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Antennas and Propagation, IEEE Transactions on

Issue 1 • Date Jan. 2012

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Displaying Results 1 - 25 of 58
  • Table of contents

    Publication Year: 2012 , Page(s): C1 - 1
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  • IEEE Transactions on Antennas and Propagation publication information

    Publication Year: 2012 , Page(s): C2
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  • Maximum Gain of a Lossy Antenna

    Publication Year: 2012 , Page(s): 2 - 7
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB) |  | HTML iconHTML  

    An upper bound on the achievable gain of a lossy antenna is derived. This limit depends on the antenna size and a newly defined “loss merit factor,” which is shown to be a measure of the antenna material loss. The derived limit extends the well-known upper limit on the ratio of antenna directivity to its quality factor to the lossy antennas. Optimal antenna current distribution for the maximum gain is found, and the radiation pattern and antenna efficiency are also presented. View full abstract»

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  • Experimental Validation of Performance Limits and Design Guidelines for Small Antennas

    Publication Year: 2012 , Page(s): 8 - 19
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1280 KB) |  | HTML iconHTML  

    The theoretical limit for small antenna performance that was derived decades ago by Wheeler and Chu governs design tradeoffs for size, bandwidth, and efficiency. Theoretical guidelines have also been derived for other details of small antenna design such as permittivity, aspect ratio, and even the nature of the internal structure of the antenna. In this paper, we extract and analyze experimental performance data from a large body of published designs to establish several facts that have not previously been demonstrated: (1) The theoretical performance limit for size, bandwidth, and efficiency are validated by all available experimental evidence. (2) Although derived for electrically small antennas, the same theoretical limit is also generally a good design rule for antennas that are not electrically small. (3) The theoretical predictions for the performance due to design factors such as permittivity, aspect ratio, and the internal structure of the antenna are also supported by the experimental evidence. The designs that have the highest performance are those that involve the lowest permittivity, have an aspect ratio close to unity, and for which the fields fill the minimum size enclosing sphere with the greatest uniformity. This work thus validates the established theoretical design guidelines. View full abstract»

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  • Substrate Integrated Waveguide (SIW) Leaky-Wave Antenna With Transverse Slots

    Publication Year: 2012 , Page(s): 20 - 29
    Cited by:  Papers (30)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1491 KB) |  | HTML iconHTML  

    A novel slotted substrate integrated waveguide (SIW) leaky-wave antenna is proposed. This antenna works in the TE10 mode of the SIW. Leakage is obtained by introducing a periodic set of transverse slots on the top of the SIW, which interrupt the current flow on the top wall. It is seen that three modes (a leaky mode, a proper waveguide mode, and a surface-wave-like mode) can all propagate on this structure. The wavenumbers of the modes are calculated theoretically and are numerically evaluated by HFSS simulation. The leakage loss, dielectric loss, and conductor loss are also analyzed. A uniform slotted SIW leaky-wave antenna is designed that has good beam scanning from near broadside (though not exactly at broadside) to forward endfire. This type of SIW leaky-wave antenna has a wide impedance bandwidth and a narrow beam that scans with frequency. Measured results are consistent with the simulation and the theoretical analysis. View full abstract»

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  • Subwavelength Substrate-Integrated Fabry-Pérot Cavity Antennas Using Artificial Magnetic Conductor

    Publication Year: 2012 , Page(s): 30 - 35
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1247 KB) |  | HTML iconHTML  

    This paper presents the high-gain low-profile subwavelength substrate-integrated Fabry-Pérot (FP) cavity antennas with artificial magnetic conductor (AMC) sheets. A partially reflective planar AMC sheet and a ground plane are used as the two reflectors of the FP-type resonant cavity for an ultra-thin planar design. The cavity is fully filled with dielectric substrate for further reduction of thickness of the antenna and easy integration. A microstrip patch antenna is embedded into the cavity as a feed. As design examples, the antennas are designed to operate at 10 GHz with a fixed overall thickness of λ0/9 (where λ0 is the operating wavelength in free space) and an aperture of 2λ0 × 2λ0. The losses caused by both dielectric and conductors are analyzed, which are critical for a fully dielectric substrate antenna design. The via-walls surrounding the radiating aperture are introduced to improve radiation patterns and gain by suppressing the surface waves, which are another critical loss for a thin fully dielectric substrate antenna design. Measured results show that such dielectric-integrated subwavelength cavity antennas feature the high gain of 12.5 dBi, low profile, easy integration into circuit board, and mechanical robustness, which makes them suitable for low-cost mass production. View full abstract»

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  • A Reconfigurable Wideband and Multiband Antenna Using Dual-Patch Elements for Compact Wireless Devices

    Publication Year: 2012 , Page(s): 36 - 43
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1738 KB) |  | HTML iconHTML  

    A reconfigurable wideband and multiband C-Slot patch antenna with dual-patch elements is proposed and studied. It occupies a compact volume of 50 × 50 × 1.57 (3925 mm3), including the ground plane. The antenna can operate in two dual-band modes and a wideband mode from 5 to 7 GHz. Two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and the wideband modes. Two switches, implemented using PIN diodes, are placed on the connecting lines of a simple feed network to the patch elements. Dual-band modes are achieved by switching “ON” either one of the two patch elements, while the wideband mode with an impedance bandwidth of 33.52% is obtained by switching “ON” both patch elements. The frequencies in the dual-band modes can be independently controlled using positions and dimensions of the C-Slots without affecting the wideband mode. The advantage of the proposed antenna is that two dual-band operations and one wideband operation can be achieved using the same dimensions. This overcomes the need for increasing the surface area normally incurred when designing wideband patch antennas. Simulation results are validated experimentally through prototypes. The measured radiation patterns and peak gains show stable responses and are in good agreements. Coupling between the two patch elements plays a major role for achieving the wide bandwidth and the effects of mutual coupling between the patch elements are also studied. View full abstract»

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  • Frequency-Reconfigurable Monopole Antennas

    Publication Year: 2012 , Page(s): 44 - 50
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1903 KB) |  | HTML iconHTML  

    A novel coplanar-waveguide (CPW) bandpass filter using short-circuit slotlines and varactor diodes is introduced. This bandpass filter, when integrated with a CPW wideband antenna, produces frequency agility with a wideband mode and a continuous narrowband mode. The design of another CPW filter based on a square-ring resonator with switches is also shown and applied to a wideband antenna, making it reconfigurable. Both filters are based on controlling two stop bands far enough apart so that there is a passband between them. When the stop band frequencies are altered using switches or varactors, the passband is altered. Complete working and design principles along with simulated S-parameter results of the filters are presented. The simulated and measured reflection coefficients of the antennas incorporating the filters are also shown. Good monopole-like radiation characteristics are observed for both antennas. The filters are small in size and can be incorporated in any CPW antenna design to make it reconfigurable. The benefits of the novel varactor filter antenna over the switch filter antenna are also described. View full abstract»

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  • Low Profile Fully Planar Folded Dipole Antenna on a High Impedance Surface

    Publication Year: 2012 , Page(s): 51 - 62
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2400 KB) |  | HTML iconHTML  

    A fully planar antenna design incorporating a high impedance surface (HIS) is presented. The HIS is composed by a periodic array of subwavelength dogbone-shaped conductors printed on top of a thin dielectric substrate and backed by a metallic ground plane. First, the characteristics of a dipole over PEC or PMC layers, a dielectric slab, and the HIS are compared and studied in detail, highlighting the advantages provided by the use of the HIS. Then, the design of a low profile folded dipole antenna working at 5.5 GHz on top of the HIS is described. The surface provides close to 6% antenna impedance bandwidth and increased gain up to 7 dBi, while shielding the lower half space from radiation. The antenna structure comprises three metal layers without any vias between them, and its overall thickness is 0.059λ0. The dipole is fed by a balanced twin lead line through a balun transformer integrated in the same antenna layer. A prototype has been built and measurements confirming simulation results are provided. View full abstract»

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  • Crumpling of PIFA Textile Antenna

    Publication Year: 2012 , Page(s): 63 - 70
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1834 KB) |  | HTML iconHTML  

    The performance of a PIFA textile antenna under different crumpling conditions is presented. The PIFA was designed for integration into clothing and other textile applications and the bending and crumpling conditions studied are typical of those found under normal use conditions both on and off body. Input impedance, efficiency and radiation patterns are investigated based on numerical and experimental methods at 2.4 GHz. Crumpling can have a serious effect on the resonant frequency, bandwidth and radiation from textile antennas. View full abstract»

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  • Higher Order Mode Excitation for High-Gain Broadside Radiation From Cylindrical Dielectric Resonator Antennas

    Publication Year: 2012 , Page(s): 71 - 77
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1494 KB) |  | HTML iconHTML  

    A resonant mode (HEM12δ), other than those ( HEM11δ and TM01δ) conventionally excited and used in a cylindrical dielectric resonator antenna (CDRA) has been examined with a view for using it as another radiating mode with broadside radiation patterns. Excitation of the mode, being the most challenging aspect, has been discussed and resolved by employing an innovative technique. The proposed concept has been successfully verified and experimentally demonstrated for the first time. More than 8-dBi peak gain with excellent broadside radiation has been obtained from a prototype shaped from a commercially available low-loss dielectric material with relative permittivity 10. View full abstract»

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  • On the Characteristics of the Highly Directive Resonant Cavity Antenna Having Metal Strip Grating Superstrate

    Publication Year: 2012 , Page(s): 78 - 91
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4390 KB) |  | HTML iconHTML  

    Various resonant cavity antennas (RCAs) having different metal strip gratings (MSGs) as their superstrates are studied in terms of their directivity and scanning properties using transverse equivalent network (TEN) model in conjunction with the periodic method of moments (MoM). It is shown that radiation patterns in E- and H-planes coincide over a wide angle range in RCAs when their MSG superstrates are free-standing and highly reflective, as reported in the previous literature. However, using less reflective MSG or employing dielectric support in the MSG superstrate degrades the equality of E- and H-plane radiation patterns. Moreover, as the scan angle increases, radiation patterns in E- and H-planes become noticeably different. It is elucidated that this is due to the angular dependence of the reflection coefficient phase of the MSG superstrates. A comparative study is also performed on a few different RCAs based on both simulation and measurement results. It is illustrated that in practice when the excitation source of the RCA is a probe-fed microstrip antenna and the RCA is finite in size, cross-polarization increases considerably as opposed to the RCAs having ideal sources and, infinite ground plane and MSG superstrate in the transverse direction. View full abstract»

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  • Nature of Cross-Polarized Radiations from Probe-Fed Circular Microstrip Antennas and Their Suppression Using Different Geometries of Defected Ground Structure (DGS)

    Publication Year: 2012 , Page(s): 92 - 101
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2540 KB) |  | HTML iconHTML  

    Experiments with probe-fed circular patches using conventional and defected ground planes flashed some interesting features relating to cross-polarized (XP) electric fields and associated radiations before the present authors. Those led to a series of new investigations for understanding the nature of XP fields and to deal with them using defected ground structure (DGS) for improved XP performance. In the first phase of investigation, the XP radiations of a probe-fed circular patch with conventional ground plane have been critically studied as a function of the radial probe location. Remarkably significant effect is experimentally demonstrated. New information about orthogonal resonant fields and its importance in designing an antenna is provided. In the second phase of investigation, limitations of dot-shaped DGS in reducing XP level are experimentally studied. As its improved variants, two new DGS geometries such as annular ring and circular arcs have been explored. The arc-DGS appears to be highly efficient in terms of suppressing XP fields. Suppression by 10-12 dB has been experimentally demonstrated. Each design has been experimented in both C- and X-bands to earn confidence on the measured data. View full abstract»

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  • Single, Dual and Tri-Band-Notched Ultrawideband (UWB) Antennas Using Capacitively Loaded Loop (CLL) Resonators

    Publication Year: 2012 , Page(s): 102 - 109
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1741 KB) |  | HTML iconHTML  

    Two compact, printed, ultrawideband (UWB) monopole antennas with tri-band notched characteristics are reported. The notched filters are achieved by introducing printed, electrically small, capacitively-loaded loop (CLL) resonators. The directly driven elements consist of printed top-loaded CLL-based monopoles and 50 Ω microstrip feed lines. By adding three CLL elements close to the feed line, band-notch properties in the WiMAX (3.3-3.6GHz), lower WLAN (5.15-5.35GHz) and higher WLAN (5.725-5.825GHz) bands are achieved. Each antenna system is contained on a 27×34mm2 sheet of Rogers Duroid 5880 substrate. One is designed with three additional CLL elements; the other is achieved with only two. Comparisons between the simulation and measurement results show that these UWB antennas have broadband matched impedance values and stable radiation patterns for all radiating frequencies. View full abstract»

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  • Leaky Wave Enhanced Feeds for Multibeam Reflectors to be Used for Telecom Satellite Based Links

    Publication Year: 2012 , Page(s): 110 - 120
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2036 KB) |  | HTML iconHTML  

    The use of dielectric super-layers for shaping the radiation pattern of focal plane feeds of a multibeam reflector system is discussed. Using the super-layers, it is possible to reduce the spillover from the reflectors without increasing the dimension of each aperture. The effect has been demonstrated using a realistic array configuration. The experimental demonstration is obtained with configurations which are typical for satellite based multi beam telecommunication links. Thanks to the adoption of a × 4 reuse scheme, based on frequency and polarization orthogonal channels, the measured edge of coverage directivity has improved, with respect to a standard technology case, by 2 dB over an operational bandwidth of about 2%. View full abstract»

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  • 94 GHz Substrate Integrated Monopulse Antenna Array

    Publication Year: 2012 , Page(s): 121 - 129
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2181 KB) |  | HTML iconHTML  

    A planar W-band monopulse antenna array is designed based on the substrate integrated waveguide (SIW) technology. The sum-difference comparator, 16-way divider and 32 × 32 slot array antenna are all integrated on a single dielectric substrate in the compact layout through the low-cost PCB process. Such a substrate integrated monopulse array is able to operate over 93 ~ 96 GHz with narrow-beam and high-gain. The maximal gain is measured to be 25.8 dBi, while the maximal null-depth is measured to be - 43.7 dB. This SIW monopulse antenna not only has advantages of low-cost, light, easy-fabrication, etc., but also has good performance validated by measurements. It presents an excellent candidate for W-band directional-finding systems. View full abstract»

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  • The Planar Ultrawideband Modular Antenna (PUMA) Array

    Publication Year: 2012 , Page(s): 130 - 140
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2250 KB) |  | HTML iconHTML  

    A fully planar ultrawideband phased array with wide scan and low cross-polarization performance is introduced. The array is based on Munk's implementation of the current sheet concept, but it employs a novel feeding scheme for the tightly coupled horizontal dipoles that enables simple PCB fabrication. This feeding eliminates the need for “cable organizers” and external baluns, and when combined with dual-offset dual-polarized lattice arrangements the array can be implemented in a modular, tile-based fashion. Simple physical explanations and circuit models are derived to explain the array's operation and guide the design process. The theory and insights are subsequently used to design an exemplary dual-polarized infinite array with 5:1 bandwidth and VSWR <; 2.1 at broadside, and cross-polarization ≈ -15 dB out to θ = 45° in the D- plane. View full abstract»

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  • A Two-Channel Time Modulated Linear Array With Adaptive Beamforming

    Publication Year: 2012 , Page(s): 141 - 147
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1706 KB) |  | HTML iconHTML  

    A Time modulated linear array (TMLA) can be configured to perform many of the functions of phased array antennas but at much lower cost as they do not require phase shifters. However, conventional time modulated linear arrays which are configured for beam steering based on a single output channel topology. Such a topology is inefficient in terms of time utilization of the array elements. In this contribution we have proposed a multiple output channels time modulated linear array which exploits the time redundancy of conventional systems. The concept is introduced by considering conventional harmonic beam steering and then extending the problem to two-channel adaptive beamforming. View full abstract»

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  • Aperiodic Array Layout Optimization by the Constraint Relaxation Approach

    Publication Year: 2012 , Page(s): 148 - 163
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3167 KB) |  | HTML iconHTML  

    An optimization procedure for the layout assessment of electrically large but finite planar arrays is presented. The synthesis takes into account the desired directivity pattern that is prescribed employing bound constraints. Moreover, the size of the radiators is taken into account, which results in a hard nonoverlapping, between the elements, constraint. The latter should not be violated if we want the attained solution not only to obey the far-field mask, but also to be physically realizable. As stated, the optimization problem is twofold. An antenna design is associated with a packing problem. In order to take the constraints on the layout into account and solve the whole problem, we propose the constraint relaxation approach, which is equipped with a packing algorithm. Our study is applied to various initial geometries, and the resulting arrays appear to comply with the desired pattern and the nonoverlapping constraint. Several examples for different cases including symmetric arrays and a study on maximally sparse arrays are presented, which show the applicability and merit of the method. View full abstract»

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  • Time Reversal Based Broadband Synthesis Method for Arbitrarily Structured Beam-Steering Arrays

    Publication Year: 2012 , Page(s): 164 - 173
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2478 KB) |  | HTML iconHTML  

    We propose a novel broadband beam pattern synthesis method to synthesize arbitrarily structured beam-steering arrays by utilizing time reversal technique. Unlike conventional frequency-domain array synthesis methods, this method achieves array excitation by taking the Fourier Transform of the time reversed version of the transient signals received by antenna elements. Using this method, designers can determine the array excitation over a wide frequency range at once by a single run of time reversal experiment, instead of performing time-consuming multi-objective optimizations of beam pattern cost-functions at each frequency. Furthermore, it does not require explicit measurements of element mutual coupling and platform scattering effects since the time reversal signals have implicitly taken into account those effects. The proposed method is theoretically analyzed with the antenna reciprocity and numerically validated with three dipole arrays of different configurations. The results show that this new method is capable of realizing accurate beam steering over a wide frequency band if the desired steering angle is located in the feasible angular scope of beam scan. The beam patterns with accurate beam steering are successfully achieved over a bandwidth of more than 1.5 GHz for three different dipole arrays, i.e., a typical linear dipole array, a grounded circular dipole array, and a dome-shaped dipole array. View full abstract»

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  • A Generalized Hybrid Approach for the Synthesis of Uniform Amplitude Pencil Beam Ring-Arrays

    Publication Year: 2012 , Page(s): 174 - 183
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1598 KB) |  | HTML iconHTML  

    A generalized hybrid algorithm for the synthesis of uniform amplitude ring-arrays is introduced. The method exploits the analytical properties of the field radiated by a circular array in order to get advantages from the use of convex programming techniques. The method, aimed to the synthesis of circularly symmetric patterns, is very flexible and allows the use of different kind of feeds as well as stepped excitations. The synthesis procedure is demonstrated in the case of high-directivity pencil beam patterns. View full abstract»

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  • Polarimetry With Phased Array Antennas: Theoretical Framework and Definitions

    Publication Year: 2012 , Page(s): 184 - 196
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1948 KB) |  | HTML iconHTML  

    For phased array receivers, the accuracy with which the polarization state of a received signal can be measured depends on the antenna configuration, array calibration process, and beamforming algorithms. A signal and noise model for a dual-polarized array is developed and related to standard polarimetric antenna figures of merit, and the ideal polarimetrically calibrated, maximum-sensitivity beamforming solution for a dual-polarized phased array feed is derived. A practical polarimetric beamformer solution that does not require exact knowledge of the array polarimetric response is shown to be equivalent to the optimal solution in the sense that when the practical beamformers are calibrated, the optimal solution is obtained. To provide a rough initial polarimetric calibration for the practical beamformer solution, an approximate single-source polarimetric calibration method is developed. The modeled instrumental polarization error for a dipole phased array feed with the practical beamformer solution and single-source polarimetric calibration was -10 dB or lower over the array field of view for elements with alignments perturbed by random rotations with 5 degree standard deviation. View full abstract»

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  • An Amplifying Reconfigurable Reflectarray Antenna

    Publication Year: 2012 , Page(s): 197 - 205
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1577 KB) |  | HTML iconHTML  

    Electronically tunable reflectarrays and amplifying reflectarrays have attracted considerable research in recent years, however, little work has been done to combine these two features simultaneously in a single design. This paper focuses on the design of such a reflectarray, which can be used as a high gain, reconfigurable transmitting antenna for communication links. The reflectarray element is an aperture-coupled microstrip patch that accepts a linearly polarized wave, phase shifts and amplifies the guided-waves in the transmission lines, and then re-radiates an orthogonally-polarized wave. First, the element design, modelling, stability analysis and experimental results are presented. Then a 48 element reflectarray prototype operating at 5.7 GHz is described and its two dimensional beam steering capability and amplifying nature are successfully demonstrated and verified. View full abstract»

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  • Design of Retrodirective Antenna Arrays for Short-Range Wireless Power Transmission

    Publication Year: 2012 , Page(s): 206 - 211
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (818 KB) |  | HTML iconHTML  

    Application of retrodirective antenna arrays in wireless power transmission is proposed in this paper. The time reversal or phase conjugate theory and design considerations of the array factors are examined in GHz regime and meter range. The wireless power transmission efficiency is analyzed in the 2-D case with full-wave electromagnetic (EM) solution and validated by analytical array theory. The design factors of array size, array spacing, element size, and specific choice of the industrial, scientific and medical (ISM) band frequency are investigated to optimize the transmission focus. Design guidelines are provided for those factors and the impact of manufacturing variability is discussed. The proposed approach can also be extended to wireless power transfer with active retrodirective rectenna array and passive RFID systems. View full abstract»

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  • Anisotropic Impedance Surfaces for Linear to Circular Polarization Conversion

    Publication Year: 2012 , Page(s): 212 - 219
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (900 KB) |  | HTML iconHTML  

    Anisotropic impedance surfaces are employed as low-profile and broadband reflectors that convert orthogonal linear to right- and left-handed circular polarization respectively. By virtue of anisotropy, it is possible to independently control the reflection characteristics of two orthogonal linearly polarized incident plane waves and therefore achieve linear to circular polarization conversion. Equivalent circuits for anisotropic impedance surfaces with arbitrarily shaped elements are employed to demonstrate the operating principle and a design procedure is proposed. The proposed design procedure is demonstrated by means of an example involving a dipole array. A prototype is designed and its performance characteristics are evaluated. The 3-dB relative axial ratio bandwidth exceeds 60%, while low loss and angular stability are also reported. Numerical and experimental results on a fabricated prototype are presented to validate the synthesis and the performance. View full abstract»

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IEEE Transactions on Antennas and Propagation includes theoretical and experimental advances in antennas.

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Editor-in-Chief                                                 Kwok W. Leung