A global finite-element time-domain analysis of active nonlinear microwavecircuits

An extension of the finite-element time-domain (FETD) method for mixed elec tromagnetic and circuit simulation of complex active microwave circuits is proposed in this paper, The passive distributed part of the circuit is anal yzed using FETD and its interaction with lumped passive/active linear/nonli near components is modeled via an equivalent-current generator whose value and internal capacitive admittance are computed at each time step by the FE TD solver. Benchmark tests on a microwave amplifier and a injection-locked oscillator indicate that this extended FETD is not only superior in mesh fl exibility, but also gives more accurate results than the similar FDTD-based algorithm.