MATLAB Source Code Implementation of FDTD (Finite-Difference Time-Domain) Algorithm

This article presents MATLAB source code implementing the FDTD (Finite-Difference Time-Domain) algorithm, a powerful numerical method for solving time-varying electromagnetic field problems. The implementation utilizes MATLAB's computational capabilities to discretize Maxwell's equations using central-difference approximations in both space and time domains. The code structure includes key components such as field initialization, Yee grid implementation, absorbing boundary conditions (ABC), and time-stepping loops with stability-controlled Courant conditions. Our MATLAB-based implementation allows straightforward modification and adaptation to specific application scenarios through configurable parameters for grid resolution, source excitations, and material properties. Beyond providing complete source code, we include comprehensive documentation detailing the algorithm's mathematical foundations, implementation approaches for handling dielectric materials and boundary conditions, and practical usage examples. Each major function is commented to explain its role in the FDTD workflow, including electric and magnetic field updates, source injection routines, and field monitoring points. This resource serves as a valuable tool for engineers and researchers working on time-domain electromagnetic simulations, offering both educational insights into FDTD methodology and a practical foundation for developing customized electromagnetic solvers. The code demonstrates proper implementation of numerical dispersion control and stability criteria essential for accurate simulation results.