Study of surface waves on planar high gain leaky wave antennas

Much work has been devoted to gain enhancement of printed leaky antennas with one or more superstrates. However, little attention is paid to the excitation of surface waves, which can take away appreciable amount of power, thus reducing the net antenna gain. We present rigorous analysis for two and three dielectric layer antenna configurations for which radiation power and surface wave power are derived. It is shown that, for certain antenna parameters, surface wave power can considerably reduce the antenna efficiency and, therefore, the antenna gain.