Optically Transparent Antenna Integrated inside a Headlamp for Automotive Radar Application

A concept for integrating antenna inside a headlamp for automotive radar application is presented. The antenna comprises the primary (feed), which is embedded within the electronic unit, and the secondary one, which is made of transparent materials. The primary antenna can be the conventional one (e.g., patch, slot, sectoral horn), which is optically non-transparent. It is hidden from the optical path of the headlight. The secondary antenna is realized as a planar offset reflector, which is designed to collimate or shape the wave from the primary antenna. It is inserted in the space between the headlamp cover and the light unit. An antenna demonstrator has been fabricated, and together with the headlamp cover, the radiation pattern and realized gain are measured. We reported here the measurement results for several configurations and concluded that the headlamp cover gives minimal influence on the antenna performance.