This letter presents a frequency selective absorber (FSR) with a passband and two wide absorption bands. The structure is composed of a resistive layer and a bandpass frequency selective surface (FSS) layer. The resistive layer is a combination of metal lines with loaded resistors and rectangular spiral resonators, which generate parallel resonances. Square slots are designed in the bandpass FSS to produce parallel resonance inside the passband and perform as a metal plane outside the passband. A nearly transparent window can be obtained by adjusting the parallel resonant frequencies of two layers to be consistent. The simulation results show that the 3 dB transmission band ranges from 6.5 to 7.76 GHz, and the minimum insertion loss is 0.05 dB at 7.09 GHz. The dual-polarized FSR presents stable operating characteristics and realizes two absorption bands on both sides of the passband, and the fractional bandwidth of the reflection coefficient lower than −10 dB is up to 127%, which ranges from 2.69 to 12.04 GHz. In addition, the FSR is manufactured and measured, and the measurement results are consistent with the simulation results.

中文翻译：

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具有矩形螺旋谐振器的宽带选频吸收器


这封信介绍了一种具有通带和两个宽吸收带的频率选择吸收器（FSR）。该结构由电阻层和带通频率选择表面（FSS）层组成。电阻层是带有负载电阻的金属线和矩形螺旋谐振器的组合，可产生并联谐振。带通FSS中设计有方形槽，可在通带内产生并联谐振，并在通带外充当金属平面。通过调整两层的平行谐振频率一致，可以获得近乎透明的窗口。仿真结果表明，3 dB传输频段范围为6.5~7.76 GHz，7.09 GHz处插入损耗最小为0.05 dB。双偏振FSR表现出稳定的工作特性，并在通带两侧实现了两个吸收带，反射系数低于-10 dB的分数带宽高达127%，范围为2.69至12.04 GHz。另外，制作并测量了FSR，测量结果与仿真结果一致。