Characterizing Low-Frequency Scattering by Discontinuous Galerkin Integral Equation Method in the Time Domain

This letter presents a novel method for solving ultra-low frequency electromagnetic scattering using the discontinuous Galerkin electric field integral equation (DGEFIE) in the time domain. The nonconformal nature of DGEFIE makes it challenging to apply methods such as loop-tree, loop-star decomposition to solve low-frequency problems. Therefore, we propose a method for the computation of scattering results of extremely low frequency under nonconformal mesh conditions, covering both near and far electromagnetic fields. Specifically, the proposed method can handle electrical sizes ranging down to 10⁻⁴³λ, overcoming the numerical breakdown issues at low frequencies. Moreover, this method can be easily integrated into existing codes. Several typical examples demonstrate the accuracy and effectiveness of the proposed method.