A Study of Electromagnetic Radiation From Monopole Antennas on Spherical-Lossy Earth Using the Finite-Difference Time-Domain Method

Radiation from monopole antennas on spherical-lossy earth is analyzed by the finitedifferencetime-domain (fdtd) method in spherical coordinates. a novel generalized perfectlymatched layer (pml) has been developed for the truncation of the lossy soil. for having an accuratemodeling with less memory requirements, an efficient non-uniform mesh generation scheme isused. also in each time step, computation is limited to that part of the mesh where the radiated pulseis passing (computational window), in this manner, the values of radiated field at far distances can beobtained directly by the fdtd method. the spatial distribution of radiated field and the influence ofthe ground screen on monopole's admittance are shown in illustrations.