Switchable Ultra-Wide Absorber/Absorptive Frequency Selective Reflector Using Ideal PIN Diode

A switchable absorber/absorptive frequency selective reflector (AFSR) is proposed in this paper. This structure is switchable by enabling an ideal PIN diode or not. When the PIN diode is enabled, the structure works as an absorber with an ultra-wide absorption band. And the structure works as an AFSR when the PIN diode is disenabled. Simulated results show that the achieved absorber has a wide absorption band (|S11| ≤ -10dB) with a fractional bandwidth of 150.3%, which is from 1.92 GHz to 13.42 GHz. The realized AFSR has two absorption bands, and one reflection band (|S11 ≥ -1dB). The lower absorption band is from 1.98 GHz to 4.86 GHz (84.2%) and the upper absorption band is from 8.37 GHz to 13.37 GHz (50%). The simulated reflection band is from 4.86 GHz to 8.37 GHz (46%). The relative thickness of the proposed structure is 0.128.