Research On 77GHz Millimeter-wave Automotive Radar Antenna And RF Circuit

With the increasing demand for driving safety and the development of autonomous driving technology,millimeter-wave radar in automotive systems,including antennas and RF circuits,have received widespread attention and research from scholars both domestically and internationally,due to their advantages of all-weather operation and high resolution.This paper focuses on in-depth research on 77 GHz millimeter-wave radar antennas and RF circuits,with the following specific work:Design of antenna array for short-range detection in automotive radar.Short-range radar is commonly used for functions such as blind spot detection and pedestrian detection,and requires antennas with wide azimuth beamwidth,flat gain,and narrow elevation beamwidth with low sidelobes.In this paper,a 10-element patch-fed microstrip antenna is designed using the Dolph-Chebyshev array synthesis method,by adjusting the patch width of the antenna elements to control the current ratio,achieving the requirements of narrow elevation beamwidth and low sidelobes.The center frequency of the antenna is 76.8 GHz,with an impedance bandwidth of 0.9 GHz(76.4 GHz to 77.3 GHz),and a maximum gain of 14.6d Bi.Subsequently,to further widen the azimuth beamwidth,a wide-beam array antenna with14 elements based on a multilayer structure is designed using the features of substrate integrated waveguide(SIW)with low profile,low loss,and low scattering.The design requirements of wide beamwidth are achieved by changing the radiation characteristics using the dielectric and radiation patches on the upper layer covering the gap.The measured impedance bandwidth is 2.6 GHz,and the gain is 11.6 d Bi.The half-power beamwidth in the E-plane is 139.2°.Design of beamforming antenna array for medium to long-range detection in automotive radar.To improve the traditional approach of using discrete transmit antennas for medium to long-range detection,an integrated antenna array is designed based on beamforming theory in this paper.Firstly,the optimal configuration of the array is obtained using a genetic algorithm for the ideal state,and then the feeding network is designed based on the required power and phase distribution of the array.Simulation results show that the antenna array has a " flat-shoulder-shaped" radiation pattern,which can simultaneously meet the requirements of medium to long-range radar detection.Hardware design of 77 GHz millimeter-wave radar transceiver system for automotive demand.Based on the MIMO principle,the designed patch-fed microstrip antenna is used as the transceiver antenna element,and a layout of multiple transceiver antennas is completed.Device selection,circuit design for voltage division,storage,and high-speed interfaces are carried out according to the requirements of the AWR1843 integrated transceiver chip,and the schematic and layout design of the millimeter-wave radar transceiver circuit are completed.Finally,processing and testing are carried out,and the transceiver module can be used to measure the azimuth of single or multiple targets,with complete functionality overall.