Simple FDTD Algorithm Implementation

In this article, we demonstrate how to implement a simple Finite-Difference Time-Domain (FDTD) algorithm using MATLAB, which can simulate both point sources and Gaussian-distributed planar wave sources. The implementation encompasses the core FDTD methodology involving staggered grid arrangements for electric and magnetic fields (typically using Yee's algorithm), temporal updating schemes based on Maxwell's curl equations, and proper boundary condition handling. We will discuss fundamental FDTD concepts including the leapfrog time-stepping approach, spatial discretization using central differences, and stability criteria governed by the Courant-Friedrichs-Lewy (CFL) condition. The MATLAB code implementation features key components such as field initialization matrices, source injection mechanisms (both hard and soft sources), and Gaussian pulse generation with adjustable bandwidth parameters. Through detailed code examples and explanatory comments, readers will gain practical understanding of FDTD implementation techniques, enabling them to enhance their computational electromagnetics skills and apply these methods to more complex simulation scenarios.