A K-Band 3-D Printed Focal-Shifted Two-Dimensional Beam-Scanning Lens Antenna With Nonuniform Feed

摘要

A K-band (18-26.5GHz) two-dimensional (2-D) beam scanning antenna is proposed. The hyperbolic lens is fed by an array of focal-shifted horns with nonuniform aperture. The feed at the focal point of the lens generates the boresight vertical beam, while the off-focal feeds are responsible for tilted beams. The nonuniform horn aperture helps to mitigate the gain decrement from the lens aperture tapering. It is fabricated taking full advantage of dielectric and metallic 3-D printing technologies. The lens is printed by stereolithography apparatus (SLA) in resin. The feed horn array is printed by selective laser melting (SLM). Process-wise, it features low cost, short turnaround time, and the capability to implement complex geometries versus traditional computer numerical control machining and mold casting. Simulation and measurement indicate that the antenna features desirable matching below -15dB and mutual coupling between adjacent port below -25dB. The gain is above 23dBi across the K-band. Multiple beams at 32, 12, and 0 are observed on E- and H-planes. The proposed design can either function as multibeam antenna or a beam-scanning antenna together with switches. It is a capable candidate for applications such as multiple target tracking and wide region monitoring.