CAREER: Spectrally-Encoded Ultrafast Microwave Panoramic Camera

目前使用传统波束扫描技术的微波雷达系统不能同时实现全景视场（FOV）和高扫描速度。这是由于来自机械转子或电子移相器的固有硬件延迟，或者来自数字信号处理的过多计算时间。 这些限制可以通过将成像概念从光学转换为微波来根本克服，从而实现微波全景相机（MPC）。这种集成的知识和理解将导致一个新的类别的雷达和成像传感器，可用于广泛的传感应用。建议的MPC将特别应用于汽车雷达，以提供驾驶员辅助，使驾驶更安全，更方便。 基于MPC的雷达实现的快速感应速度和全景FOV将为驾驶员提供潜在碰撞的早期预警。此外，MPC的超快帧速率将允许通过检测它们的多普勒特征来区分对象。 通过全景FOV，MPC还可用于需要持续监控路况的自动驾驶系统。 拟议工作的教育部分将通过吸引底特律大都会地区的社区大学生，将先进的汽车技术融入本科教育。 它将通过密歇根州国王查韦斯公园（KCP）倡议的大学绑定计划进行。 社区学院的学生，特别是那些来自代表性不足的群体，将被鼓励参加天线和微波工程的研究活动，对今天的汽车雷达成像传感器和远程信息处理至关重要。本研究的目的是将光谱编码共焦显微镜，一种基于光纤的光学成像方法，用于高速扫描，到微波和毫米波制度。这种集成将使拟议的微波全景相机具有超快的扫描速度和全景视野。该技术方法依赖于基于传输线的微波超材料的创建，也称为复合右/左手传输线。通过剪裁微波超材料形成频率扫描阵列，可以实现二维频率-空间映射机制。 利用二维角度映射方案沿着从反射信号获得的距离信息将导致三维场景的图像。 这项研究将展示以1 MHz的帧率捕获方位角和俯仰角均为180度视野的三维微波图像的能力。 快速的帧刷新率将允许捕获移动物体的任何多普勒和微多普勒效应，并将其用于目标识别和识别。此外，通过设计微波超材料的色散特性，所提出的MPC可以被设计为在多个频带中工作，使得为雷达系统（例如24 GHz和77 GHz汽车雷达传感器）执行双频操作成为可能。

Current microwave radar systems using conventional beam scanning techniques cannot simultaneously achieve a panoramic field of view (FOV) and high scanning speed. This is due to intrinsic hardware latencies from mechanical rotors or electronic phase shifters, or excessive computation time from digital signal processing. These limitations can fundamentally be overcome by transforming imaging concepts from optics into microwaves, enabling a microwave panoramic camera (MPC). The knowledge and understanding of such integration will lead to a novel category of radars and imaging sensors that can be used for a wide range of sensing applications. The proposed MPC will be applied, in particular, to automotive radar to provide driver assistance, making driving safer and more convenient. The fast sensing speed and panoramic FOV enabled by MPC-based radars will provide early warning of potential collisions to drivers. Furthermore, the ultrafast frame rate of MPCs will allow differentiation of objects by detecting their Doppler signatures. With a panoramic FOV, MPCs can also be used in autonomous driving systems requiring constant monitoring of road situations. The educational component of the proposed work will integrate advanced automotive technologies into undergraduate education by engaging community college students in the Metro Detroit area. It will be conducted through the University Bound Program, a State of Michigan King-Chavez-Parks (KCP) Initiative. Community college students, especially those from underrepresented groups, will be encouraged to participate in research activities in antenna and microwave engineering essential for today's automotive radar imaging sensors and telematics. The objective of this research is to transform spectrally encoded confocal microscopy, a fiber-based optical imaging method for high-speed scanning, into the microwave and millimeter-wave regime. This integration will enable the proposed microwave panoramic camera with ultrafast scanning speed and a panoramic field of view. The technical approach relies on the creation of transmission-line based microwave metamaterials, also known as composite right/left-handed transmission lines. By tailoring microwave metamaterials to form a frequency scanned array, a two-dimensional frequency-to-space mapping mechanism can be realized. Utilizing the two-dimensional angular mapping scheme along with the range information obtained from the reflected signal will result in an image of the scene in three dimensions. This research will demonstrate the capability to capture a three-dimensional microwave image with 180-degree FOV in both azimuth and elevation, with a frame-rate speed of 1 MHz. The fast frame refresh rate will allow any Doppler and micro-Doppler effects of moving objects to be captured and exploited for target recognition and identification. Furthermore, by engineering the dispersion characteristics of microwave metamaterials, the proposed MPC can be designed to work in multiple bands, making it feasible to perform dual-band operations for radar systems, such as 24 GHz and 77 GHz automotive radar sensors.