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

无线通信在世界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性增长，以及预计会出现传感器群和物联网等新型网络，目前获得许可的频谱访问模式似乎越来越不可行。目前正在积极研究两种互补的解决方案：(1)频谱共享认知无线电和(2)基于密集、短距离毫米波链路的无线网络。开发高度可重新配置、高能效的无线电对这些技术的长期成功至关重要。该方案通过开发灵活、频谱纯净和可重新配置的“通用”频率合成器的设计技术，解决了一个关键的电路级挑战。智能优点：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的模拟缺陷不那么敏感，具有高度的可重构性，可以快速移植到技术节点上，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-数字转换器的设计以及两者之间的接口设计对全数字频率合成器的成功实现构成了障碍。提出了几个新的概念和技术来应对这些挑战。其中包括多谐振模式切换和相变通孔可重配置振荡器、具有现场统计线性化的时间-数字转换器、为合成器的模拟组件提供实时数字辅助以及内置监控、自适应和自检电路。为了验证这些概念，我们将设计和制造一个cmos原型。更广泛的影响这项研究的结果将填补在使用先进的频谱接入技术的未来无线系统中实现实用设备的关键需求。结果还将满足构成试点试验台基础的原型的紧迫近期需求。这项建议的教育部分包括科学出版物、公共关系、指导和通过CMU Gelfand服务学习和外联中心实施的各种方案进行的外联；这些方案包括为中学女生提供的进入工程和暑期工程体验的Moving Fourth方案，以及其他针对妇女和其他代表性不足群体的外联方案。这项研究的成果将被整合到国际学生联合会教授的各种课堂中。将开发一门新的混合信号集成电路设计顶峰课程。PI将继续通过卡内基梅隆大学的暑期研究体验计划招募和培训本科生，特别注重吸引少数族裔群体和机构的学生。

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.