A Dual-Band Composite Frequency Selective Rasorber With Broadband Absorption Performance

In this letter, a dual-band frequency selective rasorber (FSR) is proposed based on a composite absorption structure. The FSR is a three-tier structure composed of lossy layer I, lossy layer II, and a dual-band frequency selective surface (FSS). The lossy layer I is composed of a lossy cross-shaped structure in which, dual-passband resonators are added and constructed by parallel interdigital capacitors and meandering strip inductors. The lossy layer II is composed of a hybrid circular strip resonator loaded with lossy elements. FSS is implemented in two Jerusalem slots. By combining the lossy layers I and II as a composite lossy structure, the absorption bands of lossy layers I and II are successfully connected in the frequency response, and the bandwidth of S
₁₁
under −10 dB is extended from 3.1 to 20.6 GHz. The proposed FSR integrate dual-band, dual-polarized, and broadband absorption performance simultaneously. Finally, a prototype of the composite FSR is fabricated to validate the simulated results.