Wideband Localization of the Dominant Leaky Wave Poles in Dielectric Covered Antennas

This letter discusses the properties of printed antennas whose radiation patterns (their directivity or their shape) are enhanced by means of dielectric superlayers which support leaky waves. In particular the characterizing complex leaky wave poles of the spectral Green\´s function are approximated analytically, for the first time over large frequency bandwidths. The localization of the poles is a simple mathematical "trick," however, the results provide further physical insights into wave phenomena that before had to be investigated numerically