Journal Article

Applicable Near-Field Millimeter Wave Imaging Technology for Human Body Security Based on Scanning 1D Non-uniform Sparse Arrays

Zhang, Huakun, An, Deyue, Zhu, Lian, Tu, Hao

2025

Overview

Employing a sparse array is an effective method to reduce the cost of millimeter wave (MMW) imaging systems. However, the sparse array can lead to uneven MMW sampling along the array dimension, which renders the highly efficient range migration algorithm (RMA) inapplicable. While the back projection algorithm (BPA) can meet the needs of uneven sampling, its efficiency is too low. Therefore, this paper proposes a novel MMW image reconstruction algorithm, named range migration and back projection algorithm (RMBPA), which combines RMA and BPA. The RMBPA uses the RMA for focusing and solving in the mechanically scanned and range-focused directions with uniform sampling and employs the BPA for aperture synthesis in the direction with non-uniform sampling. Building upon the RMBPA, this paper introduces an innovative low-cost planar scanning MMW imaging technology based on a one-dimensional (1D) sparse array. Simulation and experimental results demonstrate that the imaging technology can achieve a spatial resolution of 5 mm in the Ka-band, clearly discerning the human silhouette and handgun model in human body imaging. The image quality is comparable to that of non-sparse array imaging under the same conditions, with imaging efficiency slightly lower than RMA but significantly higher than BPA. The technology can get a 1 m × 2 m area imaging in only 2.0 s, offering significant application value.

• Publisher: Springer US,Springer Nature B.V
• Subject: Algorithms / Arrays / Classical Electrodynamics / Electrical Engineering / Electronics and Microelectronics / Engineering / Extremely high frequencies / Human body / Image quality / Image reconstruction / Instrumentation / Millimeter waves / Sampling / Spatial resolution