Design Bandpass Frequency Selective Surface Absorber Using LC Resonators

A novel method of designing a frequency selective surface absorber (FSSA) with bandpass characteristic between two neighboring absorption bands is proposed in this letter. This method is implemented by loading lumped resistors and LC resonators in the FSSA structure. An equivalent circuit model together with an analytical design method is developed for further illustration. The performance of the FSSA structure is tested using a free-space measurement system. Experiments show a bandpass response at the center frequency of 6.74 GHz with a fractional bandwidth of 5% and two absorption bands over 3.33-6.26 and 7.09-10.36 GHz with an absorption rate of more than 80%, which indicates a good agreement with the simulation results.