Enhanced PHD model extraction by improving harmonic response superposition during extraction

A Poly-Harmonic Distortion (PHD) model extraction procedure is proposed to improve the model accuracy for unmatched, broadband RF transistors by minimizing multi-harmonic signal reflections within the measurement system. As a result, the fictitious need for higher-order models is avoided by minimizing the order of the nonlinear measurement system used to extract the model. Under strongly nonlinear conditions the accuracy of the PHD model is improved by 5dB, in terms of Normalized Mean-Squared Error (NMSE), averaging less than 1% time-domain output power error.