S-parameter characterisation of coaxial to microstrip transition

A coaxial to microstrip transition is characterised in terms of S-parameters, thus enabling a simple correction to be applied to measurements made on devices in microstrip. The transition, the model of which includes a fixed length of the microstrip line, is represented by S-parameters which are simple linear functions of frequency over the band 2¿¿4 GHz. A simple computer program may be used to de-embed a device in the microstrip, or to calculate the expected values of the S-parameters at the inputs to the coaxial transitions when a known device is inserted into the microstrip line.