Modal analysis of rectangular waveguide phased arrays

A modal technique for the analysis of infinite waveguide phased arrays is presented. Each network discontinuity, such as waveguide-free space junction, multiple dielectric layers, inductive/capacitive irises, in the unit cell is represented by its generalised scattering matrix (GSM). The GSM of each obstacle is obtained by the mode matching method. All the GSMs are cascaded together to provide a full description of the waveguide element performance in an array environment. The modal method is accurate and fast, requiring only one or two seconds on a PC for a single frequency-scan analysis. It is used in the optimization of broadband wide scan rectangular waveguide phased arrays.