Resonance method of measurement of input impedance of any broadwall-launched discontinuity in microstrip transmission line

A new microwave method of measuring the input impedance of any broad mall-launched discontinuity in microstrip transmission lines is suggested. In this work the reactance of a metallic post forming a broadwall-launched discontinuity in a microstrip transmission line has been characterized. An analytical expression for reactance of this metallic post has been derived considering it to be an antenna in unbounded space under appropriate boundary conditions, and considering the strip transmission line as an approximation of a planar waveguide. The proposed method is also applicable for measuring impedance of any other broad wall-launched discontinuity in microstrip transmission lines.