A Frequency Selective Rasorber with Ultra-Wideband Switchable Transmission/Reflection and Two-Sided Absorption
Liangzhen Lin,
Jianqiong Zhang,
Liangzhu Li,
Xiang-Qiang Li and
Qingfeng Wang
A novel switchable frequency selective rasorber (FSR), featuring dual wideband absorption bands and an ultra-wide passband that can be switched to a reflective band, is proposed in this work. This design incorporates a lossy layer and a three-layer reconfigurable frequency selective surface (FSS). An ultra-wideband transmission can be achieved through the lossy layer by means of circular spiral resonators. The switchable function is utilized by a reconfigurable FSS with PIN diodes. Simulation results confirm the FSR's broad absorption from 1.44 to 2.39 GHz (49.6%) and from 5.45 to 6.64 GHz (19.7%). It also achieves an extensive passband with a 1-dB bandwidth of 47.78% (3.17~5.16 GHz) in the absorption-transmission-absorption (A-T-A) mode, which is the widest transmission band in existing designs. The passband is converted into a reflection band in the absorption-reflection-absorption (A-R-A) mode, showcasing the FSR's switchable characteristics. To validate these simulation outcomes, a prototype measuring 300 x 300 mm is constructed and measured.
