A Stable Frequency Selective Rasorber with Two Transmission Band

A stable frequency selective rasorber (FSR) with two absorption bands and two transmission bands is proposed in this paper. In our design, the structure is composed of a lossy layer and a lossless layer. These two layers are isolated by air. The lossy layer is composed of a metal loop and resistors loaded on it. The lossless layer is composed of a band-pass frequency selective surface (FSS) of two square rings, which realizes the two-band transmission response. In this paper, the S-parameters, absorption and transmission curves, and the polarization stability of the structure are simulated and analyzed. The simulation results show that the structure has higher absorption and transmission. The absorption band is $2.4 \text{GHz}-3.0 \text{GHz}$ and $5.8 \text{GHz}-8.2 \text{GHz}$. The transmission band is $4.1 \text{GHz}-4.9 \text{GHz}$ and $9.2 \text{GHz}-9.6 \text{GHz}$. This structure also has good polarization stability.