Nonlinear circuit analysis through periodic spline approximation
F. Filicori, M. R. Scalas, Carlo U. Naldi · Electronics Letters · 1979
A spline representation is proposed for the current or voltage periodic waveforms at the connections between the linear and nonlinear subnetworks into which the circuit is partitioned. The periodic steady-state analysis is thus reduced to the solution of a nonlinear system whose unknowns are the knot ordinates of these splines.