A modeling method for equivalent source adopting volume structure technique in FDTD

The equivalent source is a widely used approach for simulating hybrid electromagnetic (EM) field-circuit problems. In this approach, three techniques, e.g., the wire, surface, and volume structure, can be employed for embedding lumped circuits into finite difference time-domain cells. However, the volume structure technique introduced in previous studies may result in incorrect answers when addressing problems consisting of electronic devices loaded onto conductor strip gaps. To fix this problem, an extra processing method is proposed. Based on the condition of consistent potential on the same tangent plane in the loading direction, this approach assigns the EM field on the grids occupied by the lumped circuit to obtain the equivalent source information. A numerical example is presented, the structure of which consists of a Schottky diode mounted across a microstrip gap. The results validate the feasibility of the proposed method.