Quasi-static analysis of a microstrip via through a hole in a ground plane

摘要

The equivalent circuit of a via connecting two semi-infinitely long transmission lines through a circular hole in a ground plane is found. The pi -type equivalent circuit consists of two excess capacitances and an excess inductance. These are quasistatic quantities and thus are computed statically by the method of moments from integral equations. The integral equations are established by introducing a sheet of magnetic current in the electrostatic case and a layer of magnetic charge in the magnetostatic case. Parametric plots of the excess capacitances, the excess inductance, and the characteristic admittance of the via are given.