ERI: Low-Cost, Miniaturized, Wideband and Wide-Angle Beam Steering Array For 5G Communication System

蜂窝系统正转向毫米波频段，因为可用带宽更宽，数据速率更高；然而，这些系统遭受严重的传播损失、信号阻塞和衰落效应；因此，第五代（5G）基站很难同时有效覆盖室外环境和室内场景。需要宽带和高分辨率波束导向来确保一致的连接，这对于5G以外的许多应用来说是一个关键因素，例如车对车通信、汽车雷达、遥感和卫星通信。本提案将开发一种k波段混合波束形成系统，该系统由双极化低轮廓天线阵列和基于次谐波混合相移的模拟波束形成机制组成。除了技术效果外，该项目还将通过支持跨学科劳动力发展和扩大来自不同背景的个人参与STEM来影响教育。该项目将促进推广活动，包括每年为奥克兰大学工程项目的高中生和女孩举办的夏令营，并让更多的本科生参与研究。本提案将开发一种由天线阵列和调频连续波束形成机制组成的k波段混合波束形成系统，从而实现低成本、小型化的解决方案，以满足多径效应和动态需求等复杂通信环境问题。具体而言，将追求以下创新：a)将开发基于k波段的混频移相，以获得低幅度变化，同时在较低频率使用低成本移相器。这些系统的主要部件是滤波器、功率分配器、移相器、本振器和天线阵列。在较低的频率下进行相移使实现更简单，并且有更多的技术可用。该系统将使用PCB技术实现，并将与最先进的5G毫米波相控阵（集成电路级）进行关键性能参数的比较。(b)为了实现极化分集和波束扫描能力，将使用垂直极化和水平极化天线实施和演示双极化。水平和垂直极化天线将集成到一个区域，而不需要任何多层PCB来实现。漏波天线也将被开发以进一步简化馈电网络。(c)将探索非线性传输线（NLTL）作为相控阵馈电网络的控制器，以实现更高带宽的波束转向。单片制造的NLTL将提供较小的单元长度和平均电容。不同的NLTL电路将使用解析解、电路模拟和实验表征来呈现。一旦完成，所开发的架构可以适应广泛的可控制频率范围，只需最小的电路更改，同时提供高分辨率，提高副瓣和零区抑制水平，并提高波束指向精度。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cellular systems are shifting to mm-Wave frequency bands because of wider available bandwidth and high data rates; however, these systems suffer from severe propagation losses, signal blockage, and fading effects; therefore, it is difficult for the fifth generation (5G) base station to cover both the outdoor environment and indoor scenario effectively. Wideband and high-resolution beam-steering is needed to ensure consistent connectivity and it is a crucial factor for many applications beyond 5G, such as vehicle-to-vehicle communication, automotive radars, remote sensing, and satellite communications. This proposal will develop a K-band hybrid beamforming system comprised of dual-polarized low-profile antenna arrays and an analog beamforming mechanism using a subharmonic mixing-based phased shifting. In addition to the technical effects, the project will also impact education by supporting interdisciplinary workforce development and broadening participation in STEM for individuals from diverse backgrounds. The project will facilitate outreach activities, including annual summer camps for high school students and girls in the engineering program at Oakland University, and involve more undergraduate students in the research.This proposal will develop a K-band hybrid beamforming system comprised of the antenna array and frequency-modulated continuous (FMCW) beamforming mechanism, resulting in a low-cost, miniaturized solution to fulfill complex communication environment problems such as multi-path effects and dynamic demands. To be specific, the following innovations will be pursued: a) Frequency mixing-based phase shifting at K-band will be developed to obtain low-magnitude variation while using lower-cost phase shifters at lower frequencies. The main components in these systems are filters, power splitters, phase shifters, Local oscillators, and antenna arrays. Doing phase shifting at a lower frequency makes the implementation simpler, and more techniques are available. The proposed system will be implemented using PCB technology and will be compared with the state-of-the-art 5G millimeter-wave phased array (integrated circuit level) for key performance parameters. (b) To achieve polarization diversity and beam-scanning capability, dual-polarization will be implemented and demonstrated using a vertically polarized and horizontally polarized antenna. The horizontally and vertically polarized antennas will be integrated into a single area without needing any multilayer PCB for implementation. Leaky-wave antennas will also be developed to simplify the feeding network further. (c) Non-Linear Transmission Line (NLTL) will also be explored as a controller in the feeding network of phased array antennas to achieve beam steering with higher bandwidths. Monolithically fabricated NLTL will provide small unit-cell lengths and average capacitances. Different NLTL circuits will be presented using analytical solutions, circuit simulations, and experimental characterization. Once completed, the developed architecture can be adapted to an extensive range of steerable frequencies with minimal circuit change while providing high resolution, improved sidelobe and null-area rejection levels, and improved beam-pointing accuracy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.