Wave Equation-Based Discontinuous Galerkin Time Domain Method for Co-Simulation of Electromagnetics-Circuit Systems

In this article, a hybrid electromagnetic (EM)-circuit solver incorporated with wave equation-based discontinuous Galerkin time domain (DGTD-WE) method is developed to simulate microwave antennas and devices comprised of lumped circuit networks including arbitrary ports and both linear and nonlinear components. The computational domain is divided into two subsystems: one is the distributive part of the model which is modeled by the DGTD-WE method and the other is the lumped circuit networks which are analyzed by a SPICE-like transient circuit solver. In addition, a general impedance transmission boundary condition (ITBC) is introduced for the DGTD-WE method to model the interactions between the EM fields and the circuit networks. With the help of the proposed ITBC, coupling matrices between the two subsystems are small and highly sparse, and thus can be efficiently solved. Moreover, an average evaluation technique for the port voltage has been proposed to obtain a stable solution in the EM-circuit co-simulation. Numerical examples are presented to demonstrate stability, accuracy, and applications which extend the capability of the current DGTD-WE method to model hybrid field-circuit problems. Finally, the proposed method is validated experimentally using a diode mixer.