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

This letter 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 fish-eye lens 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 to 40) GHz and (2.4 to 3.5) GHz, with a shared radiator structure. To mitigate costs, a metal 3-D 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 ±36° of the horizontal plane (Theta = 84°), with peak gains reaching (14.8 to 20.8) dBi. In the low-frequency band, the antenna achieves a −10 dB impedance bandwidth of (2.4 to 3.5) GHz and a peak gain of 7.8 dBi. With its wide bandwidth, dual-band, multibeam capabilities, and cost-effectiveness, the proposed antenna shows promising potential for 5G communication applications.