A Stable Potential-Based Time-Domain Method for Wideband Electromagnetic Analysis

In previous research, the frequency-domain <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{A}-\phi$</tex> formulation has been validated using the finite element method for electromagnetic simulations of low-frequency and multi-scale problems, demonstrating excellent numerical accuracy, good matrix condition, and high computational efficiency. Time-domain simulations provide significant advantages for modeling wideband problems and are crucial for multiphysics applications. In this paper, the frequency-domain <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{A}-\phi$</tex> formulation is extended to the time domain. The central difference scheme is employed for temporal discretization to ensure both accuracy and stability. A numerical example is presented to demonstrate the capability of the proposed time-domain method in wideband electromagnetic analysis.