Multi-Beam Graded Dielectric Lens Antenna from Multi-Material 3D Printing

Abstract

Modern communication systems will require antennas with adaptive functionality which are able to modify their performance based on the requirements of the channel. For example, mobile ad-hoc networks need directive antennas that are able to radiate in any direction across the 360° azimuth plane. Conformal antennas that can be simply operated to have multifunctional performance characteristics are therefore of interest. In this paper, we present a gradient-index lens antenna designed to radiate with a 45° beamwidth across 8 different sectors. When fed by a simple switched feeding network, the lens is able to provide 360° azimuth coverage in 45° segments. Further analysis of the radiation patterns shows how two distinct multibeam patterns can be produced from simple feed networks and simultaneous excitation of each feeding element. The proposed lens is fabricated by multi-material 3D printing. The final lens radiates with a gain of 8.5 dBi when a single sector is excited, and with a maximum gain of 5.9 dBi in multi-beam mode. Finally, it is shown how the lens can also radiate omnidirectionally when optimised phase and amplitude weightings are applied to each port.