Multiband FSS Analysis and Synthesis Based on Parallel Non Coupled Metallic Strips Using WCIP Method

Henri Baudrand,Ibtissem Adoui,Awatef Djouimaa,Karima Bencherif,Mohammed Titaouine,Thayuan Rolim De Sousa,Raouia Saidi,Alfredo Gomes Neto

doi:10.1590/2179-10742018v17i41264

Abstract

A novel parallel coupled Metallic strips frequency selective surface (FSS) is presented. The design is based on a filter composed of horizontal and vertical metallic strips. The structure has the advantage of simplicity and gives multi resonant frequencies easily controlled by a simple variation in the strips length. The proposed FSS rejects frequencies at 7GHz, 9.4GHz with bandwidths of 0.646GHz, 0.793GHz respectively when the structure is excited with an x polarized plane wave, and two frequencies at 9.1GHz and 11.2 GHz with bandwidth of 280.3MHz, 63MHz respectively when the structure is excited with a y polarized plane wave. To suppress frequencies ideal diode on reverse bias are inserted. The simulated results obtained using WCIP (Wave Concept Iterative Method) are compared to the COMSOL Multiphysics 4.3b software results, and measurements, a good agreement is observed. Then, an FSS synthesis approach based on non coupled parallel metallic strips is presented. It allows the synthesis of FSS for resonant frequencies ranging from 4.5GHz and 12.25 GHz for strips lengths inversely varying from 5mm to 19mm. To validate the synthesis approach, measured resonant frequencies are used as desired resonant frequencies to determine the metallic strips lengths. As a result the metallic strips FSS dimensions are extracted. Then the WCIP method is used to characterize the synthesized FSS. Three FSSs are synthesized based on the fabricated FSS and good agreement between measurements and synthesized FSSs results is recorded.

Highlights

Frequency selective surface (FSS) is a 2D-periodic planar structure consisting of one or more patches or slots etched on a dielectric substrate to operate as band stop or band pass filters respectively [1,2,3]
The transmission coefficients S12 of the parallel metallic strips FSS of Fig. 2 when the structure is excited by an x and y polarized normal plane waves are shown in Figs. 3.a and 3.b respectively
10.7GHz with bandwidths of 1.446GHz, 0.93 GHz and 27.6MHz respectively when the structure is excited with a y polarized plane wave

Summary

Introduction

Frequency selective surface (FSS) is a 2D-periodic planar structure consisting of one or more patches or slots etched on a dielectric substrate to operate as band stop or band pass filters respectively [1,2,3]. In this paper the analysis of simple FSS based on parallel non coupled metallic strips using WCIP (Wave Concept Iterative Method) is presented. For a priory choice of the FSS resonant frequencies number and values based on the available substrates, a synthesis approach based on non coupled parallel metallic strips and a ring is introduced. First the characteristic strip/ring curve is determined using the WCIP method for strip lengths ranging from 6mm to 19mm and for the ring outer circumference varying from 34mm to 58mm. To validate the presented synthesis approach, measured resonant frequencies of three manufactured FSSs are input to the proposed approach as desired resonant frequencies to extract the necessary metallic strips lengths. The presented synthesis approach allows the determination of an equivalent metallic strips based FSS for complexes FSS structures. Good agreement between measurements and WCIP results obtained for the synthesized FSSs is observed

Methods

Results

Conclusion