EFFECT OF DIELECTRIC LOADING ON THE RADIATION POWER OF AN AXIAL SLOT ANTENNA.

Input admittances of an axial antenna on a perfectly conducting circular cylinder coated with a dielectric material are found for different permittivity and thickness of the dielectric as well as the radius of the conducting cylinder. The coating thickness for a given dielectric constant is chosen such that no axial surface waves are excited and consequently variation of the input admittance gives directly the variations of the radiation power. It is found that in this range of the dielectric thickness and for a given dielectric constant, the radiated power increases gradually with the thickness. Similarly, for a given thickness of the dielectric layer, the radiated power increases with increasing dielectric constant.