Radar-based sensor device for e.g. automatic sliding-door system, has air gap smaller than 0.2 millimeters that is formed between flat top antennas and cover element or between flat top antennas and upper surface of substrate

摘要

A sensor is provided on a substrate (11) on which a patch antenna (11') is formed by arranging at least three flat top antennas one above the other. At least one cover element covers the flat top antennas. An air gap smaller than 0.2 millimeters is formed between the cover element and the flat top antennas or the upper surface of the substrate.