Spectral-element analysis of microwave Gunn oscillator in the time domain

In this study, the microwave Gunn oscillator is analyzed by a hybrid electromagnetic-circuit simulator, which is based on the spectral-element time domain (SETD) method. The Gunn diode within the oscillator is treated as a lumped element, while the passive distributed part of the oscillator is modeled using the SETD method. In order to incorporate the contribution of the Gunn diode into the SETD context, the SETD method is extended by introducing a lumped current term into the second-order vector wave equation. After space and time discretization, a block-diagonal global SETD system involving the Gunn diode is assembled. The inversion of this matrix can be easily implemented, thus the extended SETD method is a fully explicit solver. Numerical results demonstrate the ability and effectiveness of this extended SETD method for the fast analysis of microwave Gunn Oscillator.