Adaptive generation of excitation-independent characteristic basis functions

© 2017 IEEE. The Characteristic Basis Function Method (CBFM) has been widely used in recent years to solve a variety of electromagnetic scattering problems because it offers a way to direct-solve large problems without the use of iteration, enabling it to not only handle multiple excitation (r.h.s.) problems in an efficient manner, but to also bypass the issues of ill-conditioning as well as generation of preconditioners. In the past, the choice of number of plane wave excitations used to generate the excitation-independent CBFs have been made empirically, on an ad hoc basis, rather than systematically. This paper presents an adaptive approach for generating the CBFs, which provides a systematic way to determine of the number of plane waves needed for CBF generation, and this in turn renders the CBFM computationally efficient