Active Frequency Selective Surface Absorber With Point-to-Point Biasing Control System

A frequency selective surface (FSS) absorber with a biasing control system is presented in this letter. The absorber consists of the top-layer FSS structure, the bottom-layer metal sheet, and an air spacer in between. The biasing circuit is controlled by a single-chip microcomputer with constant current outputs and each output port is connected to one p-i-n diode, which is employed to realize different absorption bands by controlling the induced current distribution. Both simulated and measured results demonstrate that fast switching function can be realized within certain frequency ranges (3.62–5.35 GHz and 7.92–9.27 GHz) with the absorption depth below −10 dB.