Compact coplanar waveguide-fed wideband circular polarised antenna for navigation and wireless applications

In this study, a new compact coplanar waveguide-fed wideband circularly polarised slot antenna is designed and fabricated. To achieve circular polarisation, the slot in the ground plane is truncated at one corner and excited by a modified L-shaped radiating element. To achieve wide axial ratio bandwidth (ARBW), one end of the L-shaped patch is connected with the ground via a slit. The ARBW is further improved by properly placing two additional narrow slots in the ground plane. The measured impedance bandwidth and ARBW at boresight are achieved 87.2% (from 2.2 to 5.6 GHz) and 81.05% (from 2.2 to 5.2 GHz), respectively. For the better understanding, the surface current distribution and parametric studies are presented. To characterise the antenna in the time domain, group delay and system fidelity factor (SFF) are measured. The measured group delay has less variation (of 0.5 ns) in the operating band and the measured SFF is found to be 0.89. The measured and simulated results are in good agreement.