Multiband artificial magnetic conductors using stacked microstrip patch layers

A two-dimensional microstrip patch array with a conducting via connecting the center of each patch to ground has been proposed for an artificial magnetic conductor (AMC). On the other hand, a microstrip patch array without vias has been shown to produce an AMC. This paper analyzes AMC structures with and without vias by using an effective medium model and finite difference time domain (FDTD) full-wave analysis method. The difference between the properties of these AMC structures is investigated in detail. Based on the results, we devised a multiband AMC structure having stacked microstrip patch layers. FDTD calculations and measurements were performed to demonstrate the effectiveness of the multiband AMC.