Dielectric and metallic jointly 3D-printed mmWave hyperbolic lens antenna

A dielectric-metallic jointly three-dimensional (3D) printed V-band (50-75 GHz) lens antenna with preliminary surface roughness modelling is proposed. It takes full advantage of both the dielectric and metallic 3D printing technologies which help effectively to control the cost of the lens antenna. The stereolithography apparatus is used to form the lens using Somos Imagine 8000 resin, while the selective laser melting is used to fabricate the feed horn using aluminium alloy. A λ₀/4 matching layer is adopted between the feed and lens for reduced reflection. The surface roughness of the lens and the feed horn are characterised under a surface profilometer. Owing to the material and process, the surface roughness of the 3D-printed device demonstrates distinctive properties. A preliminary conjecture is made on the surface roughness distribution of 3D-printed devices that are helpful to predict roughness-related performance degradation. The antenna is characterised by electromagnetically and materialwise. It has impedance bandwidth of |S11|<-20 dB from 50 to 70 GHz with the in-band gain >32 dBi and symmetric radiation patterns on both E and H planes, which agrees well with simulation.