Low-Profile 77-GHz Lens Antenna With Array Feeder

A 77-GHz lens antenna for automotive radar applications is presented. It consists of a feeder in the form of a 2×2 patch array etched from a single layer on a 100-μm-thick substrate and a commercially available dielectric lens. Compared to previously published lens antennas, the presented design has the advantages of excellent electrical performance and a low profile in combination with a thin lens. Measurements of port impedance match and radiation patterns are presented. Beam tilt by lateral offset of the lens is demonstrated experimentally.