Multimode Network Representation of a Radiating Array of Thick Parallel Plates

In this paper, we describe a novel multimode network representation for the analysis of radiating array of thick parallel plates. Due to the periodicity and infinite transverse extent, only one period of the structure needs to be studied. The key step is then the derivation of the equivalent network representation for the transition from a free-space region limited by phase-shift walls to a parallel plate waveguide. The network formulation leads to an integral equation that is then solved with the method of moments. Once this key building block is obtained, it allows for the study of a wide class of scattering problems such as corrugated surfaces, single or cascaded thick gratings. Comparison with published measured data are also presented indicating that the method proposed is indeed very accurate.