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. Key Points A miniaturized‐element frequency selective surface is adopted to construct frequency selective rasorber with wide transmission band The authors elaborate the working mechanism and design criteria of frequency selective rasorber with broad transmission band in detail This work has a good merit of fewer lumped resistors used in the whole design compared to others, which is more practical in engineering