Exact Dipole Radiation From an Oblate Semi-Spheroidal Cavity Filled With DNG Metamaterial

An oblate semi-spheroidal cavity is flush-mounted under a metal plane and is coupled to the half-space above the plane via its circular interfocal aperture. The cavity is filled with a lossless metamaterial whose refractive index is negative and the opposite of the refractive index of the medium filling the half-space above the cavity, while the intrinsic impedances of the two media may be different. An exact solution is obtained in terms of infinite series of oblate spheroidal wave functions, when the primary field is an axially-oriented electric or magnetic dipole located on the symmetry axis of the structure. Numerical results are presented and discussed.