Design Dual-Polarization Frequency Selective Rasorber Using Split Ring Resonators

A novel dual-polarization frequency selective rasorber with one transmission band and two absorbing bands is proposed in this paper. The structure is composed of a lossless frequency selective surface layer and a resistive layer. The resistive layer is a combination of split ring resonators and Jerusalem crosses. The frequency selective surface layer is a combination of grids and square rings. Split ring resonators are used to generate parallel resonances in this paper. When the parallel resonant frequency of the split ring resonators and that of the frequency selective surface layer are the same, a passband is obtained. Split ring resonators, Jerusalem crosses, and lumped resistors are used to create the absorbing bands. When surface current flows through two different paths on the split ring resonator, absorbing bands are obtained on each side of the passband. A frequency selective rasorber prototype is fabricated and measured to validate our design. The results show that the center frequency of the passband is 5.74 GHz, with an insertion loss of 0.25 dB. The lower and higher absorption bandwidths with absorption coefficient higher than 80% range from 1.92 to 3.73 GHz and from 7.41 to 9.34 GHz, respectively, and the reflection band with reflection coefficient less than -10 dB ranges from 1.96 to 9.32 GHz.