Exact radiation by isorefractive slotted elliptic cylindrical antenna

Exact solution of the electromagnetic radiation from a conducting slotted elliptical cylinder coated by an isorefractive material derived using the separation of variables technique. The fields inside and outside the dielectric layer are expressed in terms of Mathieu functions. No matrix inversion is required after obtaining exact expressions for the radiated field expansion coefficients by imposing the appropriate boundary conditions. Numerical results are plotted for the radiation pattern, aperture conductance and antenna gain. The results show that a slotted antenna coated with isorefractive material has more directive beam and lower side-lobes compared to that coated with conventional dielectric material of comparable physical dimensions.