Recovering Suppressed Resonance Frequency by Bias Lines in Reconfigurable FSS

Alfredo Gomes Neto,Laryssa Maria De Sousa Duarte,Jefferson Costa E Silva,Gabryel Jerônimo De Morais,Diego Cassio Garcia Fernandes

doi:10.1590/2179-10742021v20i31193

Abstract

In reconfigurable frequency selective surface, FSS, bias lines can suppress a resonant frequency. This is a disadvantage, as it reduces a FSS potential application. In this paper, a procedure to recover the suppressed resonant frequency is described. A FSS based on four arms star geometry is considered and its reconfigurability is achieved by the use of varactors, for which bias lines suppress the x polarization resonance. So, dipoles are added to the unit cell geometry recovering this resonance. In order to validate the proposed procedure, a reconfigurable FSS using the varactor SMV1231 (0. 466 pF ≤ Cv < 2. 35 pF) was fabricated and characterized. Numerical and measured results shown a good agreement, confirming that the FSS reconfigurability is preserved and the suppressed resonance recovered.

Highlights

Frequency selective surfaces, FSS, have attracted the attention of several research groups, both for simplicity of manufacture and for the diversity of applications [1]—[3]
In order to recover the suppressed resonance, this paper describes the inclusion of dipoles along the direction, obtaining the respective resonance, without altering the reconfigurable behavior in the polarization
As bias lines in reconfigurable FSS can suppress a resonant frequency, a procedure to recover this suppressed resonance was described in this paper

Summary

INTRODUCTION

FSS, have attracted the attention of several research groups, both for simplicity of manufacture and for the diversity of applications [1]—[3]. In the discrete electronic tuning, when a limited number of the FSS frequency responses is required, normally PIN diodes or MEMS switches are used. In the reconfigurable FSS, in addition to the insertion of the active component, it is necessary to include the bias lines, as depicted, for the four arms star geometry [14]. Aiming to reinforce the x polarization resonance, a second dipole is inserted between the four arms stars. This second dipole is dislocated to avoid a coupling with the bias lines. After this Introduction, four arms star and dipole geometry are described, which included the varactor model.

Dipole

Four arms star geometry

Varactor model

CONCLUSIONS