Broadband Polarization-insensitive Tunable Absorber Using Active Frequency Selective Surface

In this letter, a broadband polarization-independent tunable absorber is proposed based on active frequency selective surface (AFSS). The AFSS consists of periodic patterns of four-patch array with four p-i-n diodes loaded among them, and a simple bias network is designed behind the ground plane through metalized via holes, which can effectively reduce the influence on the absorbing performance. B...