Application of the unequal two-tone method for AM-AM and AM-PM characterization of MMIC power amplifiers

The unequal 2-tone method is reviewed and applied to K-Band MMIC power amplifiers. The technique can be used to simultaneously characterize AM-AM, AM-PM conversion coefficients and insertion phase under drive as well as estimate third order intermodulation ratio and intercept point. The method may be applied by making a simple modification to existing equal 2-tone or mixer test systems. Test results are presented in-fixture for a 1 W power amplifier MMIC at 22 GHz and on-wafer in a production environment for two 20 GHz power amplifier MMIC.