Design And Implementation Of Fmcw Ranging Radar

Frequency modulated continuous wave (FMCW) Radar is applied to various fields，owing toits good characteristics. One of the most basic and important functions of FMCW Radar isranging. With the increasing demand for ranging precision, further researches on FMCW Radarranging have become more and more significant.Based on analyzing the theory of FMCW Radar ranging deeply, a low cost and miniature24GHz radar ranging system is designed out in this thesis. Firstly, the principle of frequencymodulated continuous wave (FMCW) Radar ranging is introduced in detail, and, beat frequencysignal is analyzed respectively in time and frequency domain. Subsequently, the parameters of theradar ranging system are established according to theoretic and practical needs. Further more,according to each index, a digital temperature-compensation and nonlinear correction VCOscheme is designed in transmitter part. The actual circuit test shows that the degree of nonlinearityis less than5%after using this scheme. This thesis focuses on improving frequency estimationaccuracy without changing the sweep bandwidth. The methods are as follows: Firstly, theapproximate range of beat frequency signal spectrum peak value of FMCW Radar is obtained byusing FFT. Then, further estimating the maximum value of the range and calculating the mainlobe’s peak point among beat frequency signal’s spectrum. Thus, the high accuracy frequencyestimation is realized and the ranging precision is improved. On the basis of theoretical analysis,each components of the system is further designed and made, and, the hardware of the rangingsystem is worked out. Finally, the measured data of this system is collected and analyzed and thefeasibility of the signal processing scheme design is verified. The ranging accuracy is5mm.