Research On X Band Level Measurement FMCW Radar System Design

No matter in modern life or industrial production, we demand a high level method of measuring distance. In many automatic and intelligent control systems, it is indispensable to measure the distance. The traditional methods of measuring distance can't meet the requirements of various situations; the distance which is obtained automatically and real-time is just what we need now. the X-band FMCW radar has the advantage of measuring the distance precisely and quickly, which has widely been used in vehicle collision avoidance system?radar level meter and radar altimeter. They all provide much convenience for our life and industrial production.A system of X-band FMCW radar is designed in this paper. This system has the advantages of high accuracy, intelligence and rapid measuring. In this system, we chose the Xilinx's Virtex-5 series FPGA as the core of signal processing and the STM32F407 as the auxiliary controller. A transmitter combined with a liner sweeping source based on HMC703 is built. We build the whole system and tested it in lab environment and field environment,reaching a relatively high level.First, this paper makes simple analysis of the FMCW radar background and describes the domestic and foreign development of the FMCW radar. Then we put forward the necessity of designing the FMCW radar system. Second, the FMCW radar theory, the method of measurement, the function of every module is completed and the technical requirements are presented in detail. Third, the radar system scheme based on the FMCW radar theory is put forward and so is the design method of transmitter and receiver in microwave circuit. At last,the radiation and receive module of the radar system is tested; all the experimental data obtained are analyzed and summarized.The test shows that the X-band liner sweeping signal generator has a very high linearity.The intermediate frequency signal which is related to the distance is obtained from the mixing of the echo signal and the transmitting signal. It is easy to do the subsequent data processing.This text aims at the summary of what has been done and the technical support for the further research of the FMCW radar system.