Design Of The 24GHz FMCW Radar Transceiver Front-end

With the progress of The Times and the innovation of technology,MMW has been widely used,and MMW radar technology is frequently used in the fields of modern automobile and aviation,ranging radar is one of the typical applications.In this paper,a transceiver system of FMCW radar is designed based on 24 GHz central frequency.In this paper,the radar system is briefly introduced,and the advantages of the FM cw radar system are summarized and analyzed.Next,the research status and background of FMCW radar at home and abroad and the work arrangement of this paper are briefly described.Then,the working principle of FMCW radar and the frequency synthesis scheme of this design are introduced.The main work of this paper:including the transceiver front-end hardware circuit design and software control program design and simulation are described in detail,and then the design of the experimental verification and analysis.The hardware part is divided into two parts: transmitter and receiver.The transmitter part first introduces the performance index of the transmitter hardware circuit and the selection of the transmitter scheme.The transmitter circuit mainly introduces how to use ADF4159 to produce frequency modulation continuous wave and the simulation design of its peripheral filter loop.Then the integrated VCO chip BGT24MTR11 with external PLL is introduced.This kind of chip integrates VCO,frequency divider,power amplifier,power divider,LNA,local oscillator amplification,orthogonal mixing and other basic units.It is suitable for miniaturization design.The receiver part first introduces the receiver receiving scheme selection and the receiver hardware circuit performance index analysis and calculation.Circuits in the receiver module is introduced,the receiver circuit is based on the infineon BGT24MR2 receiving chip(two receiving channels),on the basis of the design of the intermediate frequency modulation circuit,including low noise circuit,orthogonal mixer,a low-pass filter circuit,the gain control amplifier and so on,were introduced and analysis on the operating characteristics of the modules.The software part is mainly the SPI control program of the chip,among which the difficulty focuses on the control of the frequency modulation continuous wave generated by ADF4159.Finally,the hardware was tested.The 24 G FM cw transceiver circuit realized the output of radio frequency signal and local oscillator signal at the central frequency of24.125 GHz and the flatness of the output power within the band was less than 1.8db.Due to the short design time,outdoor ranging and speed measurement were not realized,nor was the transceiver antenna designed,which will be improved in the subsequent work.