FDTD2 Simulation of Plane Wave Incident on Perfect Electric Conductor Plate

In electromagnetic field simulations, the Finite-Difference Time-Domain (FDTD) method is a widely used numerical computation technique particularly suitable for modeling interactions between electromagnetic waves and various material structures. When simulating plane wave incidence on a perfect electric conductor plate, FDTD clearly demonstrates the electromagnetic wave reflection process through iterative field updates using Maxwell's curl equations discretized in both space and time. The treatment of perfect conductor boundary conditions is crucial for this type of simulation. In the FDTD algorithm, perfect conductor boundaries imply zero tangential electric field components, which can be implemented by setting appropriate field update rules at the conductor surface using Dirichlet boundary conditions (E_tangential = 0). When the incident wave reaches the conductor surface, complete reflection occurs, generating a reflected wave with the same magnitude but opposite phase, achieved through careful implementation of boundary value assignments in the Yee grid structure. PML (Perfectly Matched Layer) serves as an absorbing boundary condition that effectively absorbs outward propagating waves, preventing unphysical reflections from interfering with simulation results. When configuring PML parameters, attention must be paid to thickness and absorption coefficient selection to ensure optimal absorption performance within limited computational resources. This typically involves implementing graded conductivity profiles using sigma_max and polynomial grading functions in the code. By analyzing simulation results, one can clearly observe the entire process of electromagnetic wave reflection at the conductor surface: including the superposition of incident and reflected waves forming standing waves, changes in wavefront propagation direction, and other physical phenomena. This simulation is highly beneficial for understanding fundamental principles of electromagnetic wave interactions with conductors, with implementation requiring proper source excitation (e.g., sinusoidal or Gaussian pulses) and field monitoring through time-stepping loops and spatial sampling points.