Multiharmonic generators for relative phase calibration of nonlinear network analyzers

Multiharmonic generators are of interest for determining coupler phase disp ersion of nonlinear network analyzers inherently dealing with nonsinusoidal waveforms for RF current-voltage (I-V) measurements. Supported by simple w aveform analysis, two on-wafer devices are experimentally evaluated: a sing le diode and a nonlinear transmission line (NLTL), The investigation uses a n active harmonic load-pull system with 2 GHz fundamental frequency, It tur ns out that the NLTL is well suited as reference generator. We present meas urement examples of phase dispersion for different directional couplers up to 18 GHz and the application to RF I-V waveforms of a 1-W power HBT with h armonic load tuning.