General renormalisation transforms for 3-port S parameters

In the measurement of 3-port S parameters in terms of conventional incident and reflected voltage waves, the characteristic impedances of the three measurement ports may not be ideal, owing to discontinuities and other circuit limitations. It is therefore necessary to renormalise the measured values to the ideal characteristic impedances. These procedures are relatively simple to perform when an online computer is employed. The transforms given are general, in that the six impedances involved are all different.