High gain wideband compact microstrip antenna with quasi-planar surface mount horn

We report a new compact square microstrip antenna with a surface mounted quasi-planar horn. The horn is made of plastic sheet and painted with silver epoxy. The horn improves the gain of the patch by 3-4.5 dB without adversely affecting bandwidth which is 2.3-9%.. Also the horn improves the isolation between array elements by 10 dB. The total thickness of antenna, including the horn, is only 6.94 mm.