Intermodulation distortion characteristics of RF MOSFETs

Intermodulation distortion (IMD) prediction capabilities of a recently developed MOSFET model are assessed by analysing the first to fifth order derivatives of the model, extracted from DC and small-signal s-parameter data. The computed main characteristics and the associated derivatives are shown to be continuous over the entire bias plane, including below threshold. Results of two-tone tests for the case of a MOSFET process are presented. Weak-signal, third and fifth intermodulation distortion products are successfully correlated with the derivatives of the model for a range of bias points, and this analysis is extended to more realistic WCDMA signals.