Efficient per-nonlinearity distortion analysis for analog and RF circuits

An efficient distortion analysis methodology is presented for analog and RF circuits that utilizes linear-centric circuit models to generate individual distortion contributions due to each nonlinear component in a circuit. The per-nonlinearity distortion results are obtained via a straightforward post-simulation step that is simpler and more efficient than the Volterra series-based approaches and does not require high-order device-model derivatives. For this reason, the order of analysis can be significantly higher than that for a Volterra series-based implementation while fully accounting for all distortion effects using most existing device models. Moreover, the proposed methodology can also analyze per-nonlinearity distortion for active switching mixers and switch capacitor circuits when they are modeled as periodically time-varying weakly nonlinear systems. The proposed methodology provides important design insights regarding the relationships between design parameters and circuit linearity, hence, the overall system performance. Circuit examples are used to demonstrate the efficacy of the proposed approach, and interesting insights are observed for RF switching mixers in particular.