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无法同时实现全景视场和高扫描速度。这是由于来自机械转子或电子移相器的固有硬件延迟，或来自数字信号处理的过多计算时间。通过将成像概念从光学转换为微波，使微波全景相机（MPC）成为可能，可以从根本上克服这些限制。对这种集成的认识和理解将导致一种新的雷达和成像传感器类别，可用于广泛的传感应用。该提议的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的雷达的快速传感速度和全景视野将为驾驶员提供潜在碰撞的早期预警。此外，MPCs的超快帧率将允许通过检测物体的多普勒特征来区分物体。mpc还可以用于需要持续监控路况的自动驾驶系统。这项工作的教育部分将通过吸引底特律地区的社区大学生，将先进的汽车技术融入到本科教育中。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。社区大学的学生，特别是那些来自弱势群体的学生，将被鼓励参加天线和微波工程的研究活动，这对当今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聚焦显微镜（一种基于光纤的高速扫描光学成像方法）转换为微波和毫米波模式。这种集成将使所提出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在线的微波超材料的创建，也称为复合右/左传输线。通过裁剪微波超材料形成频率扫描阵列，可以实现二维频率到空间的映射机制。利用二维角映射方案，结合从反射信号中获得的距离信息，可以得到三维的场景图像。该研究将展示捕获方位和仰角均为180度视场的三维微波图像的能力，帧率速度为1mhz。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可以设计成在多个频段工作，从而可以在雷达系统中执行双频操作，例如24 GHz和77 GHz汽车雷达传感器。

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.