A Dual‐Polarized Frequency Selective Rasorber With Wide Transmission Band

In this paper, a novel and simple dual‐polarized frequency‐selective rasorber (FSR) which has a wide absorption band including a wide transmission band was presented. Detailed equivalent circuit was derived to accurately predict the frequency responses of the structure. Based on reasonable equivalent analysis of a traditional metal grid structure, a modified structure with improved performance was proposed. The structure consists of a lossy frequency‐selective surface (FSS) constructed with metal rings connected by center loaded strips as the top layer, and a broadband transmission FSS at the bottom, while the two layers are separated by air. To validate our proposal, a prototype was fabricated and measured. The measured results are in good agreements with simulations under normal incidence, which indicates a broad absorption bandwidth of 80% that from 3.40 to 8.16 GHz; in the meantime, a wide transmission band with an insertion loss of less than −1.25 dB is ranging from 9.03 to 12.01 GHz. It should be pointed out that, the reflection from the whole structure in the operation band can be kept below −10 dB from 4.15 to 11.87 GHz.