Breaking the Barrier for Acoustic Resonators: High Performance Filters at Millimeter Waves

毫米波通信标准旨在通过促进增强和虚拟现实、无人驾驶飞行器和自动驾驶汽车、远程健康和基础设施监控以及更广泛的物联网的高速数据链路来彻底改变社会。正在商业化的毫米波系统不依赖于天线元件处的滤波。可以预见的是，随着部署的系统数量的增加，干扰器以及因此缺乏滤波将成为这些通信系统的瓶颈，导致基带电子设备的大功耗。随着越来越多的毫米波系统被部署，频谱变得越来越拥挤，将需要增加功耗来处理干扰信号。通过天线元件处的毫米波滤波消除干扰的需求将成为进一步部署这些网络的根本瓶颈。在片上/便携式/可穿戴设备所需的形状因子中，在这些频率处的带通滤波器的设计和实现特别具有挑战性。该研究项目建议使用声学元件直接在每个天线元件处提供尖锐滤波。如果成功，该项目将产生超出本文提出的特定毫米波应用的更广泛影响。通过克服与毫米波声谐振器的设计和合成相关的基本挑战，研究工作将设计一个通用的谐振器平台，用于研究与量子信息科学相关的其他现象，将声谐振器的操作范围扩展到毫米波频率伴随着与以低损耗在这样的高频率下操作的能力相关的基本问题，适当的阻抗水平。在毫米波下获得高性能是声学器件的基本障碍。解决这些问题需要对材料、纳米纤维工艺和谐振器设计进行调查，这些都是对声学设备最新技术的挑战。这项工作的智力价值在于：调查基本的阻尼机制，在薄膜中的悬浮结构在毫米波;设计创新的谐振器设计，最大限度地减少阻尼，同时保持谐振器的特性阻抗匹配;和开发nanofabstraction的方法，使纳米尺度的功能与微米级结构的共存与高产率。该项目的最终应用目标是设计一种在毫米波下工作的带通滤波器，该滤波器使用以传统梯形配置排列的声谐振器集合。该项目还研究了用于产生两个近频谐振器和实时调谐滤波器带宽的各种新技术。该奖项反映了NSF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。

Communication standards at millimeter waves are meant to revolutionize society by facilitating high speed data links for augmented and virtual reality, unmanned air vehicles and self-driving cars, remote health and infrastructure monitoring, and the broader Internet of Things. The millimeter wave systems that are being commercialized do not rely on filtering at the antenna element. It is predictable that as the number of deployed systems will increase, interferers and hence the lack of filtering will be a bottleneck for these communication systems, resulting in large power consumption by the baseband electronics. As more millimeter wave systems are deployed, and the spectrum is getting congested, increase power consumption will be required to handle interfering signals. The needs to eliminate interferers through mm-wave filtering at the antenna element will become a fundamental bottleneck to further deployment of these networks. The design and implementation of bandpass filters at these frequencies in the form factors required by on-chip/portable/wearable devices is particularly challenging. This research project proposes to use acoustic elements to deliver sharp filtering directly at each antenna element. If successful, this project will have broader impacts beyond the specific millimeter wave applications proposed herein. By overcoming the fundamental challenges associated with the design and synthesis of millimeter wave acoustic resonators, the research effort will devise a general resonator platform for investigating other phenomena associated with quantum information science, computing and sensing.Extending the range of operation of acoustic resonators to millimeter wave frequencies comes with fundamental questions related to the ability to operate at such high frequency with low loss and appropriate impedance levels. Attaining high performance at millimeter waves is a fundamental barrier for acoustic devices. Answering these questions calls for investigations into materials, nanofabrication processes and resonator designs that challenge the state-of-the-art in acoustic devices. The intellectual merit of this work consists in: investigating fundamental damping mechanisms in thin films of suspended structures at millimeter waves; devising innovative resonator designs that minimize damping while preserving resonator characteristic impedance matching; and developing nanofabrication methods that enable the co-existence of nanoscale features with micron-scale structures with high yields. The ultimate applied goal of this project is to devise a bandpass filter operating at millimeter waves using an ensemble of acoustic resonators arranged in a conventional ladder configuration. This project is also investigating various novel techniques for generating two nearby-frequency resonators and for real-time tuning of the filter bandwidth.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.