A Ka-band high-efficiency dielectric lens antenna with a silicon micromachined microstrip patch radiator

Novel antenna configurations suitable for millimeter-wave applications were proposed incorporating a dielectric lens antenna with a single microstrip patch radiator. In general high aperture efficiencies are easily obtainable with lens antennas because of flexibility in controlling the aperture-field distribution coupled with low feeder loss. The radiator was integrated with front-end circuits into a single hybrid IC using silicon micromachining and BCB (benzo-cyclobutene) multi-stacked circuit processes. The radiator was constructed on a thin suspended BCB film to suppress dielectric and conductor loss. A demonstration radiator showed good performance at 39 GHz (Ka-band). The lens was designed using geometrical optics relative to the directivity of the radiator and the aperture-field distribution. The circular polarized lens antenna assembly exhibited a gain of 15.7 dBi, 18.7 dB side-lobe level suppression and 0.17 dB axial ratio.