Active Frequency Selective Surface with Simultaneous Absorption/Transmission Mode Switching and Frequency Tuning Characteristic

Abstract

A novel active frequency selective surface (AFSS) exhibiting a multifunctional characteristic, switching and frequency tuning, is present in this paper. The proposed structure is made up of periodic metallic patterns printed on the opposite sides of a dielectric substrate. Two different active components (varactors and PIN diodes) are mounted on the top and bottom layers, respectively. The switching characteristics between transmission and absorption modes can be obtained by controlling the biasing condition (OFF/ON state) of the PIN diodes on the bottom layer, where both modes having frequency tuning capability by regulating the voltage of varactor diodes on the top layer. Besides, full-wave simulation has been investigated to study the characteristic of the proposed designed. The structure has been fabricated to verify with the simulation results. In transmission mode, the proposed AFSS realizes tunable bandpass responses from 3.70 to 4.27 GHz with 1.96–4.30 dB insertion loss. In absorption mode, the absorption frequency can be tuned from 4.28 to 5.12 GHz with 78.77−90.78% absorptivity.