Horn and Prism Antenna for Dual Range and Dual FOV Automotive Radar Using 77-GHz Band

A novel antenna with a horn array was investigated for a dual range and dual field of view (FOV) automotive radar that uses the 77-GHz band. The structure of the antenna, composed of three types of horn, lens, and prism antennas with different directivities, produces a radiation pattern that had both a narrow FOV at a long-range detection and wide FOV at shortrange detection. A fabricated antenna achieved an antenna gain of 21.5 dBi and a 3-dB beam-width of 22 degrees at boresight and an antenna gain of more than 15 dBi within an angle of ±35 degrees in azimuth. The antenna had a matching band-width of 7 GHz, where the reflection co-efficient, S11, was below -10 dB.