Polarization-Insensitive Single- and Broadband Switchable Absorber/Reflector and Its Realization Using a Novel Biasing Technique

In this communication, a switchable absorber/reflector based on active frequency-selective surface (AFSS) has been presented for single- as well as broadband applications. The FSS comprises periodic patterns of square loops connected among themselves through p-i-n diodes, which exhibit switchable performances. The novelty of the proposed design lies in its symmetric configuration and biasing network, which makes the structure polarization insensitive unlike the earlier reported AFSSs. A single-band switchable absorber/reflector has initially been realized, which is characterized through an equivalent circuit model to derive the circuit parameters. Later, surface-mount resistors have been implemented in the design to realize a wideband switchable absorber/reflector aimed for C-band applications. Both the structures have used a novel biasing methodology to provide the bias voltage to semiconductor switches without disturbing the original resonance pattern. Furthermore, the fabricated samples, while measuring in an anechoic chamber, show good agreement with the simulated responses under normal incidence as well as for different polarization angles.