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- 摘要
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Pattern Reconfigurable Wideband Loop Antenna for Thorax Imaging
摘要： A unidirectional loop antenna that can achieve wideband pattern re-configurability from -40 to +40 degrees in azimuth plane is presented. The antenna is designed to fulfill the multi-slice (level) scanning requirements of electromagnetic imaging (EMI) systems for thorax imaging. To overcome the need for positioning of several antenna-arrays, and hence eliminate the mutual coupling related complications, a square-loop antenna with reconfigurable pattern is designed. To create a unidirectional radiation, the loop is loaded with capacitive gaps, which convert its radiation mechanism to that of two virtual dipole arrays with quadrature phase excitation. By utilizing this feature, the location of the gaps are varied on the loop's structure to form virtual dipole arrays in different directions, thus rotating the radiation pattern without physically moving the structure of the antenna. As a proof of concept, six gaps were created on the loop and each gap is loaded with a PIN diode to electronically switch between the positions of the designed gaps, thus enabling changing the radiation direction. The proposed antenna can achieve a compact size of 0.32λ×0.32λ×0.002λ (λ is the wavelength of the lowest resonance of the antenna) and a wide fractional bandwidth of 32% at 0.8-1.15 GHz, with a peak gain and front-to-back-ratio of 2.1 dBi and 8 dB, respectively. The antenna is successfully tested on a thorax imaging platform to detect small volume of water (5 mL) inside lungs as an emulation of early pulmonary edema.
关键词： unidirectional antenna,virtual dipole array,pattern reconfigurable antenna,loop antenna,Electromagnetic imaging,wideband antenna
更新于2025-09-23 15:23:52
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Polarization Reconfigurable Corner Truncated Square Microstrip Array Antenna
摘要： In this paper, a simple 2 × 2 polarization reconfigurable planar microstrip array antenna is presented. It is based on electrical switching technology using PIN diodes. Each element of the array is excited with the aid of the corporate feed technique. Each element of the proposed structure consists of a corner truncated square patch connected to parasitic triangular conductors by means of PIN diodes. The array element is configured to facilitate linear polarization (LP), right-hand circular polarization (RHCP) or left-hand circular polarization (LHCP) by means of 4 independently biased PIN diodes. The proposed antenna is designed and simulated using electromagnetic simulation software CST Microwave Studio. In order to experimentally validate the design, a prototype is fabricated on a 1.6 mm thick RT Duroid substrate of relative permittivity εr = 2.2. The performance of the antenna is validated experimentally using 16 PIN diodes. The simulation and measured results for all the polarization states of the array antenna are found to be in good agreement. The measured results have established the polarization reconfigurable ability of the antenna for 5.7–6.0 GHz operating band. The proposed antenna is suitable for C-band point-to-point communication applications.
关键词： PIN diode switch,polarization reconfigurable,corporate feed network,reconfigurable antenna,Array antenna,circular polarization
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Broadband Tri-Polarization Reconfigurable Magneto-Electric Dipole Antenna
摘要： A broadband tri-polarization reconfigurable magneto-electric dipole antenna is presented in this paper. This proposed antenna structure mainly consists of a conventional ME antenna fed by a Γ-probe, four parasitic patches, a rectangular ground plane and four PIN diodes including their corresponding bias circuit. The size of the rectangular ground plane is of 250×180 mm2 and its profile is of 50 mm. Each of the four PIN diodes is controlled by its corresponding bias circuit independently. The proposed antenna is capable of providing three different polarization states including one linear polarized operation mode and two orthogonal circular polarized modes. The simulated overlapped bandwidth (S11≤-10 dB) is about 59% (1.36 GHz~2.5 GHz) for the one linear polarized mode and 78.7% (1.07 GHz~2.46 GHz) for the two orthogonal CP modes. In additional, the simulated overlapped 3-dB AR bandwidth is about 37.2% from 1.2 GHz to 1.75GHz. Detailed design considerations of the proposed antenna are described in the following sections.
关键词： reconfigurable antenna,broadband antenna,magneto-electric antenna,tri-polarization
更新于2025-09-23 15:22:29
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Differentially-Fed Aperture-Coupled Magneto-Electric Dipole Antenna With Continuously Variable Beamwidth
摘要： A beamwidth reconfigurable linear array antenna utilizing three magneto-electric (ME) dipole antenna elements with no need for a complex feeding network is presented. In this design, the ME dipole antenna elements are differentially excited by three parallel transverse resonant slots etched on the broad wall of a substrate integrated waveguide (SIW) cavity. By symmetrically embedding four copper posts that are connected to varactor diodes between the adjacent slots, the electric field perturbation in the SIW cavity can be realized by manipulation of the varactors. In other words, altering bias voltage of all the varactors simultaneously could offer granular control over the excitation amplitude and phase of the antenna elements. Consequently, continuously variable beamwidth of the antenna can be obtained under electronic control. A fully operational prototype was designed, fabricated, and tested to validate the proposed design. Measured results indicate that the overlapped -10 dB impedance bandwidth of the proposed antenna is 19.6% and the half-power beamwidth (HPBW) in the E-plane is capable of varying from 39° to 107° within the operating frequency band.
关键词： Beamwidth reconfigurable antenna,varactor diode,substrate integrated waveguide (SIW),magneto-electric (ME) dipole
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A Wide-Angle Pattern Reconfigurable Antenna Realized by Meta-surface
摘要： This paper presents a wide-angle pattern reconfigurable antenna which has good directivity. The main lobe direction of the pattern can be switched between (cid:537)=±45o when (cid:182)=90o in the whole working frequency band. In addition, the structure of the antenna can be divided into three layers. The bottom layer is a feed line. The middle layer is the ground with slots. And the top is a novel meta-surface (MS). Reconfiguration is designed to achieve by controlling the state of PIN diode switches on the MS. This antenna is low profile and small volume. And the working frequency is from 4.95GHz to 5.05GHz.
关键词： pattern reconfigurable antenna,Wide-angle,MS
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Wideband Polarization Reconfigurable Antenna Using Quasi-Cross-Shaped Coupling Slot
摘要： A quasi-cross-shaped coupling slot antenna with a Wilkinson power divider network is proposed to realize the wideband linear polarization (CP), left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The quasi-cross-shaped coupling slot generates two orthogonal linear polarization with high isolation. Four pairs of PIN diodes are used in four branches of the Wilkinson power divider network to alter the current flow path so as to generate a phase difference of 0° or ±90° and achieve the polarization reconfiguration. The results show that the proposed antenna has a 10-dB impedance bandwidth of 2.80- 3.54GHz (0.74GHz, 23.3%) for LP and 2.82-3.49GHz (0.67GHz, 21.2%) for CP. The 3-dB axial ratio (AR) bandwidth is 2.92- 3.43GHz (0.51GHz, 16.1%) for LHCP and 2.88-3.43GHz (0.55GHz, 17.4%) for RHCP. In addition, the antenna achieves a high average realized a gain of 9.1dBi.
关键词： reconfigurable feed network,wideband,slot antenna,polarization reconfigurable antenna
更新于2025-09-10 09:29:36
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Antena impresa invertida reconfigurable en frecuencia a base de una microdescarga de plasma
摘要： This paper proposes the study of an inverted microstrip plasma-based reconfigurable antenna. The scope is to generate controlled microplasma inside the cavity between the antenna ground plane and its main conductor. This plasma will modify the resonant frequency of the antenna. The interest of using a plasma discharge as an active reconfigurable element is its switching time and mainly its capability of handling high microwave power. It was demonstrated, theoretically, that the reconfiguration frequency of a microstrip patch antenna with a microdischarge in its cavity, depends on the electron density of the plasma. Furthermore, a prototype of an X-Band inverted microstrip patch antenna, which integrates a microdischarge, was implemented. The measured frequency excursion for this prototype was 180 MHz.
关键词： Reconfigurable antenna,frequency tuning,plasma discharge
更新于2025-09-09 09:28:46
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Antena de Parche Cortocircuitado con Polarización Circular y Sentido de Giro Reconfigurable para Aplicaciones en Satélites de Reducido Tama?o
摘要： This paper presents the design and characterization of a circular microstrip patch antenna, fed by a hybrid quadrature coupler to achieve reconfigurable circular polarization. The radiating element has a radius of 20.3mm and the overall dimensions of the antenna are 76mm x 76mm X 2.03mm, suitable to attaching it to one of the faces of a satellite (CubeSat 1U). The measurement results of the prototype show a maximum gain of ??0 = 6,04?????? and axial ratio bandwidth of 48.56MHz (2%) respect to 2dB at the center frequency of ??0 = 2,44??????; an impedance bandwidth of 27.44% respect to the magnitude of the reflection coefficient of ??11 < ?10 ????, in the range of 2,295GHz to 3,025GHz at the center frequency of ??0 = 2,44??????.
关键词： circular polarization,shorted circular patch antenna,reconfigurable antenna,satellite application
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Electronically Steerable Circularly Polarized Planar Antenna
摘要： This paper presents a steerable, circularly polarized planar antenna operating at 2.45 GHz. The design employs a central omni-directional circularly polarized active element surrounded by electronically controllable parasitic elements that are used to steer the beam in the desired direction. The proposed antenna is capable of steering the beam in an arbitrary direction. The antenna has a 3 dB gain and an axial ratio of less than 2 dB in the direction of radiation.
关键词： omnidirectional,circular polarization,parasitic antenna,reconfigurable antenna
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Polarization Reconfigurbale Antenna with Liquid Metal
摘要： In this paper, we present a polarization reconfigurable liquid dielectric resonator antenna (DRA) incorporating liquid metal. For the liquid dielectric solution, we use ethyl acetate and for the liquid metal solution, an alloy called Galinstan was used. Before introduction of the liquid metal electric field within the DRA was orientated along the Y-axis. Then by injecting the liquid metal into the liquid dielectric, the electric field rotated 45 degrees. Consequently, polarization reconfiguration was achieved. All of the results presented in this paper were obtained through computer simulation in HFSS.
关键词： liquid metal,Liquid dielectric resonator antenna,polarization reconfigurable antenna
更新于2025-09-04 15:30:14