A Polarization-Independent Wideband Switchable Rasorber With High Roll-Off Characteristics Utilizing Third-Order Switchable FSS

In recent years, switchable frequency selective rasorbers (FSRs) have been extensively studied due to their in-band shielding ability. However, it is difficult to achieve dual-polarized switchable FSR with wide passband and excellent roll-off characteristics simultaneously. In this letter, a polarization-independent wideband switchable FSR with high roll-off characteristics is proposed. The FSR is composed of a three-layer architecture with a non-switchable impedance layer, a switchable impedance layer and a switchable frequency selective surface (FSS). A switchable FSS with third-order response is utilized to achieve low profile, wideband transmission and high roll-off characteristics. Meanwhile, a wide low reflection band is achieved with the assistance of two impedance layers. Under each polarization, the device can be independently switched between rasorber and absorber modes. Finally, a prototype is manufactured and measured to demonstrate the viability of the proposed design. Compared with the existing counterparts, the proposed dual-polarized switchable FSR exhibits excellent performance in terms of wideband transmission, high roll-off characteristics and broadband absorption.