A method due to M.I. Herman and I.L. Volakis (IEEE Trans. Ant. and Prop., vol. 36, pp. 664-678, May 1988) is extended to the development of double and triple diffraction coefficients as applied to a pair of impedance wedges. Particular emphasis is given in the evaluation of suitable diffraction coefficients that remain uniform at all reflection and shadow boundaries associated with the multiple wedges. The extended spectral ray method is used along with a more generalized interpretation of the spectral waves.
