Millimetre‐wave high‐gain circularly polarised SIW end‐fire bow‐tie antenna by utilising semi‐planar helix unit cell

In this work, a high‐gain circularly polarised (CP) substrate integrated waveguide (SIW) bow‐tie antenna is presented. The proposed antenna includes a pair of bow‐tie radiators. To centralisation radiated pattern and recede side lobe and back lobe level two tilted rows of metalised via hole at the end of the SIW feed line is used. The methods of increasing the antenna gain and generating the CP are discussed. The proposed antenna was fabricated to validate simulated results. The designed structure operates across 40–68 GHz and exhibits a gain of 10–12.5 dBic. In addition, the proposed antenna exhibits a 3‐dB axial ratio bandwidth from 54 to 64.3 GHz.