A Switchable Single/Double-Band Active Frequency Selective Surface

This paper presents a switchable single/doubleband active frequency selective surface (AFSS). By controlling the DC bias state of the PIN diodes in the interleaved AFSS units, flexible control over three distinct frequency responses is achieved, with a simple feeding structure. States 1 and 2 exhibit single-band frequency responses with resonances at 8.97 GHz and 10.75 GHz, respectively, with insertion losses of 0.66 dB and 0.63 dB. State 3 demonstrates a dual-band frequency response with resonances at 9.01 GHz and 10.70 GHz, with insertion losses of 0.66 dB and 0.60 dB, respectively. All states of the AFSS exhibit polarization insensitivity and good angular stability. This structure provides a novel design approach for active frequency selective surfaces.