Two-tier L-L de-embedding method for S-parameters measurements of devices mounted in test fixture

By using an indirect method for determining the characteristic impedance of uniform transmission lines embedded in coaxial connectors, a novel two tier L-L de-embedding method is presented. The proposed de-embedding method is suitable for S parameters characterization of GaN HEMTs packaged transistors mounted on a symmetrical and reciprocal test fixture. In addition, the new technique does not presents the limitation exhibited by the Thru-Reflect-Line (TRL) in the low frequency range nor the limitation exhibited by the Thru-Reflect-Match (TRM) in the high frequency range. To validate the new two tier L-L de-embedding method, the S-parameters of a packaged GaN HEMT de-embedded with TRL are used. The good agreement between the DUT S-parameters obtained with both techniques, L-L and the TRL, validates the proposed L-L de-embedding method.