Implicit incorporation of nonlinear elements for unconditionally stable FDTD analysis at coarse time-steps

摘要

A hybrid 3D FDTD algorithm with a fully implicit interface to lumped nonlinear multiport devices is presented. The algorithm is unconditionally stable and converges for arbitrarily strong nonlinearities, high voltages and with any time-step satisfying the Courant condition. In case of a strongly nonlinear bipolar transistor, the new algorithm is by over two orders of magnitude faster than previous FDTD schemes with explicit or semi-implicit interfaces.