A Wide-Beamwidth Dual-circularly Polarized Microstrip Patch Antenna with Stable Radiation Pattern for K-band

A beamwidth broadening structure of microstrip patch antenna is presented, which can effectively broaden the antenna beamwidth. It is different from the general microstrip antenna beamwidth that decreases with the increase of frequency, and has a stable radiation pattern. The proposed microstrip antenna is surrounded by an un-grounded parasitic metal vias, and the beamwidth increases from 88° to more than 120° in its operating bandwidth form 19.3GHz to 20.9GHz. The beamwidth of the antenna is significantly improved, and is stable with the change of frequency, the realized gain fluctuation is small. That is, it has a stable radiation pattern, which has the advantage of being applied to the wide-angle scanning phased array.