Circuital approach to design FSS spatial filter
05 Mar 2015-pp 1-5
TL;DR: A circuital approach is used to develop a better understanding of FSSs and to attain correct model and results are produced using Agilent ADS software.
Abstract: This paper presents a circuital approach to design a Frequency Selective Surfaces (FSSs) spatial filter. Spatial filter is used to extract the electromagnetic waves in spaces. A conducting sheet perforated with apertures or an array of periodic metallic patches constitute FSSs and it is usually designed to provide four standard spectral response: low-pass, High-pass, band-pass and band-reject. Circuital approach is used to develop a better understanding of FSSs and to attain correct model. A band-pass filter with frequency range from 2GHz–8GHz and band-stop filter with frequency range from 6GHz–13GHz was designed using FSSs. Properties of FSSs are evaluated through simple and accurate equivalent circuit. Simulation results for both filters are produced using Agilent ADS software.
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26 Apr 2000
TL;DR: In this article, the authors present a comparison of band-pass and Dichroic filter designs for one and two-dimensional periodic structures, and present an overview of the current state-of-the-art.
Abstract: General Overview. Element Types: A Comparison. Evaluating Periodic Structures: An Overview. Spectral Expansion of One- and Two-Dimensional Periodic Structures. Dipole Arrays in a Stratified Medium. Slot Arrays in a Stratified Medium. Band-Pass Filter Designs: The Hybrid Radome. Band-Stop and Dichroic Filter Designs. Jaumann and Circuit Analog Absorbers. Power Handling of Periodic Surfaces. Concluding Remarks and Future Trends. Appendices. References. Index.
3,896 citations
TL;DR: In this paper, a three layer structure composed of three metal layers, separated by two electrically thin dielectric substrates, is proposed for conformal frequency selective surfaces. But, unlike traditional third-order bandpass FSSs, which are usually obtained by cascading three identical first-order frequency selective surface (FSSs) a quarter wavelength apart from one another and have thicknesses in the order of lambda/2, the proposed structure has an extremely low profile and an overall thickness of about lambda/24, making it an attractive choice to conformal FSS
Abstract: We demonstrate a new class of low-profile frequency selective surfaces (FSS) with an overall thickness of lambda/24 and a third-order bandpass frequency response. The proposed FSS is a three layer structure composed of three metal layers, separated by two electrically thin dielectric substrates. Each layer is a two-dimensional periodic structure with sub-wavelength unit cell dimensions and periodicity. The unit cell of the proposed FSS is composed of a combination of resonant and non-resonant elements. It is shown that this arrangement acts as a spatial bandpass filter with a third-order bandpass response. However, unlike traditional third-order bandpass FSSs, which are usually obtained by cascading three identical first-order bandpass FSSs a quarter wavelength apart from one another and have thicknesses in the order of lambda/2 , the proposed structure has an extremely low profile and an overall thickness of about lambda/24 , making it an attractive choice for conformal FSS applications. As a result of the miniaturized unit cells and the extremely small overall thickness of the structure, the proposed FSS has a reduced sensitivity to the angle of incidence of the EM wave compared to traditional third-order frequency selective surfaces. The principles of operation along with guidelines for the design of the proposed FSS are presented in this paper. A prototype of the proposed third-order bandpass FSS is also fabricated and tested using a free space measurement system at C band.
146 citations
"Circuital approach to design FSS sp..." refers background in this paper
...The unit cell of the proposed FSS is composed of a combination of resonant and non-resonant elements. proposed structure has an extremely low profile and an overall thickness of about A/24 [5]....
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TL;DR: In this article, a generalized synthesis procedure for low profile frequency selective surfaces (FSS) with bandpass responses of odd-order (N = 3,5,7,...) is presented.
Abstract: We present a generalized synthesis procedure for designing low-profile frequency selective surfaces (FSS) with bandpass responses of odd-order (N = 3,5,7,...). The FSSs designed using this technique use a combination of resonant and non-resonant sub-wavelength constituting unit cells with unit cell dimensions and periodicities in the order of 0.15 λ0, where λ0 is the free space wavelength. The main advantage of using this technique, compared to traditional FSS design techniques, is that it allows for the design of low-profile and ultrathin FSSs that can provide sharp frequency selectivity. An Nth order FSS designed using this technique typically has an electrical thickness in the order of ~ (N - 1) λ0/50 which is significantly smaller than the overall thickness of a traditionally designed Nth order FSS (~ (N - 1) λ0/4). The proposed synthesis procedure is validated for two FSS prototypes having third- and fifth-order bandpass responses. Principles of operation, detailed synthesis procedure, and implementation guidelines for this type of FSS are presented and discussed in this communication.
91 citations
"Circuital approach to design FSS sp..." refers background in this paper
...The main advantage is the design low-profile and ultrathin FSSs that can provide sharp frequency selectivity [6]....
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TL;DR: In this paper, a very thin-layer modified miniaturized-element frequency-selective surface (FSS) has been developed to achieve low thickness solution and improved functionality, enabling implementation of higher order spatial filters over low profile conformal antenna arrays.
Abstract: This paper presents a novel multipole miniaturized-element frequency-selective surface (FSS) having a very low thickness and a desired multipole frequency response. For this design, new miniaturized elements for the FSS are developed to achieve low thickness solution and improved functionality. The proposed FSS enables implementation of higher order spatial filters over low-profile conformal antenna arrays. First, design of a very thin-layer modified miniaturized-element FSS producing a single-pole bandpass response in addition to a transmission zero is presented. The modified design is just a single-sided circuit board with a particular unit cell consisting of a loop centered within a wire grid. Next, using a similar metallic pattern on the other side of a very thin substrate, a dual-bandpass frequency response is produced. This response is achieved by choosing proper dimensions for the loops and wire of each layer and by appropriately positioning the layers with respect to each other. To establish a benchmark, dual-pole FSSs using cascaded layers of a previously designed miniaturized-element FSS are considered. In comparison, the modified dual-bandpass design has only two metal layers, instead of four, and a single substrate, instead of three. The proposed multipole FSS has a thickness of lambda/300 which is six times thinner than the benchmark structures. Moreover, the frequency response of the new FSS shows higher out-of-band rejection values. Performance of the multipole screens is tested by fabricating FSSs with maximally flat and dual-bandpass responses and measuring their frequency responses using a standard measurement setup in a free-space environment.
89 citations
TL;DR: In this article, a dual-band frequency selective surface (FSS) with miniaturized element was proposed for low frequency low-frequency communications. But the authors only considered the two passband responses of the FSS and reduced the slot sizes to make the element miniature and compact.
Abstract: In this paper, we propose a dual-band frequency selective surface (FSS) in low frequencies with miniaturized element. A dual- concentric square element with two difierent slot sizes is constructed to realize dual-band passband responses. Each passband is realized by a square slot structure. Besides, we reduce the slot sizes to make the element miniature and compact. Based on this technique, a dual- band FSS with miniaturized element in low frequencies is designed. Both the simulation and experiment results show that such a FSS owes its advantages to miniature element, stable performance with various incident angles and difierent polarizations, which is suitable for dual- band shipboard communication.
25 citations
"Circuital approach to design FSS sp..." refers methods in this paper
...Besides, we reduce the slot sizes to make the element miniature and compact [12]....
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