Experimental characterization of S-matrix reconstruction transforms on multiport networks

The characteristics of three existing S-matrix reconstruction transforms on the multiport network characterization are studied for the case of using a single kind of auxiliary terminations. Three unifying properties are discerned and experimentally verified. It is found that the three existing S-matrix transforms prefer auxiliary terminations with small reflection coefficients. When auxiliary terminations with large reflection coefficients are taken, it may encounter numerical difficulty whose destructiveness depends inversely on the power loss of the device under test. These findings may lead more studies on the cause and remedy of the numerical difficulty.