Fast Numerical Method for Computing Resonant Characteristics of Electromagnetic Devices Based on Finite-Element Method

The traditional method to obtain the response of electromagnetic devices over a wide frequency range is to use a frequency sweeping method. However, this method is very time consuming, especially in the time-domain analysis. In order to save the heavy computational time, a novel fast algorithm based on the finite-element method (FEM) to obtain the response under different frequencies is therefore proposed. With this proposed method, the FEM just needs to be solved once under a specific excitation function, and the frequency-domain responses at different frequencies are calculated using a simple integral formula. In this paper, a simple RLC circuit and a planar spiral coil are used to showcase this method. The results indicate that this method can obtain the resonant frequency of the system precisely with significant savings in computation time.