Coaxial to waveguide transitions and device under test characterization by means of inverse techniques

A new two-tier inverse characterization technique for coaxial to waveguide transitions including a device under test (DUT) is presented in this article. The transitions and the DUT are characterized by its scattering parameters, and a cascade procedure is used to compare calculations and measurements during the unterminating procedure. Two different standard types such as short-circuits and thrus are used, and the two transitions jointly with the DUT are simultaneously characterized. Genetic algorithms and a gradient based method have been used for error minimization during the unterminating stage. Results of this two-tier inverse technique are compared to those provided by measurements, simulations, and the three-cavity method, showing that it is possible to properly characterize the coaxial to waveguide transitions and the DUT in a flexible and accurate way. © 2010 Wiley Periodicals, Inc.