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- 摘要
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- 实验方案
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Design and equivalent circuit model extraction of a third-order band-pass frequency selective surface filter for terahertz applications
摘要： In this paper, a third-order band-pass frequency selective surface (FSS) filter is proposed for terahertz applications. The presented FSS filter is designed based on miniaturized unit cells and a fractional bandwidth of 72% around 0.775 THz is achieved. In addition, a high transmission magnitude is obtained with an acceptable flatness in comparison to previous reports. In order to verify the numerical results, an equivalent circuit model of the proposed spatial filter is introduced considering both normal and oblique incident angles. The sensitivity of the filter with respect to the incident wave angle is investigated in the range of 0–60° whereas the obtained performance is acceptable for various incident angles in the mentioned range. Moreover, the effects of altering different geometrical parameters are studied and justified based on the extracted equivalent circuit model.
关键词： Miniaturized elements,Terahertz filter,Equivalent circuit model,Metamaterial,Frequency selective surface
更新于2025-09-19 17:15:36
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[IEEE 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Granada, Spain (2019.9.9-2019.9.13)] 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - 3-D dual-band FSSs based on multiple square coaxial waveguides
摘要： In this paper, a kind of dual-band three-dimensional (3-D) frequency selective surfaces (FSSs) based on multiple square coaxial waveguides (SCWs) are proposed. Through a simple design, transmission poles are intrinsically produced by the square slot resonances in two SCW propagation paths, and another transmission pole is generated by a parallel-plate waveguide (PPW) propagation path. With the help of these three transmission poles, a closely-spaced dual-band 3-D FSS can be achieved with the band ratio 1.118. In order to further extend the application of the proposed structure, a modified design is then exhibited. One pair of short SCW resonant elements is created in each SCW propagation path. As a result, each SCW propagation path can provide two transmission poles for a flat passband by the odd- and even-mode coupling. Moreover, the transmission zeros are located at each sides of passbands, leading to both-sided sharp roll off. The unit cell size of the modified design is reduced remarkably. The E-field analysis of transmission zeros/poles is given to explain the operating principle of two proposed FSSs. The simulated results show that the proposed FSSs can achieve stable responses to variations of incident angle from 0° to 45° for both TE and TM polarizations.
关键词： frequency selective surface (FSS),band ratio,dual-band,high selectivity,square coaxial waveguides (SCWs)
更新于2025-09-19 17:13:59
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Design and Analysis of Wideband Low-Scattering Endfire Antenna Using Moth Tail-Inspired Metamaterial Absorber and Surface Waveguide
摘要： This paper presents a wideband endfire antenna co-designed with broadband low-scattering characteristics. The wideband reflection and endfire radiation attribute the success to the supported dual-resonance surface waves, and the broadband low scattering owes to the combination of a metamaterial absorber (MA) absorption and an incident penetration of a frequency selective surface (FSS). Based on the transmission line model, a surface waveguide (SWG) which can support dual-resonance surface waves is adopted and analyzed to realize the wideband reflection response (4.95 ~ 6.83 GHz) and endfire radiation. Also, the SWG can be seen as an FSS for the normal incidence. In addition, a wideband MA, which is inspired by the luna moth's escape from bat attack, is designed and integrated with the SWG to realize low back radar cross section (RCS) in the frequency range from 0.5 to 12.5 GHz. The reflection, radiation and scattering performance are validated by the full-wave simulation and experimental verification.
关键词： Frequency selective surface (FSS),radar cross section (RCS),surface wave,moth tail-inspired metamaterial absorber (MA)
更新于2025-09-16 10:30:52
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[IEEE 2018 IEEE MTT-S International Microwave and RF Conference (IMaRC) - Kolkata, India (2018.11.28-2018.11.30)] 2018 IEEE MTT-S International Microwave and RF Conference (IMaRC) - 3D Frequency Selective Surfaces based on Substrate Integrated Waveguide Technology
摘要： In this paper, a novel design technique for designing 3D frequency selective surfaces (FSS) is proposed based on substrate integrated waveguide (SIW) cavity technology. The proposed design comprises of two tightly coupled FSS elements through the series of periodically spaced metallic vias which are separated a by a finite gap. The structure exhibits passbands characteristics with a relative bandwidth of 14.14%. Further, it exhibits two sharp roll-off performance characteristics on either edges of transmission frequency with two transmission zeros. The parametric study has been conducted to analyze its effect on frequency response of the structure. Furthermore, the material characteristics are derived to analyze the material behavior of the structure.
关键词： 3D FSS,Substrate integrated waveguide,Electromagnetic materials,reflection coefficient,transmission coefficient,EM wave propagation,Frequency selective surface (FSS)
更新于2025-09-12 10:27:22
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Dual-bandpass 3-D FSS with close band spacing based on multiple square coaxial waveguides
摘要： A three-dimensional (3-D) frequency selective surface (FSS) based on multiple square coaxial waveguides (SCWs) is proposed, which realizes a dual-bandpass response with close band spacing. In the unit cell of the proposed 3-D FSS, two concentric SCW propagation paths and one parallel-plate waveguide (PPW) propagation path are constructed by utilizing three square metallic tubes. Each SCW propagation path intrinsically generates one transmission pole by the square slot resonance, and the PPW propagation path produces another transmission pole by the half-wavelength resonance. In addition, two transmission zeros are introduced due to the counteraction of out-of-phase signals between di?erent paths, improving the frequency selectivity. After properly adjusting the design parameters, two desired passbands are obtained around 4.4 and 4.845 GHz, and the band ratio is only 1.1. Through the electric-?eld distributions, equivalent circuit model and parameters study, the operating principle of the proposed 3-D FSS is investigated. A prototype of the proposed 3-D FSS is fabricated and measured. The measured results show that the proposed design can achieve a stable response under the incident angles up to 45° for both TE and TM polarizations.
关键词： square coaxial waveguides (SCWs),frequency selective surface (FSS),dual-bandpass,dual-polarized,close band spacing
更新于2025-09-12 10:27:22
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Polarization-Insensisitve Broadband Multi-layered Absorber Using Screen Printed Patterns of Resistive Ink
摘要： Design and implementation of a broadband polarization-insensitive multi-layered microwave absorber using resistive ink has been presented here. The proposed absorber is constructed using layers of resistive surface where each layer consists of periodic arrangement of resistive patterns printed on a low cost FR4 sheet using resistive ink. Due to the multilayered nature, the proposed absorber shows broadband absorption having simulated reflection co-efficient less than -10dB in the frequency range from 2.00 GHz to 18.50 GHz under normal incidence which covers the entire S, C, X and Ku bands with the smallest thickness of 0.082λL (at lowest operating frequency of the absorption band) as compared to the state-of the-art absorbers. In order to validate the proposed absorber, the equivalent circuit model has also been presented. The equivalent circuit model shows good match with the proposed absorber. The proposed absorber is experimentally verified and the experimental results shows good agreement with the simulated results.
关键词： Frequency selective surface,resistive ink,multi-layered absorber,Broadband absorber
更新于2025-09-11 14:15:04
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[IEEE 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Xuzhou (2018.7.21-2018.7.24)] 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Active Frequency Selective Surface Based L-band Noise Rejection Conformal Radome
摘要： Active frequency selective surfaces have long been employed in the field of mutual coupling suppression and are receiving increasingly more attention due to its remarkable performances and flexibility. However, the frequency tunable range of the resonators is usually not wide enough, especially for the band-stop ones. Meanwhile, a tunable frequency selective surface usually requires a bias network, which makes the design even more difficult and limits the use of active frequency selective surfaces in building radomes. In this work, we make use of a previously designed broadband active frequency selective surface to realize a conformal tunable radome, the measured resonant frequency of which is tuned from 935MHz up to 2.405 GHz, and the designed structure is capable of suppressing narrow band noise effectively through the whole L-band.
关键词： active frequency selective surface,tunable frequency selective surface,radome,metamaterial
更新于2025-09-10 09:29:36
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Four-bit instantaneous frequency measurement systems based on frequency selective surfaces
摘要： This paper presents four (FSSs) to be used in an instantaneous frequency measurement (IFM) systems. The FSS based on simple dipoles have a frequency response corresponding to the characteristics of frequency discriminators. An IFM system with 4-bits is shown with resolution around 300 MHz. The system contains 16 distinct frequency sub-bands between 3.21 and 8.75 GHz. CST software simulations and measurements of insertion loss are presented and compared with theoretical results to provide the binary codes of the system.
关键词： frequency discriminators,IFM,frequency selective surface (FSS)
更新于2025-09-10 09:29:36
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Electronically Beam-Steering Antenna with Active Frequency Selective Surface
摘要： A beam-sweeping antenna utilizing a novel active frequency selective surface (FSS) is developed in this letter. It is comprised of a simple dipole and a cylindrical FSS formed by six columns of unit cells. The dipole used as a radiating source is situated at the center of the cylindrical FSS. The radiation pattern of the antenna could be reconfigured by controlling the states of the PIN diodes in the FSS. The dimension of the whole antenna is 0.75 λg × 0.75 λg × 1.57 λg (λg is the guided wavelength at its resonant frequency). Experimental results demonstrate that the presented beam-steering antenna can operate at 2.45 GHz and the main beam can be swept across the whole azimuth plane with a peak gain of 8.15 dBi.
关键词： beam-sweeping,frequency selective surface,Radiation pattern,beam-switching
更新于2025-09-10 09:29:36
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High efficient linear polariser using FSS structure
摘要： A linear polarisation converter surface with broadband and high-efficiency properties is proposed. The proposed frequency selective surface (FSS) polariser consists of two-corner-cut diagonal rectangular printed on a substrate backed by a pinwheel loop shape ground. The combination of two-corner-cut diagonal rectangular patch and pinwheel loop shape ground contributes to bandwidth expansion. Numerical results indicate that the FSS structure is capable of converting x or y polarised incident wave to the relevant cross-polarised wave in a wide frequency range from 7.5 to 24.5?GHz with a fractional bandwidth of 106% for ?10?dB rxy reflection amplitude. In addition, the ryy and rxy reflection coefficients of the proposed unit-cell present slight variation for different incident angles up to 40°, which verifies the applicability of the proposed FSS structure in a practical environment. For experimental validation, a prototype of the FSS structure is fabricated and reflection parameters of the proposed structure are measured which agree well with corresponding simulations. Due to the minimal dependency on the angle of incidence and non-uniform ground plane the proposed polarisation converter unit-cell can be a possible choice for secure building applications.
关键词： broadband,linear polarisation converter,frequency selective surface,FSS structure,high-efficiency
更新于2025-09-10 09:29:36