GOALI: Transparent Beam Steering Antennas Enabled by Graphene Quantum Capacitance Varactors

该项目旨在创造一种革命性的透明波束转向天线技术，用于自动驾驶汽车。该项目采用人工阻抗表面天线，由于其成本低，设计简单，非常适合集成到汽车车窗玻璃中。关键的创新是利用纳米材料石墨烯创造了一个可变电容调谐元件，可以直接集成到天线上，在保持高性能和透明度的同时实现波束控制。这项工作将导致对石墨烯变容管的性能限制以及新型天线设计和操作的新的基本理解。它将提供对石墨烯器件频率限制的新理解，并可能为透明、可操纵天线的新设计概念打开大门。该项目还将推进一项对国家至关重要的技术，该技术有可能最大限度地减少与交通有关的死亡，减少温室气体排放，使视力受损的人拥有前所未有的机动性，减少交通拥堵，并提高企业生产力。该项目还将提供一个理想的推广活动平台，与工业互动提供了一个自然的方式来教育研究生毫米波组件的汽车应用。该项目还将有助于将石墨烯纳入明尼苏达大学的本科电气工程课程，并提供一个结合固态器件和电磁学方面的跨学科问题的极好例子。此外，将开发K-12教育项目，包括以石墨烯为基础的实践活动，以及有关自动驾驶汽车和汽车安全的信息。该项目将探索创造一种变革性技术，将石墨烯可变电容器（变容体）直接集成到人工阻抗表面上，使波束转向天线能够在毫米波频率下工作。该项目集成了两种迄今为止从未结合过的技术：(1)人工阻抗表面天线，由于其简单的设计，具有低成本和波束转向能力的巨大潜力；(2)石墨烯变容管，它提供了一种优雅的方法来整合波束转向的调谐元件，而且是透明的。研究范围和方法包括以下几个方面。将开发一种新的短通道长度石墨烯变容管制造工艺，以实现毫米波频率下的高速运行。还将开发一种工艺，将石墨烯变容管与人工阻抗表面天线单片集成，以创建可操纵天线。最后，透明天线将使用金属网格策略制造和表征，并将其性能与不透明天线进行比较。该项目的智力意义在于，它将导致对高速石墨烯器件和天线技术的基本理解。将探索石墨烯变容管在毫米波频率下的性能极限，以更宽的调谐范围、更高的品质因数和更好的均匀性推进该技术。将创建毫米波频率波束转向天线的新集成平台，与传统方法相比，该平台具有增强性能的潜力，并有望在自动驾驶汽车中实现实际应用。

The project intends to create a revolutionary transparent beam-steering antenna technology for use in self-driving vehicles. The project utilizes the artificial impedance surface antenna which is ideally suited for integration into automobile window glass due to its low cost and simple design. The key innovation is to utilize the nanomaterial graphene to create a variable capacitance tuning element that can be integrated directly onto the antenna to enable beam steering while maintaining high performance and transparency. This work will lead to a new fundamental understanding of both the performance limits of graphene varactors as well as the novel antenna design and operation. It will provide new understanding of the frequency limits of graphene devices, and could open the door to new design concepts for transparent, steerable antennas. The project will also advance a technology of vital national importance that has the potential to minimize traffic-related deaths, reduce greenhouse gas emissions, enable unprecedented mobility for vision-impaired individuals, reduce traffic congestion, and improve business productivity. The project will also provide an ideal platform for outreach activities, with the industrial interaction providing a natural means to educate graduate students on the automotive applications of millimeter-wave components. This program will also aid in the incorporation of graphene into the undergraduate electrical engineering curriculum at Minnesota, and provides an excellent example of a cross-disciplinary problem, incorporating aspects of solid-state devices and electromagnetism. In addition, K-12 educational programs will be developed that include graphene-based hands-on activities as well as information about self-driving vehicles and automobile safety.This project will explore the creation of a transformative technology where graphene variable capacitors (varactors) are directly integrated onto artificial impedance surfaces to enable beam steering antennas operating at millimeter-wave frequencies. The project integrates two technologies that, to date, had not been previously combined: (1) artificial impedance surface antennas which have great potential for low cost and beam steering capabilities due to their simple design and (2) graphene varactors, which provide an elegant method to incorporate tuning elements for beam steering and are also transparent. The research scope and methods include the following aspects. A new fabrication process for short-channel-length graphene varactors will be developed to enable high-speed operation at millimeter-wave frequencies. A process will also be developed to monolithically integrate graphene varactors with artificial impedance surface antennas to create steerable antennas. Finally, transparent antennas will be fabricated and characterized using a metal meshing strategy and their performance will be compared to opaque antennas. The intellectual significance of this project is that it will lead to a fundamental understanding of high-speed graphene device and antenna technology. It will explore the performance limits of graphene varactors at millimeter-wave frequencies, and advance the technology with wider tuning range, higher quality factor, and improved uniformity. A new integrated platform for beam steering antennas at millimeter-wave frequencies will be created, with the potential for enhanced performance compared to conventional approaches and a path toward practical implementation in autonomous vehicles.