Exact radiation from dipole antennas on prolate and oblate spheroids coated with two confocal layers of different materials

Metallic prolate and oblate spheroids are coated with two confocal layers of penetrable materials. One layer is isorefractive and the other layer is anti-isorefractive to the space surrounding the structure, thus resulting in four possible configurations. The primary source is an electric or magnetic dipole located on the symmetry axis of the spheroids and axially oriented. Exact solutions to the radiation problem are obtained in the frequency domain, in terms of infinite series of spheroidal wave functions. Numerical results are displayed and discussed.