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.

提出了一种有效介电特性在空间和时间上可调的传输线结构。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的方向对准的波的频率来保持朝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，实现灵敏和抗干扰的无线前端，在现代无线系统中找到广泛的应用。拟议的工作促进多个工程研究领域之间的互动。如果成功，它将彻底改变目前在具有挑战性的环境中发送和接收电磁波的方式，并导致下一代通信或传感器电子产品具有低功耗，高性能，紧凑和负担得起的特点。随着移动的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动力，本方案通过开发具有宽频率可调谐性和低噪声的可调谐非互易前端来解决射频前端中的噪声和干扰问题，这些问题从根本上限制了无线系统的性能。这种前端只能通过利用时变传输线的独特属性来实现。时变传输线是指电感或电容受另一电磁波时空调制的无源传输线。它具有无源和有源电路特性的混合。首先，它是一种传输线，可以被工程和设计为在两个方向上具有精确的阻抗，相位和延迟特性。此外，它还提供了有源电路的功能，如放大和频率转换。由这种新颖概念产生的设备包括具有精确控制的谐振频率的谐振器，还允许跨不同频率的谐振耦合。该特性可用于创建低噪声、高品质因数、可调谐滤波能力，甚至在小型化尺寸内。 本论文将首先建立一套系统的时变传输线理论，作为射频前端实现上级性能的关键构件。这包括功能块的各种新开发，例如循环器、具有参数增强的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。现代半导体技术将被用于所提出的器件的片上集成。将根据这些集成电路原型推导出射频前端实际实现的性能约束。最终，新的无线系统架构和应用程序，充分利用这些设备的独特功能，将探索满足新兴的无线通信的需要。