2-bit switchable active frequency selective surface

An active frequency selective surface (AFSS) with switch function is proposed in this paper. Double coupled metallic meandered structures on one layer substrate loaded PIN diodes and biasing lines are designed carefully to realize four switchable states (2-bit): both TE polarization & TM polarization band-pass filter for code 00; TE band-pass filter for code 01; TM band-pass filter for code 10; both TE & TM reject for code 11. The equivalent circuit model (ECM) is given to understand better in physical view and biasing network topology is explained how to realize multi-state switching through biasing voltage control. The transmission coefficient of 2-bit states are shown and the angle-stability is analyzed through the simulation results.