Research And Design Of Miniaturization FMCW Radar Measurement System

As an important type of radar,the frequency modulated continuous wave(FMCW)radar system posesses the advantages of easy implementation,high resolution,low power consumption,free of blind zone and strong anti-interference capability,which is widely applied in civil uses such as automotive collision avoidance,liquid level measurement,target detection and so on.Meanwhile,with the development of microwave monolithic integrated circuit(MMIC),the radar components are developing towards miniaturization,low power consumption and high frequency.Therefore,combining the advantages of the FMCW radar system with the trendency of radar miniaturization,the fundmentals and implementations of the miniaturized FMCW radar measurement system are researched in this thesis.The system composition and the measurement fundamentals of the FMCW radar system is studied in this thesis.Based on the miniaturization and low power consumption,a miniaturized FMCW radar system is designed and implemented by using MMIC microwave devices.The specific contents of this thesis are as follows:Firstly,the research of system composition of FMCW radar system is given,and the measurement fundamentals of the FMCW radar system are described.The measurement fundamentals of the sawtooth wave and the triangular wave modulation are theoretically deduced,and the formula of the beat frequency after demodulation with respect to the target range and velocity is obtained under the condition of the above mentioned two kinds of modulation.Additionally,the key factors influencing the accuracy of FMCW radar are also analyzed,and the improvement measures are presented,which provide the theoretical basis for the following design of FMCW system radar system.Secondly,the RF front-end of K band FMCW radar is designed and implemented.The implemention of discrete modules such as the RF signal source,power amplifier,low noise amplifier,mixer,filter and controllable gain amplifier is given.Among them,the phase locked loop(PLL)is used to generate the triangular wave modulation signal,where the bandwidth is 24-24.12 GHz and the modulation period is 2ms.And the observation of the target with the distance of 5m to 1000 m is achieved by observing the beat frequency signal.Finally,based on the K band FMCW radar transceiver front-end,the miniaturized FMCW system radar system is designed and realized.By integrating the K-band transceiver antenna,RF front-end and digital processor into a single printed circuit board(PCB),the volume and power consumption of the FMCW system radar system is further reduced.The PCB size of the whole radar system is only 78×65mm,and the overall power consumption is restricted to 6W.At the same time,the target detection range is 1m to 200 m and the resolution is 0.61 m.