An investigation of directive radiation from ultra subwavelength-thick planar antennas with partially-reflecting surfaces

In this paper we study the behavior of PRS-based planar directive antennas in which the thickness of the partially open cavity is considerably smaller than the (one-half dielectric wavelength) values typical of the usual Fabry-Perot designs. The performance of the considered antennas are investigated in terms of power density radiated at broadside and directivity in the principal planes, pointing out the main limitations and tradeoffs associated with the reduced thickness and discussing suitable modifications of the basic design to improve its performance.