Abstract
ABSTRACT This work presents a millimetre‐wave antenna–metalens system based on the Pancharatnam–Berry phase principle. The setup includes a circularly polarised horn antenna combined with bi‐layer metalens optimised for 87 GHz operation. This arrangement achieves an axial ratio (AR) of 0.5 dB, directivity up to 34.7 dB–surpassing the original horn antenna over 17 dB–an aperture efficiency of 47% and exhibits a narrow beamwidth. The system operates from 82 to 95 GHz with an AR below 2 dB, directivity over 32 dB and aperture efficiency exceeding 30%. Additionally, the same metalens is characterised at 75 and 105 GHz, where the focal shift associated with frequency scaling is observed, yet directivity remains around 32 dB and AR below 3 dB. Notably, the aperture efficiency remains approximately 30% for the full frequency range, demonstrating the inherent frequency tolerance of the Pancharatnam–Berry phase implementation.