Conformal Precise-Integration Time-Domain Method for Analyzing Electromagnetic Fields in Fine-Structured Device With Moving 3-D Part

Herein, a novel method, referred to as conformal precise-integration time-domain (CO-PITD) method, which combines the precise-integration time-domain (PITD) method and the conformal mesh technique, is proposed to numerically calculate the evolving electromagnetic (EM) fields in the fine-structured device with moving part in time domain, particularly for 3-D case. The EM parameters in the computation cells partially occupied by moving medium are evaluated with the aid of the conformal mesh technique. For the implementation of the PITD method, the discretized Maxwell equations in those cells are modified due to the temporal variation, caused by the movement, of the EM parameters. Furthermore, the challenge from time-variant coefficient matrix is overcome by constructing an effective piecewise time-constant substitute. Meanwhile, the stability condition and the dispersive relation of the proposed method are both theoretically derived. The validity of the CO-PITD method is verified in the context of several numerical experiments. In addition, the comparisons with the established methods show that the proposed method is of excellent efficiency since a much large time step size is permitted in it.