Higher Order Vector Bases for the Method of Moments Analysis of a Class of Waveguide and Dielectric Resonator Filters Involving Curved Boundaries

A combined electric field integral (EFIE) Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation technique is presented, in which divergence-conforming higher order vector basis functions are applied. Curved surfaces are modeled using curvilinear triangles in order to minimize geometrical modeling inaccuracies. Conforming vector bases provide appropriate continuity at material interfaces and allow for imposing boundary conditions on unknown fields or currents. The advantage of the proposed method against existing approaches is its higher efficiency and flexibility. The versatility and accuracy of the method are verified at typical filter examples by comparison with reference results.