Higher‐order hierarchical basis functions with improved orthogonality properties for moment‐method modeling of metallic and dielectric microwave structures

Three classes of higher‐order hierarchical basis functions, constructed from standard orthogonal polynomials, are proposed and evaluated for the modeling of combined metallic and dielectric microwave structures. The reduction of the condition number of moment‐method matrices is several orders of magnitude, as compared to the technique using regular polynomial basis functions.