Modeling of a slot-excited spherical-circular microstrip antenna

Conformal printed antennas are frequently used in mobile wireless communications and radar due to their low profile and light weight. In this paper, the problem of modeling of a spherical-disk conformal printed antenna is considered assuming excitation by a slot. The slot is modeled by a tangential magnetic dipole located at the surface of the metal sphere covered with dielectric. Previously, similar problems have been analyzed by the method-of-moments. However, the accuracy of these numerical approximations suffer if narrow resonances are present. We propose an exact mathematical method based on the analytical inversion of the free-space static problem for a spherical disk. This method is very stable and gives fast numerical solutions.