Equivalent circuit analysis for double layer patch type AMC in consideration of mutual coupling between layers

This paper describes the equivalent circuit analysis of a double layer AMC (Artificial Magnetic Conductor) in consideration of mutual coupling between layers. The AMC with double layer patch type FSS (Frequency Selective Surface) is focused. This paper treats two type double layer structures. The one is stacked structure, and the other is alternated structure. It was shown that the calculated results by using the equivalent circuit well agreed with the results of the FDTD analysis. In addition, it was clarified that the stacked and alternated structures cause the common mode and the differential mode coupling, respectively. Moreover, it was shown that the miniaturization of the AMC is designed by setting the distance between the layers of double layer FSS as thin as possible.