A Low-profile Dual Circularly Polarized Strip Line Feed Antenna with wide Axial Ratio Bandwidth

This paper proposes a simple low-profile dual circularly polarized (CP) strip line-based feed monopole antenna with wide axial ratio (AR) bandwidth. A microstrip line is printed on the top side of an FR-4 substrate, and a wide-slotted ground with a metallic strip is printed on the other side of that substrate. The orthogonal placement of microstrip feed line and the metallic strip of the ground plane helps to generate dual CP radiation. This simple structure of the proposed CP antenna offers an impedance bandwidth (IBW) of 19.40% (4.84GHz to 5.88 GHz), and ARBW of 39.02% (4.62GHz to 6.86 GHz), covering the wide range of sub-6 GHz band. Furthermore, it exhibits dual CP radiations (both LHCP and RHCP) across the operating band, which is the key feature of the proposed antenna. This simple structure of dual CP antenna can be widely used in navigational applications.