CAREER: MEMS Reconfigurable Filters for Multi-Band Low-Power Radios

这项职业计划旨在通过声电放大纳米机械过滤器和3D可调元件的融合，开发用于多频段、多标准无线电的单芯片可重构MEMS过滤器平台。可重构滤波器可以极大地提高射频前端的性能，减小射频前端的体积，因此对频谱进行高效、低功耗的处理受到了极大的关注。尽管目前的可重构滤波器前景看好，但其缺乏集成度和窄频率覆盖范围仍然阻碍了它们在实际应用中的应用。此外，目前的技术未能在不降低损耗、功率处理和终端阻抗等关键性能指标的情况下减小滤波器的尺寸。到目前为止，通用和可重构的滤波阵列平台并不是以单片形式存在的，这是一个重要的问题，尽管MEMS取得了重大进展，但这个问题仍然没有得到解决。该方案解决了与可重构滤波器阵列相关的基本问题，并提出了一种新的技术，通过将窄带声学滤波器与可调集总滤波器相结合来提供频率、带宽和幅度的可调性，这被认为是实现单芯片多频段低功率无线电的最突出的步骤。这种新的方法依赖于声电效应，这是由电子和声子之间相互作用引起的现象。利用这种在纳米尺度上最有效的效应，将开发出一类新型的具有潜在负损耗(即正增益)的纳米机械声滤波器。这将为声学设备和仪器设备带来新的机会。此外，利用先进的3D微机械加工技术，将开发出具有无与伦比的Qs超过150和宽可调范围的微尺度可调块元件。高Q值可调谐无源器件将被用来降低声学滤波器的寄生，并协助调谐其频率响应。PI将利用她之前在高Q无源器件和微制造技术方面的工作来推进这项拟议的研究。除了实验工作，拟议的研究旨在促进科学界-S对支配建议的MEMS阵列性能的物理现象和克服这些物理限制的新技术的理解。广泛的影响：拟议的研究实现了片上可重构的高Q滤波，消除了射频收发器中的许多冗余组件，从而显著减小了外形尺寸并降低了功耗。在蜂窝电话中，使用所提出的技术仅消除一个片外固定频率滤波器以及相关的匹配网络，可将发射印刷电路板面积减少75%以上，同时降低材料成本。因此，拟议的研究将对电信产生变革性的影响。在这项职业计划中开发的可重构MEMS过滤器可能会在无线通信之外具有深远的应用，从医学超声成像到非接触传感。除了概述的研究工作外，还将建立一个综合教育计划，旨在通过直接参与研究活动来教育学生。该项目的外展工作旨在促进工程师和科学家之间的多样性，特别是将工程学领域的女性比例提高到健康水平(30%)。为了实现这一目标，为了激励和教育学生，PI将采取以下方式：(1)通过教育学院向高中教师开展教育外联活动，观察6年级和7年级女生开始对工程学失去兴趣的课堂动态，以及暑期外联计划，通过让高中生参与拟议的研究活动，使他们了解MEMS领域；(2)让未被充分代表的群体的本科生参与Pi？S的研究和教育活动；(3)为学生创建一个多学科的科学学习环境，并培训几名博士生；(4)引入一门新的射频MEMS研究生课程。学生将通过实验室中的团队项目获得研究经验并发现RFMEMS的真实应用；(5)传播本研究的科学成果。

This CAREER proposal aims at the development of a single-chip reconfigurable MEMS filter platformfor multi-band, multi-standard radios through fusion of acoustoelectrically amplified nano-mechanicalfilters and 3D tunable components. Reconfigurable filters can greatly enhance the performance andreduce the size of RF front-ends, and as such have received great attention for effective and low-powerprocessing of the frequency spectrum. Despite their great promise, lack of integration and narrowfrequency coverage of current reconfigurable filters continue to hinder their use in practical applications.In addition, current technologies have failed to reduce the size of filters without deteriorating criticalperformance metrics such as loss, power handling and termination impedance. To-date, a versatile andreconfigurable filter array platform does not exist in monolithic form, an important problem that hasremained unsolved despite major advancement in MEMS. This proposal tackles the fundamental issuesrelated to reconfigurable filter arrays and proposes a novel technique that offers frequency, bandwidth andamplitude tunability through integration of narrow-band acoustic filters with tunable lumped filters.These are believed to be the most prominent steps toward the realization of a single-chip multi-band lowpowerradio.Intellectual merits: The proposed work explores a new approach to developing integrated reconfigurablefilters with wide tuning range and reduced loss. This new approach relies on the acoustoelectric effect, aphenomenon caused by interactions between electrons and phonons. Using this effect, which is mosteffective in nano-scale, a new class of nano-mechanical acoustic filters with potentially negative loss (i.e.positive gain) will be developed. This will yield new opportunities for acoustic devices andinstrumentation. In addition, using advanced 3D micromachining techniques microscale tunable lumpedcomponents with unparalleled Qs exceeding 150 and wide tuning range will be developed. The high-Qtunable passives will be utilized to reduce parasitics of acoustic filters and assist in tuning their frequencyresponse. The PI will leverage her prior work on high-Q passives and micro-fabrication techniquestowards this proposed research. Along with the experimental work, the proposed research aims toadvance the scientific community?s understanding of the physical phenomena that govern theperformance of the proposed MEMS arrays and new technologies that overcome these physical limits.Broader Impact: The proposed research enables on-chip reconfigurable high-Q filtering, eliminatingmany of the redundant components in RF transceivers, which results in drastically smaller form factor andreduced power consumption. In a cellular phone, elimination of only one off-chip fixed-frequency filteras well as the associated matching network using the proposed technique reduces the transmit printedcircuit board area by more than 75%, while lowering the bill-of-materials. As such, the proposed researchwill have transformative impact on telecommunication. The reconfigurable MEMS filters developed inthis CAREER program could have far-reaching applications beyond wireless communication rangingfrom medical ultrasonic imaging to non-contact sensing. In addition to the outlined research effort, anintegrated educational program will be established which aims to educate students through directparticipation in the research activities. The outreach efforts of this project are aimed at promotingdiversity among engineers and scientists and specifically increasing the proportion of women inengineering to a healthy level (30%). To reach this goal and to motivate and educate students, the PIwill pursue the following avenues: (1) Educational outreach through School of Education to high schoolteachers to observe the classroom dynamics in the 6th and 7th grades where female students start to loseinterest in engineering as well as summer outreach programs to expose high school students to the field ofMEMS by involving them in the proposed research activities; (2) Involvement of undergraduate studentsfrom underrepresented groups in PI?s research and educational activities; (3) Creating a multi-disciplinaryscientific learning environment for students and training several doctoral students; (4) Introduction of anew graduate course on RF MEMS. Students will gain research experience and discover real worldapplications of RF MEMS through team projects in a laboratory setting; (5) Dissemination of thescientific results of this research.