Applying the trigonometric collocation method to nonlinear circuits

We give a calculation procedure based on the Trigonometric Collocation method (TCM) for finding the steady-state response of forced nonlinear circuits. The periodic problem is reduced to solving a system of approximating equations, which are formulated in the time domain in terms of the samples of the sought oscillation. This formulation is shown to be equivalent, to that resulting from the Harmonic Balance method (HBM), but it overcomes some drawbacks in applying this method. The approximating equations, indeed, are given in explicit form in terms of problem variables and, consequently, the Jacobian matrix is computed by very simple formulae, and has a well-defined structure, which is memory-inexpensive