An active millimeter load-pull measurement system using two six-port reflectometers operating in the W-frequency band

An active load-pull measurement system using two six-port reflectometers operating in the W-frequency band is demonstrated. Ninety loads over the whole Smith chart have been synthesized and measured by both reflectometers. The maximum deviation between both measurement data is 0.02 for the magnitude and 3° for the phase of the reflection coefficient of the 90 loads. The constant power gain circles of a PHEMT operating at 89 GHz are shown and compared with those calculated from its S_ij scattering parameters. The deviation between the radii of circles is less than 0.03.