Hierarchical singular vector bases for quadrilateral cell MoM applications

Scalar and vector basis functions for modeling edge and corner singularities associated with electromagnetic fields have been developed and used by various authors. A number of singular divergence-conforming bases on triangular elements have been proposed for the solution of integral equations, while bases of the same kind for quadrilateral elements are less common. The present work aims at illustrating the difficulties, the advantages, the accuracy, and the cost of using such bases in Method of Moments solutions of integral equations.