Convergence improvements of the harmonic balance method

Harmonic balance based circuit simulators, which allow an efficient evaluation of the steady state solution in the frequency domain, still present convergence failures in nonlinear circuit analysis. Such problems are investigated, giving emphasis both to the numerical aspects and to the theoretical bases of the method. A technique of electrical filtering has been successfully employed to improve convergence capabilities in the harmonic balance based circuit simulation and the experimental results are reported together with the details of the method