Wideband dual circularly polarized coplanar waveguide-fed slot antenna with an arrow-shaped strip

A novel dual circularly polarized slot antenna with wideband characteristics is designed in this article. The quarter-wavelength patch mode and half-wavelength slot mode are combined in this antenna, which is excited by double perpendicular coplanar waveguide (CPW)-fed ports. The good circular polarization and isolation are achieved by the L-shaped ground plane and two open slots, respectively. The protruded arrow-shaped strip introduces a new monopole mode, which broadens the impedance bandwidth (IBW) and axial ratio bandwidth (ARBW). In addition, it simultaneously improves isolation as well. The proposed prototype provides an impedance bandwidth (|S-11| < -10 dB) 1.12-3.8 GHz (108.9%) and the ARBW is about 1.6-4.36 GHz (92.6%). Dual-port isolation is better than 10 dB within ARBW. Compared with others, the dimension of this prototype is more compact with wider IBW, wider ARBW, wider isolation bandwidth and better gain performance.