Novel integral equation formulation for the analysis of capacitive waveguide filters containing dielectric objects

A new integral equation formulation is presented for the analysis of capacitive waveguide components, including metallic and dielectric objects. The technique exploits the symmetry of the structure by formulating a 2D scattering problem with oblique angle of incidence. As a consequence, the analysis of complex waveguide capacitive devices results to be very efficient, as compared to other 3D numerical techniques. As practical application, the paper proposes a low-pass filter loaded with dielectric and magnetic materials. Results are validated with commercial full-wave simulators showing the validity and accuracy of the novel integral equation technique.