Frequency selective rasorber with a high-gain passband

A new frequency-selective rasorber which shows a broadband high-gain passband is designed in this paper. The high-gain passband is achieved by the bottom 1-bit transmissive lens under x-polarized incidence. According to the simulation results, it can be observed that the antenna gain has increased by 7dBcompared with the feed antenna from 9.5GHz to 11.7GHz. Furthermore, the backward RCS is reduced by 10dB from 2.8GHz to 20GHz and the relative bandwidth can reach 151%.