一种时域电磁仿真终止判断的新方法

摘要

Because of the slow decay of energy,program has to be run for a large number of simulation steps before getting the response of resonant structures in the application of time domain electromagnetic solvers.To solve this problem,the Vector Fitting technology was employed to predict the frequency behavior based on a reasonable number of initial time steps.Then the predicted results were compared with the results from the previous iteration steps by the Feature Selective Validation method.Output of Feature Selective Validation method was adopted as the stopping criterion of the simulation.Also,relationship between the length of comparing step and stopping criterion was discussed.Calculation of the shielding effectiveness of a metal box with aperture was adopted to validate the proposed stopping criterion that is compared with traditional criterion based on energy attenuation.It is demonstrated that proposed stopping criterion can save simulation time that is consumed to reach the predefined accuracy.Therefore,it is useful to apply the vector fitting and feature selective validation method to the stopping criterion of time domain electromagnetic solvers for the simulation of resonant structures.%时域电磁仿真方法在求解谐振结构响应时能量耗散慢,为了获取理想的频域结果,需要大量的仿真步数.采用矢量拟合方法对频域仿真结果根据已有初始频点进行预测,同时采用特征选择验证方法对相邻两次拟合结果进行相似度比对,使用特征选择验证方法的输出结果作为仿真终止的判据,并讨论了对比步长与收敛判据之间的关系.使用开缝金属箱体的屏蔽效能仿真算例验证判据的有效性,并与传统基于能量衰减的仿真终止判据进行性能对比.实验表明,提出的方法在保证仿真精度的同时可以节省谐振结构的仿真时间,说明使用矢量拟合和特征选择验证方法进行谐振结构的时域仿真收敛判断是有效可行的.