Implementation of Absorbing Boundary Conditions Using PML in 2D TM Wave FDTD Simulation

This program implements a 2D Transverse Magnetic (TM) wave simulation using the Finite-Difference Time-Domain (FDTD) method with Perfectly Matched Layer (PML) absorbing boundary conditions. The implementation, named FDTD_2D_kongqi_PML, specifically models Ez (z-component electric field), Hx (x-component magnetic field), and Hy (y-component magnetic field) components. The PML implementation employs conductivity grading and complex coordinate stretching to minimize reflections at computational boundaries, ensuring accurate wave propagation simulations. The code structure typically involves separate update equations for electric and magnetic fields within the PML regions using split-field formulations. Key algorithmic features include: Yee grid discretization for spatial sampling, leapfrog time-stepping for temporal evolution, and PML parameter optimization for broadband absorption. The implementation handles field updates through central difference approximations of Maxwell's equations while maintaining numerical stability via Courant condition adherence. This simulation tool provides researchers and engineers with reliable 2D TM wave analysis capabilities for applications in electromagnetic compatibility, antenna design, and photonics. The PML-boundary approach significantly reduces simulation domain size requirements while maintaining numerical accuracy through effective wave absorption at boundaries.