一种高精度的毫米波稀疏平面阵列频域类成像算法

本文以手持式毫米波人体安检设备为研究背景，设计了一种工作于90~94GHz频段的稀疏十字阵列，并采用时域相关算法与改进距离徙动算法（Range Migration Algorithm，RMA）对目标进行成像.针对改进RMA算法在推导过程中存在球面波展开为平面波近似和复杂的插值问题，本文提出一种高精度的无需球面波展开和复杂插值运算的基于（Fast Fourier Transform，FFT）的成像算法，在实现过程中不会引入近似误差和插值误差.采用电磁仿真软件建立目标回波模型，进行测试分辨率和噪声鲁棒性的实验.系统方位分辨率达到5mm，满足系统设计指标要求，验证了所提算法的正确性.综合实验结果得出所提算法的计算效率优于时域相关算法并且噪声鲁棒性优于改进RMA算法，在手持式毫米波人体安检设备实时成像的应用中，所提算法的适用性更好.

A High-Precision Frequency-Domain Imaging Algorithm of Millimeter-wave Sparse Planar Array

Sparse cross array that operating in the 90~94GHz frequency band was designed for the handheld millimeter-wave human body security inspection.The time-domain correlation algorithm and the modified range migration algorithm (RMA)were chosen as image reconstruction methods.Due to the existence of spherical wave expansion approximation and complex interpolation processes in the deriving of the modified RMA algorithm,a high-precision FFT-based imaging algorithm without spherical wave expansion and complex interpolations was proposed.The electromagnetic simulation software was used to build target model obtaining raw echo data,the resolution test and noise robustness verification experiments were carried out.The azimuth resolution can achieve 5mm,which meets the system design requirements,and verifies the effectiveness of the proposed algorithm.The computational efficiency of the proposed algorithm is better than that of the time-domain correlation algorithm and the noise robustness is better than the modified RMA algorithm.It can be concluded that the proposed algorithm is a better choice in real-time imaging scenarios of the handheld millimeter-wave human body security inspection.