Levanon Assaf, Rozban Daniel, Aharon Akram Avihai, Kopeika Natan S, Yitzhaky Yitzhak, Abramovich Amir
Appl Opt. 2014 Dec 20;53(36):8549-55. doi: 10.1364/AO.53.008549.
Millimeter wave (MMW)-based imaging systems are required for applications in medicine, homeland security, concealed weapon detection, and space technology. The lack of inexpensive room temperature imaging sensors makes it difficult to provide a suitable MMW system for many of the above applications. A 3D MMW imaging system based on chirp radar was studied previously using a scanning imaging system of a single detector. The radar system requires that the millimeter wave detector will be able to operate as a heterodyne detector. Since the source of radiation is a frequency modulated continuous wave (FMCW), the detected signal as a result of heterodyne detection gives the object's depth information according to value of difference frequency, in addition to the reflectance of the 2D image. New experiments show the capability of long distance FMCW detection by using a large scale Cassegrain projection system, described first (to our knowledge) in this paper. The system presents the capability to employ a long distance of at least 20 m with a low-cost plasma-based glow discharge detector (GDD) focal plane array (FPA). Each point on the object corresponds to a point in the image and includes the distance information. This will enable relatively inexpensive 3D MMW imaging.
基于毫米波（MMW）的成像系统在医学、国土安全、隐藏武器探测和空间技术等应用中是必需的。缺乏廉价的室温成像传感器使得为上述许多应用提供合适的毫米波系统变得困难。先前使用单个探测器的扫描成像系统研究了基于线性调频雷达的三维毫米波成像系统。该雷达系统要求毫米波探测器能够作为外差探测器工作。由于辐射源是调频连续波（FMCW），外差检测产生的检测信号除了给出二维图像的反射率外，还根据差频值给出物体的深度信息。新的实验表明，使用本文首次（据我们所知）描述的大规模卡塞格伦投影系统能够进行长距离FMCW检测。该系统具有使用低成本的基于等离子体的辉光放电探测器（GDD）焦平面阵列（FPA）实现至少20米长距离检测的能力。物体上的每个点对应于图像中的一个点，并包含距离信息。这将实现相对廉价的三维毫米波成像。
