15. Wide-Angle Beam Scanning Antenna at 79 GHz for Short-Range Automotive Radar Applications

An antenna array with beam scanning capability operating in millimeter wave region (79 GHz) for automotive radar applications is presented. The proposed antenna array consists of 17 planar log periodic dipole antennas (PLPDA) and a cylindrical dielectric Luneburg Lens. The Luneburg Lens is utilized to enhance the gain of PLPDA, i.e., from 7.7 dBi to 16 dBi. The proposed antenna array structure is optimized to cover a wide scan angle of 180° in azimuth plane (θ = 90°) with impedance bandwidth of 6 GHz (76.5–82.5 GHz). The realized gain of center feed is found to be 16 dBi whereas it decays to minimum value to 13 dBi for the edge feeds of the 17 element PLPDA array integrated with Luneburg Lens. The crossover between the neighboring feeds in array is maintained to be 3 dBi. A comparison between the simulation and measured results is shown, which are found to be in a good agreement.