Layer-to-layer ceramic stereolithography for the design of extended hemispherical lenses at 60 GHz

A layer-by-layer stereolithographic process has been developed successfully for the fabrication of integrated lens antennas made in alumina in V-band. The role of the matching layers and corrugated surfaces to reduce the influence of multiple internal reflections has been highlighted. In particular we have designed and characterized a broadband synthesized elliptical lens antenna fed by a dielectric-loaded rectangular waveguide: its -10 dB return loss bandwidth and -1 dB directivity bandwidth equal 20 GHz and 17 GHz around 60 GHz, respectively. The experimental results are in good agreement with the FDTD predictions despite the bending effects observed on the fabricated prototype after sintering.