基于FMCW环扫SAR的成像系统设计及测试方法

Design and testing method of imaging system based on FMCW circular scanning SAR

为实现目标不同距离的高分辨率成像,提出一种调频连续波(FMCW)环扫合成孔径雷达(SAR)体制下的目标距离向探测系统设计及测试方法。该系统由模拟前端和FPGA共同处理实现,设计多种工作模式以实现近、中、远3种探测距离及相应的分辨率。通过MATLAB模拟射频前端去调频处理后的信号,加载到FPGA数字下变频处理,对所得信号仿真得到输出频谱,并进行闭环板级实测,验证了该基于FMCW环扫SAR的目标距离向成像系统设计的可行性。

In order to achieve high resolution imaging with different distances, a target range direction detection system is designed and tested under the frequency modulated continuous wave（ FMCW） circular scanning synthetic aperture radar（ SAR） system. The system is realized by analog front end and FPGA, and various working modes are designed to realize three detecting ranges and corresponding resolutions in the near, middle and far distance. Through MATLAB the RF front-end de-chirped signals are simulated,loaded into the FPGA digital down conversion processing, and emulated to get output spectrum. Closed-loop board level measurement is carried out, and the feasibility of the target range direction imaging system is verified based on FMCW circular scanning SAR.