Numerical Method for Antenna Radiation Problem by FDTD Method with PML

Summary

In the numerical simulation of electromagnetic wave radiation from an antenna, the antenna is assumed to be a perfectly conducting obstacle. It was shown numerically that the antenna can be effectively modeled by a highly conducting region occupied by it. The Finite Difference Time Domain method combined with Perfectly Matched Layer gives a flexible numerical methodology for this problem. We apply the method to analyze several radiation problems with different types of antennas such as a birdcage and the Yagi types where the delta gap type power supply model is adopted. For treating an unbounded outer region numerically, we apply a newly developed technique to discretize the PML region with little artificial reflection. Theoretical justification of this procedure for a 1D case was presented in DD17, and effectiveness of this technique was also demonstrated numerically for 2D and 3D cases. We observe a good 3D numerical performance of the method and confirm its usefulness though theoretical justification remains as a future problem.