Transmission response measurements of frequency-translating devices using a vector network analyzer

A new method for accurately determining the transmission response of frequency-translating devices (FTDs) is presented. The absolute amplitude and phase of the FTD under test is obtained using a vector network analyzer (VNA) and two test FTDs, where one FTD must have reciprocal frequency response characteristics. The characterization of single-sideband (SSB) FTDs is obtained in a straightforward manner by combining data from three VNA two-port swept measurements. The characterization of double-sideband (DSB) FTDs can be performed in the same manner as for SSB FTDs, or, more accurately, by combining data from six two-port swept baseband measurements. A complete analysis of the characterization method using low-pass equivalent (LPE) signals and systems is presented, along with the development of the appropriate data reduction procedures needed to arrive at the de-embedded LPE FTD transmission responses. The validation and accuracy of the method is demonstrated with results for both SSB and DSB FTDs operating at 20 GHz.