A 3D-printing metasurface-augmented half-circle Maxwell fisheye lens for millimetre-wave analogue beamforming

This article presents a 2D metasurface-augmented half-circle Maxwell fisheye lens (HMFL) designed to move its focal axis to a targeted direction with a maximum elevation angle of 45^◦, suitable for switchers and power division networks in the millimetre wave (mmWave) band. This metasurface-augmented beamformer enables consistent analogue performance across a bandwidth of 22 - 32 GHz. The proposed beamformer features a reflective metasurface consisting of 2 × 40 Phoenix unit cells and is integrated with a 10- dielectric zone HMFL in the diameter segment opposite the antenna source. A horn antenna feed is used for excitation in normal and oblique incidences of ϕi = −15^◦ and ϕi = −30^◦. The designed lens prototype was fabricated with 3D-printing technology and printed metasurfaces for several particular cases of focal displacement. The measurements of the proposed HMFL beamformer are presented, demonstrating a close correlation between simulated and experimental results.