Enhanced Gain Patch Antennas at Millimeter Waves

A study of a rectangular patch, with a dielectric plate installed in front of the patch at a "resonant" distance, has been performed at the upper Ka frequency band. For this purpose three antennas have been designed, analyzed, built and measured. These antennas are: a "conventional" rectangular patch; an enhanced gain rectangular patch (a "conventional" patch with a dielectric plate in front of it); and an "equivalent" 2×2 array of "conventional" patches with the beamwidth nearly the same as that of the enhanced gain patch antenna. A significant increase in the gain of the enhanced gain patch antenna as compared with the "conventiona" one, was initially predicted theoretically based on the analysis, and then, confirmed by the measurements. In addition, it was shown that the enhanced gain patch antenna exhibits a larger gain and essentially lower sidelobes than the "equivalent" array.