CAREER: Microwave Variable Impedance Transmission Lines

9875235 WellerThe目标描述在这个建议地址的发展和应用先进的方法来实现电路元件是微波和毫米波元件设计的基础。研究的重点是新的微波传输线架构，其电气特性可以使用静电控制的调谐元件进行操纵。通过消除对RF有源器件控制的需求，并结合微机电系统（MEMS）处理技术，这些生产线将提供更大的集成空间，并且固有地适合纳入MEMS微传感器设计。相关的教育计划介绍了现代微波传感器系统的研究，通过展示微波和其他科学的结合使用的小世界应用，用于生产可调谐传输线的方法来自于分布式线路等效于级联的电小串联电感器-并联电容器对。在计划的方法中，传输线部分将从LC对合成，每个LC对都包含微机械调谐元件。特性阻抗和传播常数是传输线的定义属性，可以使用这种新方法在宽调谐比范围内进行调整;现实的目标是实现20：1的阻抗比。调谐元件是单片的、静电驱动的微膜，其在施加的DC偏压下弯曲。这些几何形状很容易使用传统的集成电路和MEMS加工技术制造。由于集成微波和毫米波电路设计是基于分布式传输线技术，可变阻抗传输线的潜在影响是显着的。匹配网络、滤波器、衰减器和耦合器设计的新方法是这些线路的可能用途之一。它们是一种低功耗、基本上是有源（RF）器件控制的无源替代品，因此是先进相控阵天线、集成传感器/通信系统和RF模拟/数字芯片等应用的一种使能技术。研究工作将集中在确定调谐元件和控制电极的最佳几何形状，以及它们在传输线配置中的应用。有关驱动电压，传播损耗，频率带宽和相位补偿的问题将得到解决。这项工作将结合电路级和数值电磁建模使用实验表征进行。该方法将在毫米波、可变匹配网络和衰减器的设计中得到演示。该教育计划以传感器系统设计课程的开发为中心。这个高级的，基于项目的课程将使用一个真实世界的微波传感器应用的案例研究作为每学期课程的重点。个别学生或两人一组将负责设计和开发特定的子系统，例如，射频、通信和信号调理。本课程的一个重要特点是，每个传感器将与USF研究中心或当地公司合作构思，这些公司将提供相关的科学背景，协助系统架构设计，并管理传感器的实际现场部署。通过保持每个子系统的商业现成版本，并与合作者保持严格的学术联系，开发风险最小化。设计课程将追求帮助学生学习如何学习的目标，同时提供广泛的系统级工程应用。计划提供机会，向社区青年团体传授课程材料。

9875235WellerThe objectives described in this proposal address the development and application of advanced methods for realizing circuit elements which are fundamental to microwave and mm-wave component design. The research focuses on new microwave transmission line architectures whose electrical characteristics can be manipulated using electrostatically-controlled tuning elements. By eliminating the need for RF-active device control, and incorporating microelectromechanical systems (MEMS) processing techniques, these lines will offer great latitude for integration, and are inherently fit for incorporation into MEMS microsensor design. The related education plan introduces the study of modern microwave sensor systems, through foal-world applications demonstrating the combined use of microwaves and other sciences.The methodology used to produce the tunable transmission lines derives from the equivalence of distributed lines to cascaded, electrically small, series inductor-shunt capacitor (LC) pairs. In the planned approach, transmission line sections will be synthesized from LC pairs, each of which incorporates micromechanical tuning elements. The characteristic impedance and propagation constant, which are the defining properties of the transmission line, can be adjusted over wide tuning ratios using this new approach; a realistic goal is to achieve impedance ratios of 20:1. The tuning elements are monolithic, electro-statically driven micromembranes which flex under applied DC bias. These geometries are readily fabricated using conventional integrated-circuit and MEMS processing techniques.As integrated microwave and mm-wave circuit design is based on distributed transmission line technology, the potential impact of variable impedance transmission lines is significant. Fundamentally new approaches to the design of matching networks, filters, attenuators and couplers are among the possible uses of these lines. They are a Iow-power, essentially passive alternative to active (RF) device control, and thus an enabling technology for applications such as advanced phased array antennas, integrated sensor/communications systems, and RF-analog/digital chips.The research efforts will concentrate on determining optimal geometries for the tuning elements and control electrodes, and on their utilization in the transmission line configurations. Issues relating to drive voltages, propagation loss, frequency bandwidth and phase compensation will be addressed. This work will be conducted using experimental characterization in combination with circuit-level and numerical electromagnetic modeling. The approach will be demonstrated in the design of mm-wave, variable matching networks and attenuators.The education plan centers on the development of a Sensor System Design course. This senior level, project-based course will use a case study of a real-world, microwave sensor application as the focus of each semester offering. Individual students, or groups of two, will be responsible for the design and development of particular sub-systems, e.g., RF, communications and signal conditioning. A significant feature of this course is that each sensor will be conceived in collaboration with a USF research center or a local company, which will provide the relevant scientific background, assist in system architecture design, and manage the actual field-deployment of the sensor. Development risks are minimized by keeping commercial off-the-shelf versions of each sub-system on-hand, and by maintaining a strictly academic association with the collaborators. The design course will pursue the objective of helping students learn how to learn, while at the same time providing a broad exposure to system-level engineering applications. Opportunities to transfer course material to community youth groups are planned.***