Frequency-domain analysis of nonlinear circuits driven by multi-tone signals

An efficient algorithm is given for calculating the steady-state response of a nonlinear circuit driven by multi-tone signals, possibly made up of incommensurable frequencies
\omega_{1}, \omega_{2}, \cdots , \omega_{p}
. The algorithm is particularly useful when the steady-state response is not periodic, thereby invalidating most existing methods. The algorithm is much more efficient than those given in [1] for circuits containing only a few nonlinear elements (compared to the number of inductors and capacitors). The algorithm is based on a combined application of the harmonic balance and least square approach, and does not require any transient analysis.