System Design And Application Of Mm Wave Sensor

The traditional millimeter-wave radar system consists of discrete devices.The system debugging process is complex and large.With the development of large-scale integrated circuit device technology,the integration and performance of millimeter-wave sensors have been significantly improved from the initial Ga As process to Ge Si process to the latest CMOS process.At present,there are many types of millimeter-wave radar sensors,but there are few complete millimeter-wave radar systems with specific functions.Therefore,the research and design of millimeter-wave radar systems using millimeter-wave sensors have great value in the engineering field.In this paper,the research status of the application of millimeter-wave radar sensor and millimeter-wave radar sensor system at home and abroad is analyzed.At the same time,the framework and basic principle of FMCW radar system are introduced.The detection principle of linear frequency-modulated continuous wave radar is deduced,including distance measurement and range resolution,speed measurement and speed resolution,angle measurement and angle fraction.Resolution.In addition,this paper introduces and validates the performance improvement methods of FMCW radar system,including the improvement of ranging accuracy and angle resolution.In this paper,a single-chip high-precision ranging radar system and a multi-chip cascade radar system are designed to improve the ranging accuracy and angle resolution of the radar.(1)Single-chip high-precision ranging radar system,according to the requirements of indicators,analysis and comparison of the system implementation schemes,select TI IWR1642mm-wave sensor to complete the system design.The system design first designs the 77 GHz microstrip array antenna according to the Taylor synthesis method,then designs the hardware circuit,including the RF front-end circuit design,power circuit,storage circuit and emulator circuit.At the same time,the design of hardware circuit schematic and PCB design and processing are completed.Finally,Zoom is used.The FFT algorithm completes the design of high precision ranging algorithm.In the system test,the pattern of 77 GHz antenna is tested first.The E-plane half-power beam width of the antenna is 5.7 degrees,and the side-lobe level is-25.1d B.The results are in agreement with the simulation results.After the system function test,the final ranging error maximum value is 4 mm,the average value is 1.93 mm,indicating that the system can reach the ranging accuracy of 5 mm within 6 m of the measurement distance,which meets the system design requirements.(2)Multi-chip cascade radar system,based on the principle of MIMO,a four-chip cascade application scheme is proposed.First,the difficulties in cascade system are analyzed.The layout of multiple transmit and receive antennas is applied with MIMO principle.The antenna array can improve the system azimuth and pitch resolution,and the synchronization signal of cascade system is analyzed.Then the system passive and active circuits are designed according to the system requirements.Passive circuit consists of 40 GHz power divider and GCPW to SIW structure.The influence of through hole on signal transmission is analyzed in 40 GHz power divider design,and a multi-layer PCB through hole model is established to optimize it.The active circuit uses ADAR6902 as RF transceiver chip to complete the cascade system schematic and PCB design.