Reduction of the effects of dielectric coating with the extended ground on a small slot leaky wave waveguide antenna

The effects of a Teflon dielectric coating with the extended ground on the radiation characteristics of a small uniform longitudinal slot leaky wave waveguide antenna is investigated. Unwanted ripples, which are generated due to the surface wave excitation inside the dielectric and diffraction from the dielectric edges, are observed in the E-plane pattern. It is shown that the amplitude of the surface wave can be reduced by using conductor posts around the slot before reaching the dielectric edge. These posts help us eliminating the ripples from the E-plane pattern. Simulated and measured results for the antenna are presented and discussed.