Polarization-Insentive Active Frequency Selective Surface And Its Spectrum Conversion

In this work, a switchable polarization-insensitive active frequency-selective surface (AFSS) is proposed, exhibiting both absorption and reflection functionalities. The proposed structure consist of a top AFSS layer, an upper dielectric layer, a metal ground, a lower dielectric layer, and a simple bias network on the bottom to reduce interference. The symmetry of the structure results in polarization-insensitive performance of the metasurface. By introducing resistors in parallel with the diodes to broaden the operational bandwidth, dynamic switching between absorption "0" and reflection "1" effects is achieved by varying the bias voltage applied to the pin diodes. Through dynamic encoding of "0" and "1" states, the AFSS is capable of realizing spectrum conversion for predefined signals.