Approximation of a rectangular via hole from a cylindrical cross section using the fundamental TM mode

Abstract

In this paper, is presented how to calculate the dimensions of a via hole with rectangular cross section from the dimensions of a cylindrical via hole. In the approach presented herein, it is only considered the fundamental TM mode to calculate the propagation constant. This one is determined for a frequency range from 0 to 20 GHz, for both structures. It is shown that the values of constant propagations for a cylindrical structure are different to a rectangular structure when the relationship between the dimensions of the waveguide and the via hole is lower than 200.