A three-port vector network analyzer - measurement system, calibration and results

In this paper a practical three-port vector network analyzer (TVNA) measurement system with its calibration procedures, and results are presented. With this TVNA, the three-port device scattering matrix can be directly measured by using a test fixture or a probe station. It can then reduce the repeatability problem occurred in the use of conventional two-port vector network analyzer by connecting and disconnecting matched load at the different ports of a three-port device. The three-port TRL and LRM calibration procedures are developed and verified with the coaxial circuits. In addition, a three-port SOLR calibration procedure is developed for on-wafer measurement of a three-port MMIC with three orthogonal-oriented pads.