Multiple diffractions among polygonal impedance cylinders

Rigorous diffraction coefficients are derived for the doubly and triply diffracted fields among impedance wedges of arbitrary orientation not sharing a common surface. The analysis is an extension of previous work applicable to impedance wedges on a common surface. The derived diffraction coefficients are shown to remain valid at the transition regions. Similar diffraction coefficients are also given for all triply diffracted fields between two polygonal impedance cylinders; these contain the necessary surface-wave contributions in a uniform manner. When these coefficient are coupled with those already derived for the multiply diffracted fields on a single cylinder, the complete analysis of the doubly and triply diffracted fields among two or more polygonal cylinders is possible. To verify the uniformity and validity of the total field at the transition regions, some scattering patterns for certain simple geometries are presented