FDTD electromagnetic simulation-Finite Difference Time Domain

FDTD(Finite Difference Time Domain) is one of the electromagnetic simulation technique. The computational electromagnetism helps to find solutions to maxwell equations at the boundary conditions. It involves very efficient and complex alorithms running in the back end to produce the desired goal. Computational electromagnetism is also referred as CEM. Implementation of CEM is carried out after considering several factors viz. accuracy, scalability, stability, parallelisation, flexibility etc.

There are three techniques under computational electomagnetics. They are static method, numerical method and high frequency method. Integral and differential fall under numerical type of method. Field based and current based fall under high frequency based electromagnetic simulation.

There are time based and frequency based differential simulation techniques. As FDTD is a time based technique, single simulation can result into results for wide frequency range. Frequency domain results can also be obtained with the help of converting time domain results into frequency domain by DFT technique. The demerit of FDTD simulation is that simulation for each port need to be carried out separately consuming more time.

The applications of FDTD electromagnetic simulation are as follows:
•  Antenna placement on trains and cars
•  Time domain reflectometry
•  Large electric devices having lesser number of ports

Software Tools for computational electromagnetics

CST MWS (Computer Simulation Technology Microwave Studio) is one such tool providing six solvers for RF and Microwave designers. It includes time domain solver, frequency domain solver, Eigen mode solver, Integral solver, Asymptotic solver and multi-layer solver.

Other than CST MWS, HFSS and FEKO are popular softwares for this application.


FEM simulation
wireless system overview
Antenna tutorial
Maxwell electromagnetic equations

RF and Wireless Terminologies