Design of a dual‐CP gap waveguide fed aperture array antenna

Abstract

AbstractA slot array antenna with dual‐circular polarisation (CP) is presented in this paper. To overcome the fabrication and loss challenges in mm‐wave frequencies, the gap waveguide technique is utilised. The right and left hand circular polarisation (RHCP and LHCP) radiations are achieved using slots‐fed stepped septum polariser on the longitudinal slot arrays. The waveguides and feeding layer are based on ridge gap waveguide. The experimental results demonstrate the |S11| and axial ratio of proposed antenna array are lower than −10 and 2 dB, respectively over the frequency range of 29.1–31.7 GHz. The proposed antenna exhibits the measured peak gain of 27.2 dBic at 30.2 GHz. The results prove that the proposed array antenna is a brilliant choice for 30 GHz‐band applications and could be developed to realise larger dual‐polarised planar arrays.