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Antennas and Propagation, IEEE Transactions on

Issue 2  Part 1 • Date Feb. 2006

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  • Table of contents

    Page(s): c1 - 313
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  • IEEE Transactions on Antennas and Propagation publication information

    Page(s): c2
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  • Enhancing UHF antenna functionality through dielectric inclusions and texturization

    Page(s): 317 - 329
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    Dielectrics are used in antenna design to support the printed structure and to also reduce antenna resonance and size. However, to our knowledge, dielectric volumes have not been used in the design process (by modifying or texturizing the dielectric) to possibly alter the overall performance and behavior of the antenna. In this paper, we begin with a given metallic geometry and show how changes in dielectric loading (position and permittivity values) can be used to produce a variety of antenna configurations having broadband and multi-band characteristics while still pursuing size reduction. More specifically, using a 15 cm×15 cm×6 cm antenna geometry, we show various designs giving resonant frequencies down to 350 MHz (0.175λ0 linear dimension) and having bandwidths that can reach as high as 23.5% at 520 MHz (0.261λ0 linear dimension). Also shown are designs with dual band characteristics. An example broadband design is fabricated and measured. View full abstract»

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  • Single- and dual-band multimode hard horn antennas with partly corrugated walls

    Page(s): 330 - 339
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    We introduce a partly corrugated hard horn, consisting of a smooth-walled horn with an attached longitudinally corrugated outer section. This alleviates the problems with the manufacturing when the longitudinal corrugations extend into the throat of the horn. The transition between the inner smooth walled part and the outer corrugated part is abrupt. This is used and controlled to design better and shorter single-band horns than otherwise possible. Furthermore, it enables the design of dual-band horns with low cross-polarization and high gain, for multifunction use at Ka-band with transmit and receive frequencies in the same antenna. Measurements on a model of such a dual-band horn are presented and discussed. View full abstract»

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  • Dual-band low-profile corrugated feeder antenna

    Page(s): 340 - 350
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    A dual-operating-band planar horn antenna having very low profile is presented in this paper. By opening a subwavelength aperture into a corrugated conducting plate, good return losses and a narrow radiated beam in each of the two desired operating frequency bands can be measured. This behavior is very similar to that observed in optical wavelengths where enhanced transmission was measured through apertures etched in metallic corrugated plates. Here, the double-corrugated structure has been scaled into the microwave frequency range and the excitation has been done by a conventional closed metallic waveguide placed in the rear part of the structure. In this way, a new concept of a very low profile feeder is proposed with potential wireless applications. View full abstract»

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  • Effect of dielectric permittivity on infinite arrays of single-polarized Vivaldi antennas

    Page(s): 351 - 358
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    The effect of dielectric substrate on the performance of infinite arrays of single-polarized Vivaldi antennas is studied by computing the input impedance of an antenna in an array environment by using full wave method of moments techniques. It is found that dielectric permittivity plays an important role in the wideband performance of such arrays, and comparison with dielectric-free cases for similar geometries is also included to bring out the impact of the substrate. In particular, increasing dielectric permittivity improves the bandwidth considerably (bandwidth up to 10:1 is predicted). The parametric variation due to permittivity is presented in detail, and optimization involving other design parameters is discussed. Results from a parallel plate waveguide simulator technique employed to assess and compare the array performance of Vivaldi with different dielectric permittivities qualitatively support the predicted effect of dielectric substrate. View full abstract»

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  • A multiband, compact, and full-duplex beam scanning antenna transceiver system operating from 10 to 35 GHz

    Page(s): 359 - 367
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    This paper presents a compact phased-array antenna transceiver system that can operate over a wide bandwidth from 10 to 35 GHz with the abilities of beam scanning and full-duplex communication. The system consists of ultrawide-band Vivaldi antennas, a multiline PET-based phase shifter, a six-channel microstrip multiplexer, and monolithic microwave integrated circuit (MMIC) amplifiers. The multiplexer routes 10, 19, and 32 GHz signals to the transmit path and 12, 21, and 35 GHz signals to the receive path. The multiplexer shows insertion loss between 2.2 and 3.4 dB for all six channels and together with wide-band MMIC amplifiers plays an important role to build a compact, multifrequency, and full-duplex transceiver system. The system should have many applications in multiband satellite communication systems and radar systems. View full abstract»

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  • The eleven antenna: a compact low-profile decade bandwidth dual polarized feed for reflector antennas

    Page(s): 368 - 375
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    A novel dual polarized ultrawide-band (UWB) feed with a decade bandwidth is presented for use in both single and dual reflector antennas. The feed has nearly constant beam width and 11 dBi directivity over at least a decade bandwidth. The feed gives an aperture efficiency of the reflector of 66% or better over a decade bandwidth when the subtended angle toward the sub or main reflector is about 53°, and an overall efficiency better than 47% including mismatch. The return loss is better than 5 dB over a decade bandwidth. The calculated results have been verified with measurements on a linearly polarized lab model. The feed has no balun as it is intended to be integrated with an active 180° balun and receiver. The feed is referred to as the Eleven antenna because its basic configuration is two parallel dipoles 0.5 wavelengths apart and because it can be used over more than a decade bandwidth with 11 dBi directivity. We also believe that 11 dB return loss is achievable in the near future. View full abstract»

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  • The design of shared aperture antennas consisting of differently sized elements

    Page(s): 376 - 383
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    A consistent strategy for the design of finite array antennas consisting of differently sized radiating elements is discussed. In view of increasing the total bandwidth of the antenna system, while maintaining a low mutual coupling between the elementary radiators, sparse subarrays, operating at adjacent frequency ranges, are interleaved on a common (shared) aperture. The sparse architectures are designed using a combinatorial method that ensures an acceptable behavior in the side-lobes region in conjunction with a narrow beamwidth. The effect of the mutual coupling between identical and differently sized elements is accurately evaluated and is accounted for in predicting the performance of each individual radiator. The concept is illustrated by designing a shared aperture antenna consisting of two interwoven subarrays that jointly cover a fractional bandwidth of 14% in the X-band. Cavity-backed, stacked-patches antennas with coaxial feeding are used as elementary radiators. View full abstract»

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  • Integrated planar multiband antennas for personal communication handsets

    Page(s): 384 - 391
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    The advent of new, multistandard mobile phone devices is an important challenge for antenna designers, as they have to implement integrated antennas with multiband operation within a volume that is rapidly shrinking. In the paper, research results concerning the input return loss, radiation characteristics and efficiency of novel internal, planar, multiband patch antennas are presented. View full abstract»

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  • Optimized design of a multifunction/multiband antenna for automotive rescue systems

    Page(s): 392 - 400
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    The development of efficient automotive accident management systems requires the design of complex multifunction antennas enabling different wireless services (e.g., localization, voice and data communications, emergency calls, etc.). Starting from different specifications (electrical, mechanical, and aerodynamic), the design of a multifunction antenna must consider, in addition to the usual antenna design requirements, also interference phenomena arising from the integration of different classes of antennas in a compact device. In this framework, the paper describes a methodology based on a stochastic multiphases optimization approach for the design of an integrated multifunction/multiband antenna system. Moreover, for an exhaustive assessment, the results of an experimental validation performed on a prototype of the multifunction antenna system are shown and discussed. View full abstract»

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  • A varactor-tuned dual-band slot antenna

    Page(s): 401 - 408
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    A new technique for designing dual-band reconfigurable slot antennas is introduced. The technique is based on loading a slot antenna with a lumped capacitor (or varactor) at a certain location along the slot. Given a fixed capacitor location along the slot, decreasing the capacitance results in increasing the first and second resonant frequencies of the slot antenna. However, the changes in the resonant frequencies are significantly different for the first and second resonances and, hence, a dual-band antenna with considerable frequency ratio tuning range can be obtained. Based on this technique, an electronically tunable dual-band antenna with a frequency ratio in the range of 1.2-1.65 is designed and fabricated using a single varactor with a capacitance range of 0.5-2.2 pF. The antenna has similar radiation patterns with low cross-polarization levels at both bands and across the entire tunable frequency range. View full abstract»

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  • Dual-band reconfigurable antenna with a very wide tunability range

    Page(s): 409 - 416
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    A new technique for designing dual-band reconfigurable slot antennas is presented. Dual-frequency operation is achieved by loading a slot antenna with two lumped variable capacitors (varactors) placed in proper locations along the slot. Loading the slot antenna with lumped capacitors shifts down the resonant frequencies of the first and second resonances of the antenna. However, these frequency shifts depend not only on the values of the capacitors, but also on their locations along the slot antenna. Here, it is shown that by choosing the locations of the varactors appropriately, it is possible to obtain a dual-band antenna whose first and second resonant frequencies can be controlled individually. In other words, the frequency of either the first or the second band can be fixed, while the other one is electronically tuned. Using such a design, an electronically tunable dual-band antenna is designed and fabricated using two identical varactors having a capacitance range of 0.5-2.25 pF. The antenna is shown to have a frequency ratio (fR=f2/f1) ranging from 1.3 to 2.67. An important feature of this antenna is its consistent radiation pattern, polarization, and polarization purity at both bands and across its entire tunable frequency range. View full abstract»

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  • A tunable electrically small antenna for ground wave transmission

    Page(s): 417 - 421
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    A tunable, electrically small, wire antenna is developed for HF/VHF ground wave transmission. A variable capacitor is serially connected to tune the resonant frequency of the antenna. The optimal position for the placement of the capacitor is evaluated by numerical simulation. The tuning range and sensitivity are also investigated. A prototype antenna is built and tested, and the measured tuning performance is compared to the simulation results. Transmission loss tests are carried out in several nonline-of-sight environments. The measured transmission loss of the tunable small antenna is found to be within 1 to 2 dB of that of a commercial whip across the tested frequency range. View full abstract»

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  • Design, fabrication, and measurements of an RF-MEMS-based self-similar reconfigurable antenna

    Page(s): 422 - 432
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    Reconfigurability in an antenna system is a desired characteristic that has been the focus of much research in recent years. In this work, ohmic contact cantilever RF-MEMS switches are integrated with self-similar planar antennas to provide a reconfigurable antenna system that radiates similar patterns over a wide range of frequencies. The different issues encountered during the integration of the MEMS switches and the overall system design procedure are described herein. The final model radiates at three widely separated frequencies with very similar radiation patterns. The proposed concept can be extended to reconfigurable linear antenna arrays or to more complex antenna structures with large improvements in antenna performance. View full abstract»

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  • Design of a wide-band L-probe patch antenna for pattern reconfiguration or diversity applications

    Page(s): 433 - 438
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    By supporting an L-probe coupled circular patch antenna with four metallic posts at appropriate locations, it is demonstrated that the conical and the broadside modes which are excited separately by two different sets of L-shaped probes, can be operated at the same frequency range. For a tested antenna operated at 1.85 GHz, the bandwidth (SWR<2) achieved is 24%, and the isolation between the two input ports is 28 dB. The gains of the conical and broadside modes are 4 and 8.5 dBi, respectively. With suitable switching feed networks, the antenna can be reconfigurable in radiation pattern. The antenna can also be used as a pattern diversity antenna for modern mobile communications. View full abstract»

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  • Pattern and frequency reconfigurable annular slot antenna using PIN diodes

    Page(s): 439 - 448
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    This paper presents the use of pin diodes to reconfigure the impedance match and modify the radiation pattern of an annular slot antenna (ASA). The planar antenna is fabricated on one side of a Duroid substrate and the microstrip feeding line with the matching network is fabricated on the opposite side of the board. The central frequency is 5.8 GHz and, by reconfiguring the matching circuit, the antenna was also designed to operate at 5.2 and 6.4 GHz. Pin diodes are also used to short the ASA in preselected positions along the circumference, thereby changing the direction of the in the plane defined by the circular slot changes. As a proof of concept, two pin diodes are placed 45° on both sides of the feeding line along the ASA and the direction of the is shown to align with the direction defined by the circular slot center and the diode. Consequently, a design that is reconfigurable in both frequency and radiation pattern is accomplished. Return loss and radiation pattern measurements and simulations are presented, which are in very good agreement. View full abstract»

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  • Frequency and beam reconfigurable antenna using photoconducting switches

    Page(s): 449 - 454
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    A design for an optically reconfigurable printed dipole antenna is presented. A wideband coplanar waveguide (CPW) to coplanar stripline (CPS) transition is used to feed the balanced printed dipole. Two silicon photo switches are placed on small gaps in both dipole arms equidistant from the centre feed. Light from two infrared laser diodes channelled through fiber optic cables is applied to the switches. With the gaps in the dipole bridged, the antenna resonates at a lower frequency. Measured return loss results that compare well to the simulated values are also presented, showing a frequency shift of nearly 40%. The change in bore-sight gain along with radiation patterns are also presented. Activating each switch individually results in a near 50° shift in beam s. View full abstract»

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  • Reconfigurable scan-beam single-arm spiral antenna integrated with RF-MEMS switches

    Page(s): 455 - 463
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    A fully integrated solution providing scan-beam capability with a single antenna is presented in this paper for the first time. The proposed system includes a reconfigurable rectangular spiral antenna with a set of micro electro mechanical system (MEMS) switches, which are monolithically integrated and packaged onto the same substrate. The system is based on a single-arm rectangular spiral antenna, capable of changing its radiation pattern using radio frequency-MEMS (RF-MEMS) switches. The rectangular spiral and RF-MEMS switches are monolithically integrated on a conventional microwave substrate printed circuit board (εr=3.27 and tanδ=0.004) and quartz substrate (εr=3.78 and tanδ=0.0002). The spiral is made out of multiple lines, which are interconnected by RF-MEMS switches strategically located along the spiral. On activating these switches, the spiral overall arm length is changed and consequently its radiation beam direction is changed. The two proposed antennas radiate right hand circular polarization (RHCP) and left hand circular polarization (LHCP) for printed circuit board and quartz substrate respectively. The gain of the two antennas varies between 3∼6 dBi. They both satisfy the 3-dB axial ratio criterion at their operating frequency band, i.e., at 10 GHz and 6 GHz for the printed circuit board and the quartz substrate respectively. To the best of our knowledge, this is the first truly reconfigurable printed antenna design using MEMS devices as active elements integrated in the same low loss substrate. The excellent performance of the proposed system emphasizes the importance of being able to integrate MEMS switches into the same low loss substrate for antenna applications. This technology pioneers the design of arbitrarily shaped reconfigurable antennas including the design of reconfigurable antenna arrays. View full abstract»

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  • Integration of packaged RF MEMS switches with radiation pattern reconfigurable square spiral microstrip antennas

    Page(s): 464 - 469
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (760 KB) |  | HTML iconHTML  

    This work describes the integration of commercially available packaged radio frequency microelectromechanical system (RF MEMS) switches with radiation pattern reconfigurable microstrip antennas. Most applications of RF MEMS switches consider the switches as only circuit elements. In contrast, the implementation of packaged switches in this particular antenna must address not only the simple open/closed behavior of the switches but also their impact on the radiation characteristics of the reconfigurable antenna. Here, two Radant MEMS single-pole single throw (SPST) SPST-RMSW100 (packaged RF MEMS) switches are used to reconfigure the radiation patterns of a resonant square spiral microstrip antenna between endfire and broadside over a common impedance bandwidth. Switch insertion, matching network design, and other issues are addressed. Results for both simulated and measured antennas, as well as recommendations for future work in this area, are provided. View full abstract»

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  • Reconfigurable RF impedance tuner for match control in broadband wireless devices

    Page(s): 470 - 478
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    This paper presents the design of a broadband RF impedance tuner that is part of a dynamically reconfigurable automatic match control (AMC) circuit that can be used for a wide variety of wireless devices and intelligent RF front ends. The impedance tuner can be used at the input of wireless devices in order to provide a significantly broader bandwidth or to reconfigure the impedance match spectrum. The tuner uses a microstrip loaded-line circuit topology with multiple stubs that each have a varactor diode located at the end. The results show that the tuner can achieve a broadband impedance match for a wide variety of loads that are either purely resistive or that have a large reactance as well. View full abstract»

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  • Six-state reconfigurable filter structure for antenna based systems

    Page(s): 479 - 483
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    This paper demonstrates a six-state reconfigurable band-pass filter intended to add frequency tunability to antenna systems. The present topology produces filter responses with center frequencies of f0= 9, 10, and 11 GHz and achieves independent bandwidth control with an average tunable passband ratio of 1.73:1 between the wideband configurations ranging from 13.4% and 14.7% and the narrowband configurations ranging from 7.7% and 8.5%. PIN diodes are implemented as switching elements and the distinct states are discretely accomplished by the connection and isolation of strategically placed transmission line sections. The insertion loss of the filter ranges between 1.74 and 1.92 dB. The circuit produces no significant signal distortion resulting in third-order intermodulation intercept points (IIP3) greater than 48 dBm for tones separated by 1 MHz around the center frequencies. View full abstract»

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  • Novel application of the hollow dielectric resonator antenna as a packaging cover

    Page(s): 484 - 487
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    The dual functions of the rectangular hollow dielectric resonator antenna (DRA) as an antenna and a packaging cover are investigated. The design methodology is discussed, and the return loss, impedance, and radiation patterns for the fundamental mode are presented at 2.4 GHz, a popular frequency band for the WLAN and wireless communications. A low-noise amplifier is integrated successfully into the embedded cavity to form an active DRA, and the amplified radiation patterns are analyzed. The proposed DRA provides a possible solution to the size minimization of transceivers. View full abstract»

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    Page(s): 488
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Aims & Scope

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

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Editor-in-Chief                                                 Kwok W. Leung