Equivalent circuit method for analyzing high impedance surface based microwave absorbing structure

This paper introduced a kind of High Impedance Frequency Selective Surface with double dielectric slaps. The performance of this structure is great and absorbing characteristic of S11 was verified from 7 to 16.5GHz under -10dB. Its thickness is only 3.9mm. Then, we proposed a new equivalent circuit structure and analyzed the absorbing material with this Equivalent Circuit Method(ECM). The analyzing results were compared with the simulated ones, which proved the accuracy of the simulated results and the validity of the Equivalent Circuit Method. Then, the paper put forward several kinds of FSS units and verified them with the equivalent circuit method. We explored the influences of different shapes on the equivalent circuit and S11 curves. So, two ways were proposed to increase the bandwidth and wave absorption performance in the low frequency. It once again confirmed that the equivalent circuit method has the applicability for analyzing the structure.