The goal of the investigation is to develop the preliminary analysis and computer codes for studying phased arrays of microstrip elements on inhomogeneous substrates. The analysis is based on an application of the equivalence principle transforming a nonplanar problem into one with parallel-plate regions which can be solved using a combination of the Green's function/moment method approach and mode matching techniques. The method seeks to calculate for a particular scan the element input impedance and the expansion mode coefficients defining the current distribution. The effects of the substrate inhomogeneity on the array scan performance are considered and the results are compared to those of the homogeneous microstrip phased array.
