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- 摘要
- 关键词
- 实验方案
- 产品
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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) - Dual Circularly Polarized Antennas with Low Cross-Polarization for GNSS-R Applications
摘要： Global Navigation System-Reflectometry (GNSS-R), has gained increasing interests as an efficient tool for remote sensing. It is based on the concept of utilizing the received signals reflected from the Earth’s surface. Several GNSS-R system configurations were proposed depending on different retrieval algorithms. In a GNSS-R system, the antenna plays a key role as a receiving component. In this paper, in-situ measurements using a commercial dual circular polarized antenna receiving both the left-hand and right-hand circular polarization reflected from the ground are analyzed. A low cost and compact dual-port circular polarized patch antenna is designed and realized to overcome the limitations of the previous configuration. The prototype shows a low level of cross polarization suitable for GNSS-R application.
关键词： circular polarization,dual polarization,patch antenna,remote sensing of soil,GNSS-R
更新于2025-09-04 15:30:14
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A tunable ultra-broadband linear-to-circular polarization converter containing the graphene
摘要： In this paper, a tunable ultra-broadband linear-to-circular polarization converter (LCPC) in terahertz regime containing the graphene is proposed, which are composed of two "I"-shaped gold resonators, a strip-shaped graphene sheet, two dielectric layer and a bottom gold reflector. The proposed LCPC can convert the linearly polarized wave into circularly polarized wave in an ultra-broadband frequency range which can be expanded to the lower frequencies by decreasing the Fermi energy (??f ) of the graphene in terahertz region. When ??f = 0.4 eV, 0.6 eV, 0.8 eV and 1.0 eV, the axial ratio band of the proposed LCPC which is less than 3 dB are covered 0.9248～2.2880 THz, 0.9408～2.2893 THz, 0.9665～2.2803 THz, and 0.9746～2.2780 THz, whose relative bandwidths are 84.86%, 83.49%, 80.93% and 80.15%, respectively. The maximum 3 dB axial ratio band is located at 0.9248～2.2880 THz and its relative bandwidth is 84.86% at the case of ??f = 0.4 eV. The polarization conversion rate curves, reflection phase curves, surface current and electric field diagrams are analyzed to elucidate the physical characteristics of the presented LCPC. In addition, the effect of parameters a, b and c on the axial ratio band are also discussed, respectively. This design offers an effective way to realize the reconfigurable LCPC, and also has enormous potential value in realizing the THz devices.
关键词： Graphene,Ultra-broadband,Tunable line-to-circular polarization converter
更新于2025-09-04 15:30:14
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Deployable Linear-to-Circular Polarizer using PDMS Based on Unloaded and Loaded Circular FSS Arrays for Pico-Satellites
摘要： In this paper, flexible, deployable linear to circular polarizers designed on Polydimethylsiloxane (PDMS) are proposed for the first time to the best of our knowledge. ShieldIt textile is used as the conducting elements of two types of unit elements: a loaded and an unloaded circular element on rear side of the substrate, and a generic rectangular element on the reverse side of the substrate in both designs. The unloaded circular unit cell is sized at 46 mm × 56.17 mm × 3 mm, whereas the loaded cell is slightly larger, at 72 mm × 60 mm × 3 mm. The overall performance of the polarizers are evaluated in terms of phase difference, conversion efficiency, and axial ratio (AR). Besides that, the bandwidth confirming 40? to 45? ellipticity are also assessed. Measurements indicated good agreements with simulations and operation from 2.39 GHz to 2.45 GHz. Both structures exhibited more than 90 % of conversion efficiency within the range of 2.34 to 3 GHz (for the loaded circular unit cell) and from 2.36 to 3 GHz (for the unloaded circular unit cell). Moreover, satisfactory performance is observed in terms of ellipticity (40? to 45?), with bandwidth varying from 8.67 % for the unloaded design and 13.82% for the loaded design. The unloaded structure exhibited a fractional bandwidth of 36.36 % (from 1.98 GHz to 2.86 GHz) satisfying the 3 dB axial ratio in simulations, and 32.64 % (from 2.00 GHz to 2.78 GHz) when evaluated experimentally. Conversely, the loaded design showed only 12.58 %. An equivalent circuit model has also been proposed and validated via comparison between the circuit and EM simulations. Finally, the polarizers are also assessed in different bending conditions due to the use of flexible materials. Their performance variation are analyzed prior to the proposal of a suitable deployment process.
关键词： linear-to-circular polarization,pico-satellite,Flexible polarizer
更新于2025-09-04 15:30:14
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An Implantable Wideband Circularly Polarized Microstrip Patch Antenna via Two Pairs of Degenerate Modes
摘要： This paper presents a design approach to developing a wideband circularly polarized (CP) microstrip patch antenna (MPA) embedded in the human body. To achieve this goal, a pair of high-order degenerate modes (TM30 and TM03) in MPA have been excited and lowered for resonance in proximity to a pair of fundamental degenerate modes (TM10 and TM01). The proper disturbance of these two pairs of radiative resonant modes can contribute to the generation of two CP radiating waves at two near-by operating frequencies, aiming to realize CP radiation in a wide operating band covered by these two frequencies. A novel implantable wideband CP MPA is proposed and developed due to the emergence of two minima in the axial-ratio (AR) frequency response. The designed MPA is then demonstrated to tremendously achieve the wide 3-dB AR bandwidth which covers the 2.4 to 2.48 GHz ISM-band in the cubic human skin model. Moreover, the proposed CP MPA shows good tolerance to the variety of tissue according to our study on sensitivity and model integrity. Finally, the designed CP MPA is fabricated and tested, and a good agreement exists between measured and simulated results in a wide frequency region.
关键词： Implantable Antenna,Lower and Upper Degenerate Modes,Wide Bandwidth,Circular Polarization
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) - Design of Multiband Circularly Polarized Antenna Arrays for GNSS Applications
摘要： Two Multiband circularly polarized antenna arrays are proposed in this paper. Both of the antenna arrays consist of four antenna elements. Each antenna element has three patches, generating circular polarization electromagnetic wave at three frequency bands. The antenna arrays can operate at GPS L1, L2, and L5 bands. The slits are used in the second antenna array to achieve lower mutual coupling between the antenna elements compared with the first antenna array. Simulations and measurements are carried out to study the antenna element and antenna arrays’ performances in terms of impedance matching, axial ratio, gain and radiation patterns. Both of simulation and measurement results are shown to illustrate the good performance of the proposed antenna arrays. It is very suitable for multi-functional GNSS applications.
关键词： GNSS,Circular polarization,multiband antenna,microstrip antenna
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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[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) - Substrate-insensitive Phased Array with Improved Circularly-polarized Scan Angle for 5G Mobile Terminals
摘要： This paper introduces a concept of a substrate-insensitive circularly-polarized phased array for 28 GHz mobile terminal applications. Each array element is a metalized cross slot antenna, which covers the bandwidth of 25-31 GHz. The performance of the designed circularly-polarized antenna is insensitive to substrate permittivity and loss tangent. By adjusting the edge effects of the phased array, the array scan angle with circular polarization can be efficiently improved. User hand effect on the array scan angle with circular polarization is investigated. The proposed mobile terminal phased array is fabricated. S parameters, radiation patterns and realized gain of all the array elements are measured. The measured results agree well with the simulations.
关键词： scan angle,mobile antenna,circular polarization,5G application,substrate-insensitive antenna
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) - 140 GHz Linear to Circular Polarization Convertor Based on Modified Cross Slot Frequency Selective Surface with High Selectivity
摘要： A 140 GHz linear to circular polarization converter based on a frequency selective surface (FSS) with high selectivity is proposed and designed in this paper. The periodic element of the converter includes a square substrate integrated waveguide (SIW) cavity and two cross slots with stubs etched on the top and bottom conductor claddings of the cavity. Based on the SIW cavity, a transmission pole is provided to improve passband characteristics and sideband selectivity. Besides, this THz converter can be easily fabricated using normal PCB process instead of compacted and high-cost technologies.
关键词： high selectivity,frequency selective surface (FSS),circular polarization (CP),Terahertz (THz) technology,substrate integrated waveguide (SIW) cavity
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) - Compact UWB Circularly Polarized Dielectric Rod Antenna Design
摘要： A novel circular-polarization (CP) ultra-wideband dielectric rod antenna design has been developed for operating from X to Ka band. The radiation tip design was based on the previous dual linear-polarization 3-layer dielectric rod design. A novel CP wave-launcher composed of conical spiral arms was developed. This launcher does not require balun or quadrature-phase hybrid. In addition, a novel quadrifilar conducting enclosure was introduced to minimize overall antenna diameter while maintaining good axial ratio at the low frequency end. The simulated antenna performance exhibits an axial ratio (AR) of less than 3 dB, stable gain, stable beamwidth, and stable phase center from 10 to 40 GHz.
关键词： Circular polarization,Ultra-wideband antennas,Dielectric antenna
更新于2025-09-04 15:30:14