A low sidelobe 77 GHz centre‐fed microstrip patch array antenna

Abstract

AbstractA low sidelobe 77 GHz centre‐fed microstrip patch array antenna is proposed for automotive radar application. The proposed antenna comprises eight linear antenna arrays, each of which is centre‐fed by a coplanar waveguide with ground transmission line at the back of the microstrip patches. Each linear antenna array contains 10 patch antenna units, which are connected through a T‐type power divider network to achieve a −30 dB Taylor weighted distribution. The simulation results show that the designed phased array antenna has a good one‐dimensional phased scanning ability of ±45° with active voltage standing wave ratio less than 2 at 75–79 GHz, along with −20 dB low sidelobe symmetrical radiation patterns in the H plane. An antenna sample fed by a WR12 waveguide is fabricated and measured to verify its performance. The measured VSWR is less than 2 at 73.6–85 GHz. This design provides a new idea for millimetre wave automotive radar antenna design.