Design of a PIN Diode-Based Reconfigurable Frequency Selective Surface

This paper presents a reconfigurable (active) frequency selective surface allowing three transmission/reflection frequency bands to be switched to operate in reverse. The proposed FSS unit cell consists of F-type conductors on both surfaces of the dielectric substrate and a square loop conductor on the upper surface. The reconfigurability is achieved using PIN diodes. When the diodes are switched from the OFF to the ON state, two stopbands operating at 5.2 and 5.9 GHz become passbands, and the passband at 4 GHz turns into a stopband. The proposed structure with multi-band characteristics provides stable performance at incident angles up to 60 degrees with TE and TM polarizations under the OFF and ON states of PIN diodes. The performance of the design has been examined using an equivalent circuit model and simulated regarding angular stability and variations in resonant frequency using CST Microwave Studio.