Design And Implementation Of Vehicle Millimeter Wave Radar System

With the development of industries such as unmanned driving and urban intelligent transportation,77 GHz millimeter wave radar has been widely used as an important sensor,and the related technology has become a hot topic for research by technology companies in various countries.Several companies have already provided millimeter wave radar sensor chip solutions,but the design optimization of millimeter wave radar hardware system needs further research.In this thesis,the design of the millimeter wave radar circuit and RF system based on the IWR1843 millimeter wave radar sensor chip produced by Texas Instruments(TI)is carried out for the application scenarios of automotive radar.The main work is as follows:1.A hardware system consisting of three PCBs,namely a radar board,main control board,and data capture adapter board,was proposed from the perspectives of cost and external control,and the characteristics of the scheme were explained.And then according to the circuit function module on each PCB,the design process of circuit system schematic and PCB diagram is described,finally the PCB processing and patching is completed.2.According to the RF performance of the radar chip and application scenarios,the antenna indexes under short range detection(>70m)and medium range detection(>160m)are determined.The 1×4 and 1×10 line array antennas with center frequency of 79 GHz are designed for two detection distances using two line array optimization methods,respectively,and combined with HFSS simulation software for optimizing,the structure parameters of microstrip array antennas are finally determined.The simulation results show that the maximum gain of 1×4 antenna reaches 13.16 d Bi and the maximum gain of 1×10 antenna reaches 16.04 d Bi,both of which meet the distance detection requirements.3.Test work was performed on the fabricated system,including three parts: power supply,communication,and overall performance.The power supply part tested the power supply voltage,ripple and maximum current;the communication part tested whether the communication between the radar and MCU and between the systems could communicate through the specified communication protocol and reach the preset transmission rate;the overall performance part tested the overall directional pattern,distance measurement accuracy,distance resolution and angle resolution of the system.The test results show that the system with integrated 1×4 antenna and 1×10 antenna has a-3d B beamwidth in the E-plane of 19° and 8° respectively,which is close to the simulated value.The distance resolution is about 5cm at 3.5GHz swept bandwidth,and the angular resolution is 15° when using 2 transmitting and 4 receiving antennas,which are both close to the theoretical calculation results.In conclusion,this thesis proposes a millimeter wave radar hardware system structure in automotive application scenarios,and designs and manufactures the hardware system.Finally,testing and verification work is conducted.This work of this thesis has certain application value and design reference value in the field of engineering.