noise Performance of a Multiple-Input-Port and Multiple-Output-Port Low-Noise Amplifier Connected to an Array of Coupled Antennas

    Directory of Open Access Journals (Sweden)

    Frédéric Broydé

    2011-01-01

    Full Text Available We address the noise characterization of a multiple-input-port and multiple-output-port (MIPMOP device receiving signals from an array of antennas. A definition of the noise figures and natural noise figures of a MIPMOP device is provided, and the resulting properties are detailed in the impedance and admittance representations. We compute the natural noise figures of a low-noise MIPMOP amplifier comprising a MIMO series-series feedback amplifier (MIMO-SSFA, designed for a wireless receiver front-end.

  13. Certified dual-corrected radiation patterns of phased antenna arrays by offline–online order reduction of finite-element models

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, A., E-mail: a.sommer@lte.uni-saarland.de; Farle, O., E-mail: o.farle@lte.uni-saarland.de; Dyczij-Edlinger, R., E-mail: edlinger@lte.uni-saarland.de

    2015-10-15

    This paper presents a fast numerical method for computing certified far-field patterns of phased antenna arrays over broad frequency bands as well as wide ranges of steering and look angles. The proposed scheme combines finite-element analysis, dual-corrected model-order reduction, and empirical interpolation. To assure the reliability of the results, improved a posteriori error bounds for the radiated power and directive gain are derived. Both the reduced-order model and the error-bounds algorithm feature offline–online decomposition. A real-world example is provided to demonstrate the efficiency and accuracy of the suggested approach.

  14. Integrated solar panel antennas

    OpenAIRE

    Vaccaro, S.; P. TORRES; Mosig, J. R.; Shah, Arvind; Zürcher,, J.-F.; A. K. Skrivervik; Gardiol, F.; de Maagt, P.; Gerlach, L.

    2008-01-01

    A new antenna which combines solar cells and printed patches is presented. The antenna is designed so as to accommodate the solar cells that provide power to an MMIC amplifier. A 2×4 array is presented, which operates at the frequency of 3.76 GHz and has a bandwidth of 16% and gain up to 30 dBi (active).

  15. Recent results from a continuous wave stepped frequency GPR system using a new ground-coupled multi-element antenna array

    Science.gov (United States)

    Linford, Neil; Linford, Paul; Payne, Andy

    2016-04-01

    The recent availability of multi-channel GPR instrumentation has allowed high-speed acquisition of densely sampled data sets over unprecedented areas of coverage. Such instrumentation has been of particular interest for the mapping of near-surface archaeological remains where the ability to collect GPR data at very close sample spacings (garden remains and a medieval farmstead to assess the response of the ground-coupled antenna to more challenging site conditions, particularly through water saturated soils. A full production DXG1820 version of the antenna became available for field work in 2015 offering optimisation of the individual element design to aid the recovery of weak return signals. Again, this has proved useful over sites where the presence of water saturated soils may have compromised the use of an air-coupled antenna array, or potentially restricted the depth of signal penetration. Collecting densely samples GPR data over very large areas has, however, also produced additional challenges regarding data processing, particularly for assessing acquisition quality in the field, and the interpretation of the resulting results. Some consideration of these aspects will also be covered in the presentation.

  16. Time-domain scattering properties of microstrip array antennas%微带阵列天线的时域散射特性

    Institute of Scientific and Technical Information of China (English)

    张雪芹; 王均宏; 李铮

    2011-01-01

    In this paper, the scattering characteristics of microstrip antenna arrays in time domain are analyzed using finitedifference time domain (FDTD) method. The distributions of scattering field components, Ea and Ea, are studied when the polarization and incidence directions of the incident pulse vary. The relationship of time domain waveforms and spectra of the scattering field with the microstrip antenna array structure is analyzed. The effect of ground plane on the scattering field of microstrip patch array is investigated using the field separating approach. It was found that the scattering field of microstrip antenna array with finite ground plane is mainly generated by the edge current on the ground plane. The resonance frequency of microstrip patch array is associated with the polarization direction of the incident pulse, hence,different polarization directions correspond to different spectra of the scattering field.%本文用时域有限差分方法(FDTD)研究了微带阵列天线的时域散射场,分析了入射脉冲极化方向不同以及入射方向不同时的散射场的分布情况;讨论了时域散射场的时域波形以及频谱与微带阵列天线结构的关系;用散射场分离算法讨论了地板对于微带贴片阵列散射场的影响.研究发现,有限大地板的微带阵列天线的散射场主要是由地板的边沿电流产生的,同时微带贴片阵列的谐振频率与入射脉冲的极化方向有关,因此不同的极化方向对应于不同的散射频谱.

  17. SKALA, a log-periodic array antenna for the SKA-low instrument: design, simulations, tests and system considerations

    CERN Document Server

    Acedo, E de Lera; Troop, N; Drought, N; Faulkner, A J

    2015-01-01

    The very demanding requirements of the SKA-low instrument call for a challenging antenna design capable of delivering excellence performance in radiation patterns, impedance matching, polarization purity, cost, longevity, etc. This paper is devoted to the development (design and test of first prototypes) of an active ultra-wideband antenna element for the low-frequency instrument of the SKA radio telescope. The antenna element and differential low noise amplifier described here were originally designed to cover the former SKA-low band (70-450MHz) but it is now aimed to cover the re-defined SKA-low band (50-350MHz) and furthermore the antenna is capable of performing up to 650MHz with the current design. The design is focused on maximum sensitivity in a wide field of view (+/- 45deg from zenith) and low cross-polarization ratios. Furthermore, the size and cost of the element has to be kept to a minimum as millions of these antennas will need to be deployed for the full SKA in very compact configurations. The p...

  18. SKALA, a log-periodic array antenna for the SKA-low instrument: design, simulations, tests and system considerations

    Science.gov (United States)

    de Lera Acedo, E.; Razavi-Ghods, N.; Troop, N.; Drought, N.; Faulkner, A. J.

    2015-10-01

    The very demanding requirements of the SKA-low instrument call for a challenging antenna design capable of delivering excellent performance in radiation patterns, impedance matching, polarization purity, cost, longevity, etc. This paper is devoted to the development (design and test of the first prototypes) of an active ultra-wideband antenna element for the low-frequency instrument of the SKA radio telescope. The antenna element and differential low noise amplifier described here were originally designed to cover the former SKA-low band (70-450 MHz) but it is now aimed to cover the re-defined SKA-low band (50-350 MHz) and furthermore the antenna is capable of performing up to 650 MHz with the current design. The design is focused on maximum sensitivity in a wide field of view (+/- 45° from zenith) and low cross-polarization ratios. Furthermore, the size and cost of the element has to be kept to a minimum as millions of these antennas will need to be deployed for the full SKA in very compact configurations. The primary focus of this paper is therefore to discuss various design implications for the SKA-low telescope.

  19. A New Method of Solving Kernels in Algebraic Decomposition for the Synthesis of Logic Cell Array

    Institute of Scientific and Technical Information of China (English)

    马光胜; 张忠伟; 等

    1995-01-01

    In this paper,an improvement has been made on the algorithm of solving the kernels of new functions which are generated after a common divisor appearing in the original functions is replaced by a new intermediate variable.And an efficient method based on kernel heritage is presented.This method has been successfully used in synthesis of LCA (Logic Cell Array).

  20. 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.