Reconfigurable All-Digital CMOS Frequency Synthesizers for Cognitive and Milimeter-Wave Radios

无线通信在全球范围内产生了不可估量的经济、社会和科学影响。然而，随着最近智能手机和平板电脑的爆炸式增长，以及传感器群和物联网等新型网络的预期出现，目前许可接入频谱的模式似乎越来越不可行。目前正在积极研究两种互补解决方案：（1）频谱共享认知无线电和（2）基于密集短程毫米波链路的无线网络。高度可重构、功率高效的无线电设备的开发对于这些技术的长期成功至关重要。该提案通过开发敏捷、频谱纯净和可重构的“通用”频率合成器的设计技术，解决了关键电路级的挑战。智力优势：与当前无线电中常用的基于模拟的频率合成器相比，全数字频率合成器对纳米级CMOS的模拟缺陷不太敏感，具有高度可重构性，并且可以跨技术节点快速移植，因此是通用频率合成的有前途的候选者。 然而，宽调谐振荡器、高分辨率/高线性度时间数字转换器以及两者之间的接口的设计对全数字频率合成器的成功实现构成了障碍。提出了一些新的概念和技术来应对这些挑战。这些包括多谐振模式切换和相变通过可重构振荡器，时间数字转换器与现场统计线性化，实时数字辅助合成器的模拟组件和内置的监控，自适应和自检电路。一个CMOS原型将被设计和制造，以验证这些概念。更广泛的影响这项研究的成果将满足实现实用设备的关键需求，用于使用先进的频谱接入技术的未来无线系统。这些成果还将满足对形成试点测试平台基础的原型的紧迫近期需求。该提案的教育组成部分包括科学出版物，公共关系，指导和通过CMU Gelfand服务学习和外展中心开展的各种方案进行的外展;这些方案包括在中学课程中为女孩提供的第四次进入工程和夏季工程体验以及为妇女和其他代表性不足的群体提供的其他外展方案。这项研究的成果将被纳入PI教授的各种课程。一个新的顶点课程混合信号集成电路设计将开发。PI将继续通过卡内基梅隆大学夏季研究体验计划招募和培训本科生，特别注重吸引来自少数群体和机构的学生。

Wireless communication has had an immeasurable economic, societal and scientific impact worldwide. However, with the recent explosion of smartphones and tablets, and the expected emergence of new types of networks such as sensor swarms and the internet of things, the current model of licensed access to spectrum being appears increasingly unviable. There is currently active research into two complementary solutions: (1) spectrum sharing cognitive radios and (2) wireless networks based on dense, short-range millimeter-wave links. The development of highly reconfigurable, power-efficient radios is critical to the long term success of these technologies. This proposal addresses a critical circuit-level challenge by developing design techniques for agile, spectrally pure and reconfigurable "universal" frequency synthesizers. Intellectual Merit: Compared to analog-based frequency synthesizers commonly used in current radios, all-digital frequency synthesizers are less sensitive to the analog-imperfections of nanoscale CMOS, are highly reconfigurable and can be rapidly ported across technology nodes, and are therefore promising candidates for universal frequency synthesis. However, the design of widely tunable oscillators, high-resolution/high-linearity time-to-digital converters and the interface between the two pose obstacles to the successful realization of all-digital frequency synthesizers. Several new concepts and techniques are proposed to address these challenges. These include multi-resonance mode switched and phase-change via-reconfigurable oscillators, time-to-digital converters with in situ statistical linearization, real-time digital assistance for the analog components of the synthesizer and built-in monitoring, adaptation and self-test circuitry. A CMOS prototype will be designed and fabricated to validate these concepts. Broader Impact The outcomes of this research will fill a critical need towards the realization of practical devices for use in future wireless systems using advanced spectral access technologies. The outcomes will also fill a pressing near-term need for prototypes that form the basis of pilot testbeds. The educational components of this proposal include scientific publications, public relations, mentoring, and outreach through various programs conducted by the CMU Gelfand Center for Service Learning and Outreach; these programs include the Moving 4th into Engineering and Summer Engineering Experience for girls in middle school programs and other outreach programs for women and other underrepresented groups. The outcomes of this research will be integrated into various classes taught by the PI. A new capstone course on Mixed-Signal Integrated Circuit Design will be developed. The PI will continue to recruit and train undergraduate students through the the Summer Research Experience Program Carnegie Mellon, with a special focus on attracting students from minority groups and institutions.