Uni-directional basis functions based on endfire virtual sources for sparse matrix generation

Sparse impedance matrices can be produced by applying directive basis functions, which radiate collimated beams externally and internally in relation with the surface. To decrease interactions within the body, uni-directional basis function has been recently suggested. In this study, virtual electric currents are applied only in real coordinates within the scatterer, characteristically in the configuration of endfire arrays. Two alternatives for testing functions are also discussed. The first is point matching, which presents a well defined region of illumination with sidelobes. The second is suggested to decrease these sidelobes, where the produced fields by the basis functions are utilized as the testing functions.