Investigations On 77GHz Millimeter-wave Radar System

Millimeter-Wave(MMW)radar has drawn the researches’ attention for its simple system architecture,high integration,excellent resolution and robustness over all different environment.This article designed a FMCW MMW radar and researches on the radar resolution.The main contents as follows:Designed and implemented a 3T4 R FMCW MIMO radar system based on a 77 GHz monolithic integrated radar chip.The system design focuses on phase-locked loops and antenna.To achieve the radar function of target detection,the peripheral circuit was designed,including IF link,FPGA data acquisition and MATLAB algorithm.Additionally,this article verified the frequency division MIMO architecture and MIMO SAR imaging based on this system.The measurement shows that the phase noise of the LO signal locked by the phase-locked loop is relatively low,which is lower than-95 d Bc/Hz@1MHz.The RMS of the sawtooth chirp is 0.025% and the TRx shows high consistency.It was also verified that the system has the azimuth resolution of 9° under MIMO architecture in the target detection of corner reflector.To realize a static 3D imaging radar system,this article designed a 6T8 R FMCW radar system based on the cascade of two MMW radar chips and optimized the antenna array arrangement.The azimuth direction used a 5-antenna element MIMO array,while elevation direction used a 4-antenna element sparse array.The simulated azimuth angle resolution is3.8°,and the elevation resolution is 16°.This radar system board divided into two parts: the RF board and the data acquisition board.It was also verified that the system has the azimuth and elevation angle resolution ability,which is basically the same as the simulation.To increase the SNR of radar receiver,a low noise amplifier with Ga As technology was designed,which bases on a 4-stage cascade negative feedback common source architecture.The measurement results show the gain is larger than 20 dB.