Development of a finite-difference time domain algorithm for body of revolution structures including a perfectly matched layers absorbing boundary condition

Various types of antennas and transmission media for electromagnetic waves exhibit symmetry around an axis of rotation and hence called bodies of revolution. The periodic behavior of the fields in the azimuth may be extracted analytically and the fields everywhere may be found by solving Maxwell's equations in a single two dimension plane. The body of revolution (BOR) approach has been used in the past with different numerical techniques for solving electromagnetic problems. Although the use of BOR approach with the finite difference time domain (FDTD) technique has already been reported, this work presents an advanced integration of the FDTD-BOR with the perfectly matched layer (PML) absorbing boundary condition (ABC). This implementation significantly reduces the undesired reflection of outgoing waves due to the mesh truncation for a wide range of frequencies. Good agreement with published computed and measured data are obtained with the developed FDTD-BOR-PML technique for dielectric resonators and microstrip patch antennas. A near to far field transformation is developed to obtain far field parameters. A sub-grid with finer discretization is added to the FDTD-BOR implementation to be able to model on axis sources with grater detail. The resulting code is a powerful tool to analyze a large variety of electromagnetic problems.