Circular Polarized 3-D-Printed Dielectric Loaded Antenna Using Inset Waveguide-to-Dielectric Transition for 5G Millimeter-Wave Application

This letter presents a millimeter-wave circular polarized dielectric loaded antenna (DLA) using an inset waveguideto-dielectric transition. Driven from demands over the perspective of low cost and high integration, the proposed design provides a cost-effective small volume and light-weight solution for millimeterwave (mm-wave) communications. A low-profile low-loss highintegration transition (0.17λ) is realized between air-filled waveguide and dielectric-filled waveguide. The proposed DLA could be excited with high-order modes to achieve narrower beamwidth and lower cross polarization. The seamless integration of DLA with the transition has been implemented by the use of 3-D printing fabrication technique. It has a light weight of 4.17 g, which is less than the weight of a standard A4 size paper. The simulated results show that the designed DLA can achieve a 28.6% impedanceand axial-ratio bandwidth and a peak gain of 12.0 dBic. The factors with strong influences on the measured results are analyzed. Comparing with the air-filled metallic waveguide antenna with similar performance, the proposed 3-D-printed DLA shows a 43% reduction in volume and a 90% reduction in weight, which is suitable for 5G/6G enabling antenna systems.