Low Noise, Tunable Non-Reciprocal RF Front-Ends Based on Time-Varying Transmission Lines (TVTL)

基于时变传输线 (TVTL) 的低噪声、可调谐非互易 RF 前端

• 批准号: 1610594
• 负责人: Yuanxun Wang
• 金额: $ 30万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1610594&HistoricalAwards=false
• 关键词: Low; Noise; Tunable; Non; Reciprocal

A transmission line structure with its effective dielectric property modulated in space and time is proposed. Such a transmission line supports two-way propagation of electromagnetic waves on the same structure while keeping the electromagnetic waves propagating toward different directions separatable by shifting only the frequency of the wave that aligns with the direction of the space-time modulation. Leveraging both on the fundamental science of radio frequency circuits and the modern semiconductor technology, the proposed concept will find a broad range of applications in modern wireless systems by creating novel radio frequency devices and functional blocks that enables sensitive and interference resilient wireless front-ends. The proposed work fosters interactions among multiple engineering research fields. If successful, it will revolutionize the current way of transmitting and receiving electromagnetic waves in a challenging environment and lead to next generation communication or sensor electronics that are of low power consumption, high performance, compact and affordable. As the advancement of mobile communication technology is changing human lifestyle, a high performance wireless radio frequency front-end will provide a great thrust to this change.This proposal is to attack the noise and interference issues in the radio frequency front-end that fundamentally limits of the performance of a wireless system, by developing tunable, non-reciprocal front-ends with broad frequency tunability yet low noise. Such a front-end is only enabled through exploiting the unique property of Time-Varying Transmission Line. Time-varying transmission line consists of passive transmission lines whose inductance or capacitance is space-time modulated by another electromagnetic wave. It possesses a mixture of passive and active circuit characteristics. First, it is a transmission line that can be engineered and designed to have accurate impedance, phase and delay characteristics in both directions. Furthermore, it offers functions of active circuits such as amplifications and frequency conversions. Devices created out of this novel concept include resonators with accurately controlled resonating frequency yet allowing resonances across different frequencies to couple. This property can be utilized to create low noise, high-quality factor, tunable filtering capability even within miniaturized dimensions. The proposed effort will first establish a systematic theory of Time-Varying Transmission Line being used as a key building block to achieve superior performance in radio frequency front-ends. This includes various novel developments of functional blocks such as circulators, tunable filters with parametrically enhanced quality factors, low noise amplifiers, active frequency conversion and phase shifting circuits. Modern semiconductor technology will then be utilized for on-chip integration of the proposed devices. The performance bound on practical implementations of the radio frequency front-end will be derived based on these integrated circuit prototypes. Ultimately, new wireless system architectures and applications that fully leverage on the unique features of these devices will be explored for the purpose of meeting the need of emerging wireless communications.

提出了一种在空间和时间上调制有效介电特性的传输线结构。这种传输线支持电磁波在同一结构上的双向传播，同时通过仅移动与时空调制方向一致的波的频率来保持向不同方向传播的电磁波可分离。利用射频电路的基础科学和现代半导体技术，所提出的概念将通过创建新颖的射频器件和功能块来实现灵敏且抗干扰的无线前端，从而在现代无线系统中得到广泛的应用。拟议的工作促进了多个工程研究领域之间的相互作用。如果成功，它将彻底改变当前在充满挑战的环境中发射和接收电磁波的方式，并带来低功耗、高性能、紧凑且价格实惠的下一代通信或传感器电子产品。移动通信技术的进步正在改变人类的生活方式，高性能的无线射频前端将为这一变化提供巨大的推力。该提案旨在解决射频前端的噪声和干扰问题，从根本上限制了无线射频前端的性能。通过开发具有宽频率可调性和低噪声的可调非互易前端，可以提高无线系统的性能。这样的前端只能通过利用时变传输线的独特属性来实现。时变传输线由无源传输线组成，其电感或电容受到另一种电磁波的时空调制。它具有无源和有源电路特性的混合。首先，它是一种可以在两个方向上具有精确阻抗、相位和延迟特性的传输线。此外，它还提供有源电路的功能，例如放大和频率转换。根据这一新颖概念创建的设备包括具有精确控制谐振频率但允许跨不同频率的谐振耦合的谐振器。即使在微型尺寸内，也可以利用该特性来创建低噪声、高质量因数、可调谐滤波能力。 拟议的工作将首先建立时变传输线的系统理论，将其用作实现射频前端卓越性能的关键构建块。这包括功能块的各种新颖开发，例如循环器、具有参数增强品质因数的可调谐滤波器、低噪声放大器、有源频率转换和相移电路。然后，现代半导体技术将用于所提议器件的片上集成。射频前端实际实现的性能限制将基于这些集成电路原型得出。最终，将探索充分利用这些设备独特功能的新无线系统架构和应用，以满足新兴无线通信的需求。