Cut-Off Wavenumbers of Polygonal Cross Section Waveguides

The choice of basis functions is a key-point in Galerkin´s method. Taking into account the edge behaviour of the fields can greatly improve the effectiveness of the method, especially when dealing with conducting structures. Another issue is related to the impedance matrix computation, which can be cumbersome when resorting to the spectral domain. The aim of this letter is the analysis of arbitrary polygonal cross section waveguides with a technique addressing both the aforementioned issues. The reported numerical results show that high accuracy can be obtained quickly and with few basis functions.