Analysis of Stop-Band Frequency Selective Surfaces With Dürer's Pentagon Pre-Fractals Patch Elements

In this paper, a frequency selective surface (FSS) element has been presented based on substrate integrated waveguide (SIW) technology for improved EM performance. The SIW cavity results in the generation of additional resonance, which combines with the resonance of FSS shows a relatively wider bandwidth (BW). Furthermore, the FSS based on SIW exhibits a sharp roll-off performance with flat transmission characteristics. The FSS element is designed to operate in Ku-band near 15.0 GHz for satellite application. Two design examples have been reported for the dual band and broadband response. The estimated results have proven the superiority of the SIW cavity FSS over its conventional form.

This paper presents a design of dualband frequency selective surface (FSS) element design based on SIW cavity (SIWC) technology and its performance analysis. The proposed dualband FSS is modelled using a combination of two FSS elements. A cross-slot element has been enclosed by a square slot to design the proposed shape. The structure shows dualband response at two different frequency bands C- and Ku-bands with sharp roll-off performance characteristics. The performance of the structure has been estimated using commercial CST Microwave studio. The simulation results show the higher selectively, very good isolation between the bands and stable performance characteristics compared with its equivalent conventional planar version.

This paper presents an analysis of the characteristics of the frequency selective surface (FSS) by means of equivalent circuit models. In order to determine the circuit element parameters of the FSS with resonant elements of arbitrary shape, the eigenvalue problem of the matrix equation is solved and the Q curve of each resonance is derived from the frequency dependence of the reactance obtained from the characteristic current distributions at resonance. By equating this Q curve with that for the equivalent circuit, the circuit parameters are derived. As an example of analysis by the present method, the circuit element parameters of patch-type resonant elements designed by us using the genetic algorithm (GA) are derived. The characteristics of the dielectric-loaded FSS for the C/Ka band are analyzed by means of the equivalent circuit. The usefulness of the proposed method is verified by comparison of the frequency characteristics obtained by the method of moments and by the equivalent circuit. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(6): 9–17, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20162

In this paper a modified method based on FDTD method is used to analyze frequency selective surfaces with periodic boundary condition. Computation results are compared to that from other scholars. Good agreement has been observed. Multiplexer, which consists of two sheets of FSS, is simulated and good performance has been obtained over a band from 100 GHz to 450 GHz.

In this paper, combined elements method is introduced to achieve dual stop-band frequency selective surface (FSS). Later, a dual-band WLAN antenna is designed and the centre frequency is at 2.4GHz and 5.4GHz which accord with the FSS in this paper. We use FSS as dual-band WLAN antenna's reflection plan to improve the performance of antenna. The analysis and results of antenna and FSS are given. The results show that antenna's gain can be improved after the FSS is placed as the reflection plane. This is a new research area which have great prospect in the design of antenna combined with FSS.

Frequency selective surface (FSS) is a two-dimensional periodic structure. It exhibits total reflection and transmission in the neighborhood of the element resonances. As it performs as a filter, FSS is widely used in the fields of microwave and optics. In this paper, the finite element method is used to analysis frequency selective surface and study on the feasibility of Ansoft HFSS software for frequency selective surface simulation. Hexagonal element of frequency selective surface is as an example to explore the simulation method and the process of Ansoft HFSS. Through the comparison of the simulation curves and the measured curves of hexagonal element frequency selective surface film by photoetching technology, the simulation method of Ansoft HFSS software for frequency selective surface is correct. At the same time, this paper further verified the reliability of the simulation through the example of the ring and the cross unit structure.

Wave concept iterative procedure (WCIP) is used to analyze dual‐band and enhanced band frequency selective surfaces (FSS). In the metallic U‐shaped simple FSS, a fine‐tune of the two rejected bands is insured by varying independently the length of the two parallel U‐shaped FSS strips. The dual band response can also be obtained from the two‐level rectangular conducting patches FSS. An enhanced rejecting bandwidth is observed for FSS with two square ring printed on each substrate side. The WCIP results are successfully compared with measurements and HFSS results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:836–839, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25073

Computer programs for simulation of microwave structures are becoming accessible. However, to understand electromagnetic fields behavior and to comprehend the numerical model limitations, a solid theoretical basis and computational expertise to enable the implementation of the own programs remains indispensable. The wave concept iterative procedure, WCIP, is a numerical technique easy to understand, that can be implemented without great efforts. In this work the WCIP is applied to analysis of frequency selective surface, FSS, with Koch Island patch elements. Obtained numerical results are compared to others obtained by the use of Ansoft Designer <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">™</sup> software and to experimental ones.

A loaded gridded Jerusalem cross element is analyzed and predicted its plane-wave transmission/reflection characteristics for a normal and oblique angle of incidence using an equivalent circuit model. Further, the structural behaviour of its conformal bent is analyzed by bending the structure at a conformal radius of 25 mm. The modes of resonance of the structure are examined, current is largely confined at the E-plane arm at the resonance frequency. The deviation in the EM performance of planar and conformal structures have been studied for different design parameters. A Commercial full-wave simulator is employed to validate the designed analytical expressions of the element and for further analysis.

A novel approach to analyze FSS structures is used whereby the Ewald transform technique, in conjunction with a particular choice of basis function, is shown to reduce the complexity of the problem formulation and greatly improve the convergence rate of the MoM solution for periodic structures. In particular, we consider wire-type geometries, which need not be confined to a single plane configuration, to demonstrate the effectiveness of this method.

This paper proposes a fractal square loop frequency selective surface (FSS) with dual-band stop behavior. The FSS elements are etched on FR-4 substrate to attenuate signals at GSM900, GSM1800 and IMT2000 frequency bands while transmitting other microwave signals. The unit cell geometry is a modification of the conventional square loop which shows an improvement in stability for oblique incidence up to 45° for both TE and TM polarizations. The proposed FSS shifts the onset of a grating lobe to the outside of the frequency of interest without compromising the target resonant frequencies. The measured results are shown to be in a very good agreement with the simulated results.

In this article, a via‐based 2.5‐dimensional (2.5D) frequency selective surface (FSS) is proposed to realize a quasi‐elliptical bandpass response with high frequency selectivity. Each FSS element is composed of two parts. Part A is a double‐layer metallic circular patches, which are etched on both sides of a thick substrate and connected by a central big metallic via and several small vias. Part B is a single layer metallic circular patch etched on a thin substrate. The proposed FSS features several transmission/reflection zeros, exhibiting a flat transmission in the passband and fast roll‐off out of band. By investigating the electric field distributions, two paths of electromagnetic wave (EMW) propagation are observed, and the physical mechanism of the transmission/reflection zeros of the FSS is obtained. A prototype of the FSS is fabricated to verify the design, and the measured transmission responses agree with the simulated ones.

This paper presents a novel polarization-insensitive dual-band frequency-selective surface (FSS)-based electromagnetic shield. The miniaturized FSS unit cell consists of a modified Jerusalem crossed loop and a corner-modified square loop. These FSS elements are arranged in a co-planner configuration over a single-layer Rogers 5880 substrate and simultaneously offer effective shielding in the X- and Ku-bands. Moreover, the FSS manifests polarization-independent and angularly stable band-reject filter characteristics over various oblique angles of incidence for both the TE and TM polarizations with virtuous attenuation at both resonances. In addition, the FSS structure is modelled into an equivalent lumped circuit to better analyze the phenomenon of EM wave suppression. A finite prototype of FSS is fabricated and tested. The simulated and measured results are in good agreement, thus making it a potential candidate for RF shielding/isolation applications.

This paper proposes a technique that uses the small-metal width of a frequency-selective surface (FSS) element to suppress the change in beamwidth due to the undesired reflection from other FSSs. FSSs reflect low-level electromagnetic waves that are expected to pass through essentially the FSSs outside of the desired reflection bands, and generate these low level reflections from other FSSs as undesired reflections. Electromagnetic field analysis based on a dual-band antenna structure shows the relationship between the metal width and the reflection coefficient of the FSS element, and the relationship between the metal width and the beamwidth in the desired band and the other band. This paper clarifies that the small-metal width of the FSS element can be used to reduce the change in beamwidth outside the desired band.

An entire domain current expansion set is found for the tripole frequency-selective surface (FSS) using the singularity expansion method (SEM). The SEM analysis is performed on a thin wire model of an isolated FSS element. The SEM natural current modes yield a highly efficient entire domain expansion set for use in a Floquet moment-method analysis of the FSS array. The SEM analysis yields an optimum set of expansions functions without any prior knowledge about the FSS element. >