New algorithm based on BEM-Pade approximants to an efficient treatment of waveguide discontinuities

This paper presents a new, fast, and accurate algorithm based upon Pade approximants in the Boundary Element Method (BEM) to design waveguide discontinuities. The solutions of Helmholtz equation using Galerkin Method and BEM are obtained through non-linear eigenvalues problems. In this algorithm, the double scalar and vector Green's function are expanded in powers of the frequency and recast in a rational form. The asymptotic kernel (wavenumber) function built permits a perfect representation of the impedance operator. The wavenumbers are accurate and the research is computationally affordable.