Circularly Polarized Wide-Angle Beam Scanning Circular Array Antenna

In this paper, a left-handed circularly polarized wide-beamwidth array element is proposed with an overlapped impedance and 3-dB axial ratio bandwidth from 1.9GHz to 2.2GHz. It consists of a circular microstrip patch with rectangular notched structure as the main radiator, a circular parasitic patch and a metal ring to broaden the impedance and 3-dB axial ratio bandwidth, and four metal posts to improve the beamwidth. A 12-element circular array is formed by using the aforementioned element, which can realize a wide beam scanning range from -72 degrees to +72 degrees in the elevation plane.