Pair of diagonal slots loaded low‐profile circularly polarised patch antenna with wide 3 dB axial ratio beamwidth

A low‐profile circularly polarised (CP) antenna with wide 3 dB axial ratio beamwidth (ARBW) is proposed in this study. The possibilities of widening the 3 dB ARBW of single diagonal slot‐loaded conventional CP antenna have been explored successfully by incorporating a pair of rectangular slots along the diagonal line of a square patch antenna. The design parameters and the symmetrical arrangement of this pair of slots across the centre of the patch are crucial to adjust and achieve the wide 3 dB ARBW with high CP purity. Coupling between the two diagonal slots provides nearly equal and radiation patterns over a large angular range, and hence the 3 dB ARBW has been enhanced by 85.71 and 55.4% for = 0° and = 90° planes, respectively, in comparison to the conventional slot‐loaded CP antenna. The minimum 3 dB ARBW of 208° and a maximum of 230° have been achieved across different planes of radiation = 0°, 45°, 90°, and 135° with a minimum axial ratio of 0.20 dB only. The absolute planar antenna of size (0.29 × 0.29 × 0.013)λ 0 3 , where λ 0 is the free‐space wavelength corresponding to the CP frequency, has been fabricated and tested. The measured and simulated results show fair consistency to each other.