Design of Dual-Polarized Frequency Selective Rasorber With Two Independent Transmission Windows Using Multi-Resonators

In this paper, a dual-polarized frequency selective rasorber (FSR) with two independent transmission windows and three absorption bands is designed and characterized. The proposed FSR is composed of the resistive sheet and the bandpass frequency selective surface (FSS), which are separated by the air spacer. At the top resistive sheet, two concentric modified square loops with different lengths are inserted into the square loop with four lumped-resistor-loaded legs, which provides two independent transmission windows. The bottom bandpass FSS, consisting of the combination of the square slot and the four-leg arrow shaped slot, is adopted to realize the same transmission bands as the upper resistive sheet. Performance of the proposed FSR is investigated via its equivalent circuit model and full-wave simulations. The simulated results exhibit dual-band frequency response, which has two independent transmission windows within three absorption bands. The two pass-bands operate at 8.5GHz and 13GHz with insertion loss of 0.31dB and 0.48dB, respectively. And the three absorption bands are in the range of 4.1GHz-7.5GHz, 9.1GHz-12.3GHz, and 14GHz-19.7GHz, respectively. Also, the band with reflection coefficient lower than -10dB covers from 4.2 GHz to 19.6GHz and the fractional bandwidth is up to 129.4%. Furthermore, prototype of the FSR is fabricated and measured. Good agreements between the measured and the simulated results can be observed.