Accurate simulation of nonlinear switched capacitors and sampled circuits by harmonic balance and related techniques

The authors show the ability of harmonic balance and related techniques to handle high speed sampled circuits, enabling a complete nonlinear simulation of such circuits. As an example, the simulation of an N-path filter using the harmonic balance method is achieved. A comparison between simulations and measurements of the transfer characteristic is shown and the accuracy and convenience of the proposed method are demonstrated. This technique will allow unification of the simulation tools of nonlinear mixed analogue/digital monolithic circuits to derive the transfer function, conversion noise and saturation characteristics.