Bandwidth Enhancement of a Comb-Line Array Antenna for mm-Wave Automotive Radar Applications

Bandwidth enhancement of a comb-line array antenna for millimeter (mm)-wave automotive radar applications is proposed. The proposed antenna consists of 12 radiating elements, 13 parasitic elements and 12 slots, which staggered up and down on the feeding line. By adjusting the width and the length of each radiating element, the antenna achieves a low sidelobe. Meanwhile, a wide impedance bandwidth is obtained by adding parasitic elements. The proposed antenna is fabricated and measured. The simulation and measurement are in good agreement. Experimental results show that the antenna has a 10-dB impedance bandwidth over 75.1-80.3 GHz with a low sidelobe level of -18.9 dB.