Research And Design Of FMCW Radar Transceiver Front End

Nowadays,with the development of radar technology and the increasing progress of research,the ability of radar to detect targets has gradually become an indispensable technology in various fields such as industrial fields,military applications,and automotive applications.Radar ranging is one of the basic performances of radar.It completes the task of ranging by receiving the echo energy reflected by the illuminated target.The frequency modulation method ranging technology can be applied to continuous wave radar.Frequency Modulated Continuous Wave(FMCW: Frequency Modulated Continuous Wave)radar measures the distance by emitting periodic highfrequency linear frequency ramps to the object.It has large modulation bandwidth and high ranging accuracy,Low probability of interception and other features.Relying on the above advantages,FMCW radar is often referred to as the radar of the future,so this topic mainly focuses on the research and design of the FMCW radar transceiver front end.The transmitter of this subject uses the phase-locked chip LMX2595 to generate a12GHz?13GHz FM continuous wave signal based on double frequency to obtain a FM continuous wave transmission signal with a working frequency band of 24GHz?26GHz.The modulation bandwidth is up to 2GHz,and the frequency sweep period is 4ms,and the measurement distance that can be achieved is 10 m.For the receiving end,the power amplification and cascading two programmable filter circuit processing methods are adopted to perform power amplification,effective filtering and signal gain control on the weak signal at the receiving end.The main advantage of this subject is that the developed FM continuous wave ranging scheme can ensure certain frequency stability and obtain a transmission signal with a large modulation bandwidth on a simple basis,and the accuracy of measuring distance can be improved to a certain extent.The main research contents covered in this topic are:(1)The basic working principle of FMCW radar is theoretically analyzed.Triangular waves are selected as the FM continuous wave transmission signal of the radar,and the working frequency band,sweep frequency and transmission power of the FM continuous wave radar system are theoretically reasoned.(2)Module circuit design at all levels,the main content includes: frequency modulation signal generating circuit,frequency multiplication circuit,receiving intermediate frequency signal amplifying circuit,intermediate frequency signal filtering gain control circuit,chip power supply circuit.(3)Realize program programming and debugging,main content: MCU and phase lock chip LMX2595 carry on serial peripheral device interface protocol(SPI: Serial Peripheral interface)communication to generate triangle wave generation program,intermediate frequency filter circuit cut-off frequency gain control program realization.(4)The physical processing and testing of the FM continuous wave radar transceiver front end have completed the overall performance test and analysis of the FM continuous wave radar radio frequency transceiver front end.