Research On Design And Algorithm Of Frequency Modulated Continuous Wave Synthetic Aperture Radar System

Because of its long signal duration and duty cycle of 1,FM continuous-wave radar no longer requires high peak transmit power compared to traditional pulse radar,which greatly reduces the design difficulty of radar transmitters,while FMCW radars are The de-frequency modulation mechanism is adopted during reception,which reduces the bandwidth of the data and reduces the difficulty of sampling and processing the radar data.This makes the FMCW radar system has the advantages of small size,light weight,and simple structure,and can be used with more carriers.Adapting the platform is one of the best choices for small UAV airborne radars.At the same time,the combination of frequency modulated continuous wave radar technology and synthetic aperture technology will make the radar system not only have the above advantages,but also have high resolution and have a very wide range of application prospects.This article is a combination of software and hardware,including radar system,antenna design and algorithm research and implementation,the use of the radar system actually collected target data for algorithm processing,reflecting the performance of the system,verifying the feasibility of the algorithm.The specific content includes the following aspects:1.Describes the principle of FMCW SAR,including radar frequency measurement method and synthetic aperture principle,and introduces the principle of de-frequency modulation,which explains why radar obtains high range and azimuth resolution.The calculation formulas for distance and azimuth resolution are given.2.A FMCW SAR system is designed and implemented,which includes the design and analog circuit design of the radar transmitter and receiver scheme,as well as the selection of parameters of the RF and lumped components,and the estimated power of the radar transmitter output signal.3.A wideband microstrip antenna array suitable for frequency-modulated continuous-wave synthetic aperture radar systems was designed and implemented.Several schemes for broadening the antenna bandwidth and reducing the antenna size were proposed and compared using HFSS.After comparison,the L-type was selected.The probe-fed air box dielectric microstrip antenna array is used as a radar antenna,which has the characteristics of small volume,high bandwidth,good gain,and low cost.4.The radar algorithm is studied,the concept of distance migration in synthetic aperture imaging is introduced,and the principles and steps of distance migration(RMA)imaging algorithm are described.5.Using the designed system to measure data collected from different targets,radar speed measurement,distance measurement,and imaging experiments were performed to verify the feasibility of the algorithm and test the performance of the radar system.The speed measurement experiment shows that the system can accurately measure the radial velocity of a single target.The distance measurement experiment shows that the system can measure the distance between the moving target and the static target distance radar.The imaging experiment shows that the system can measure the coordinate information of the target more accurately.