Active frequency selective surface with multiple switchable functions and angular stability

An active frequency selective surface (AFSS) with multiple switchable functions and angular stability is proposed, which can achieve absorption, reflection, and transmission functions through PIN diodes and resistors. The design consists of three layers, including the first layer consisting of an absorption and transmission reconfigurable surface with a circular ring structure, the middle air layer, and the last layer consisting of a transmission and reflection reconfigurable surface with interdigital resonator. In comparison to previously reported AFSS, the proposed surface offers three different working modes and achieves broadband properties and wide-angle stability.