Rapid-based Electromagnetic Analysis Mode Superposition Domain Spectral Element

Numerical methods in Time Domain have been widely used in the fields of Electronic Engineering.The simulation and analysis in time domain is particularly important in areas involving the research on the broadband characteristics and transient response, such as the RF circuits design, electromagnetic compatibility (EMC), communication channel, the radar’s target detection and recognition etc.In this paper, the classical Modal Superposition Method (MSM) in structural dynamics combined with Spectral-Element Time-Domain method(SETD) has been employed to solve EM Wave Equation. By Introduction of the absorbing boundary condition, the method is used to deal with the resonant cavity, waveguide and microstrip circuit problems. The treatements of the method with the first-order absorbing boundary condition and perfect match layer have been introduced. The loss case has also been taken into consideration and eigenvalue theory analysis has been done. Those works fully display the applicability of this method and its aracteristics of timesaving and accurate. In addition, the numerical stability could also be improved by this method.Based on the classical Modal Superposition Method and SETD method, this paper presents an Improved Modal Superposition Method (IMSM) which can effectively reduce the computational complexity of the large scale eigen-problem. This method will utilize the SETD method’s results to reduce the size of the original linear system of equations. The solving of reduced system will be much faster than the original one. In comparison with the classical MSM, the superiority of the improved method has been demonstrated.In addition to the application on the infield EM problem, the IMSM-SETD is also used to solve the backward scattering problems. At last, two classical numerical examples have demonstrated the validity of the proposed method in solving the transient scattering problems.