Wideband Multibeam Shared-Aperture Geodesic Half-Maxwell Fish-Eye Lens Antenna Based on 3D Printed Technology for 5G Applications

This paper introduces a novel implementation strategy for a shared aperture antenna that integrates lens antennas with low-frequency band antennas. Leveraging the concept of geodesic lenses, where rays follow “the shortest optical path” on a geodesic surface, we substitute the optical path with a microwave transmission structure, such as a parallel plate waveguide, enabling operation in microwave bands. We design a shared aperture Half-Maxwell fisheye lens (HMFL) antenna, structured as a quarter sphere that also functions as a low-frequency antenna's reflective cavity. This antenna operates in two large frequency-ratio bands, 26-40 GHz and 2.4-3.5 GHz, with a shared radiator structure. To mitigate costs, a metal 3D printing process is adopted for fabrication. Following the design and manufacturing stages, the antenna was measured. Results reveal that in the Ka-band, the antenna generates five high-gain beams, covering ±36deg of the horizontal plane (Theta = 84deg), with peak gains reaching 14.8-20.8dBi. In the low-frequency band, the antenna achieves a -10dB impedance bandwidth of 2.4-3.5GHz and a peak gain of 7.8 dBi. With its wide bandwidth, dual-band, multi-beam capabilities, and cost-effectiveness, the proposed antenna shows promising potential for 5G communication applications.