Efficient computation of the reaction terms to fill the interaction matrix in the Characteristic Basis Function Method (CBFM)

A technique to speed up the evaluation of the reduced matrix terms in the CBFM, for scatterers modeled by using a generically-shaped NURBS surface, has been presented in this work. The PO-based CBFs are computed by considering linear variations of both the amplitude and the phase of the PO integrand, defined over triangular basis functions in the NURBS parametric domain.