SHAPE: Dynamic and Reconfigurable Multiband and Ultra-Wideband RF Spectral Tailoring

多频段射频(RF)系统对于商业、国防和日常消费用途至关重要。最近释放了更多的多频段射频资源，用于5G系统等新应用。虽然这些新的发展可能导致有用的新应用得到支持，更多的人能够享受到相关的优势，但只有在我们能够确保高质量的传输性能的情况下，我们才能实现这些好处。这一结果很难实现，因为多频段RF信号的带宽可以达到几千兆赫宽，而当前的电子技术无法动态地操纵如此宽的频谱。这项研究旨在通过利用光子学来克服这一挑战，光子学是一种替代信号处理方法，比电子学中的相应方法具有更宽的带宽和更快的速度。利用所提出的光子学技术，射频信号首先被转换成光学信号，然后可以几乎即时和动态地进行处理。本研究致力于超宽/多频段射频频谱响应的动态精确定制与均衡。我们还将开展与研究密切相关的综合教育计划，包括开发学习光纤的移动应用程序，访问当地的中小学，开展本科新生研讨会和跨学科课程，为高中生和本科生提供研究经验。这项研究将加强美国重要的无线服务，包括智能家居系统控制、增强现实学习以及监视和侦察工作。虽然5G系统等新兴无线技术提供了从MHz到数十GHz的新射频资源，但无法动态和精确地操纵整个可用的射频频谱阻碍了相关多/宽带系统的性能。这项研究的任务是利用光子学来实现对数十GHz宽无线电频谱的有效和精确操纵。提出了两个密切相关的研究主题：(I)开发一种基于光子学的射频频谱整形器，该整形器可以实现数十GHz带宽的连续频谱定制能力，并具有大于50db的动态幅度补偿能力；(Ii)开发一个射频光子子系统，以实现独立的多频段射频频谱整形和啁啾控制。射频频谱整形器利用独特设计的射频多带滤波器的多点频谱控制能力、异质频谱特性控制算法和现有光学设备的瞬时响应来实现从低频段到高频段的动态射频频谱定制。射频频谱的动态频谱处理允许在每个频谱控制点独立控制频率、幅度、频谱形状、带宽和群延迟斜率。这项建议提出了一种全面、跨学科和创新的方法来解决具有挑战性的宽带射频频道响应问题，同时提供了一种单独且精确地定制宽带和多频段射频频谱的解决方案。这项拟议的研究涉及系统设计和实验验证的紧密结合，因此将产生实验室原型，以展示宽带和多频段射频系统的更有效运行。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Multiband radio frequency (RF) systems are essential for commercial, defense, and everyday consumer uses. Further multiband RF resources have recently been released for new applications such as the 5G system. Although these new developments could lead to useful new applications being supported and more people able to enjoy the associated advantages, we can only realize these benefits if we can ensure high-quality transmission performance. This outcome is challenging to achieve because the bandwidth of multiband RF signals can be several gigahertz wide, and current electronic technologies are not capable of dynamically manipulating such a wide spectrum. This research aims to overcome this challenge by making use of photonics, an alternative signal processing method that has much wider bandwidth and faster speed than its counterpart in electronics. With the proposed photonics techniques, the RF signal is first converted to an optical signal, which can then be processed almost instantaneously and dynamically. This research focuses on the dynamic and precise tailoring and equalizing of RF spectral response over ultra-wide/multiple frequency bands. We will also carry out a comprehensive education plan closely related to the research that includes developing mobile apps for learning fiber optics, visiting local elementary and high schools, developing undergraduate freshman seminars and cross-disciplinary courses, and providing research experiences for high school and undergraduate students. This research will strengthen vital wireless services in the United States, including smart home system control, augmented reality learning, and surveillance and reconnaissance efforts.While new RF resources from MHz to tens of GHz have been made available to emerging wireless technologies such as the 5G system, the inability to dynamically and precisely manipulate the whole available RF spectrum hinders the performance of the associated multi-/wideband systems. The mission of this research is to use photonics to enable effective and precise manipulation of wide radio spectrum of tens of GHz. Two closely related research themes are proposed: (i) Developing a photonics-based radio frequency spectrum shaper that can achieve tens of GHz bandwidth of continuous spectral tailoring capability with greater than 50-dB dynamic amplitude compensation, and (ii) Developing a radio frequency photonic subsystem to enable independent multiband RF spectral shaping and chirp control. The radio frequency spectral shaper exploits the multi-point spectral control capabilities of a uniquely designed RF multiband filter, the heterogeneous spectral property control algorithm, and the instantaneous response of existing optical devices to achieve dynamic radio frequency spectrum tailoring from low- to high-frequency bands. The dynamic spectral manipulation of radio frequency spectrum enables independent control of frequency, amplitude, spectral shape, bandwidth, and group delay slope at each spectral control point. This proposal presents a comprehensive, interdisciplinary, and innovative approach to solve the challenging wideband radio frequency channel response problem while offering a solution to individually and precisely tailor the wideband and multiband radio frequency spectrum. The proposed research involves a close coupling of system design and experimental validation, and thus will yield laboratory prototypes to demonstrate more effective operation of wideband and multiband radio frequency systems.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.