Electrodynamics boundary problem solution for sectoral coaxial ridged waveguides by integral equation technique

Abstract

The electrodynamics eigenmodes boundary problem for sectoral coaxial single-ridged waveguides is solved by the integral equation technique utilizing the introduced system of orthogonal basis functions, which correctly take into account the singular field behavior at the ridge. The formulas obtained allow to compute cutoff wave numbers and electric and magnetic fields distributions of TE and TM modes in the presence of the ridge either on the outer or on the inner wall of the waveguide. The analysis of the dependence of cutoff wave numbers convergence on the type and the amount of basis functions and partial modes has been carried out. It is shown that for obtaining 0.1% residual error it is necessary to utilize in two times more unorthogonal basis functions, which correctly take into account singularity at the ridge, than introduced orthogonal basis functions, which correctly take into account singularity at the ridge, and in five times more orthogonal trigonometric basis functions, which don’t take into account singularity at the ridge. Besides the computing time increases in 4 and in 20 times, respectively.