Micromachined Standards for Calibrated Millimeter and Submillimeter-Wave Network Measurements

0501391 Barker智力优势：在微波和毫米波系统开发中发挥关键作用的测试和测量基础设施要么稀缺、昂贵和复杂，要么在太赫兹频谱区域（也称为亚毫米波区域，通常被认为是从300 GHz延伸到3 THz的频带）的大部分区域不存在。目前，为太赫兹应用设计的器件和子系统主要依赖于比例模型--在器件或子系统集成到完整的仪器中之前，通常不可能对其性能进行全面表征。六端口反射计能够使用相当简单的功率检测器电路测量精确的散射参数。这种方法的优点是，它比更复杂的矢量网络分析仪更容易扩展到太赫兹频率范围。然而，该技术需要两步校准技术。第一步涉及到使用的滑动终端，描绘出一个圆的复反射系数平面，使sixport被转换为一个等效的四端口反射计。然后使用网络分析仪校准的标准技术（例如，短开路负载）。不幸的是，在100 GHz以上，这些滑动端接不是特别坚固，这导致校准中的显著误差。因此，本计画将致力于模拟与设计校准六端口分析器的量测标准。滑动端接可利用分布于沿着短路或开路传输线上的RF-MEMS变容二极管以电子方式实现。RF-MEMS可变电容是这种应用的理想选择，因为它可以实现相对于相移的相当恒定的损耗。然而，在亚毫米波频率下，RF-MEMS梁内的寄生电容和电感将显著降低可以实现的相位变化量。因此，本计画将探讨新的方法，以增加RF-MEMS元件在次毫米波区域的可达成相位变化。 更广泛的影响：这项研究计划将加强和支持一些重要的研究，教学和推广活动在弗吉尼亚大学。此外，在该资助下开展的工作将是通过为仪器校准提供可靠和精确的MEMS标准来建立亚毫米波频谱和仪器测量基础设施的重要一步。虽然这项工作的大部分最初影响将由直接依赖毫米波和亚毫米波技术的社区感受到，但这项研究也将有利于新兴应用，如化学和生物制剂传感，缩放雷达范围系统，该计划的最重要受益者将是弗吉尼亚大学和其他相关机构的研究生和本科生在高频器件、毫米波工程和亚毫米波仪器研究方面。此外，我们在弗吉尼亚大学的研究团队与Virginia Diodes，Inc.一家专注于将太赫兹技术推向市场的小公司，以及国家射电天文台的中央发展实验室。

0501391BarkerIntellectual Merit: The test and measurement infrastructure that has played such a pivotal role in the development of microwave and millimeter-wave systems is either scarce, expensive and complex, or does not exist for much of the terahertz region of the spectrum (also known as the submillimeter region and generally regarded as the frequency band extending from 300 GHz to 3 THz). At present, the devices and subsystems being designed for terahertz applications rely primarily on scaled modeling - full characterization of their performance is generally not possible until the device or subsystem has been integrated into a completed instrument.The six-port reflectometer is capable of measuring accurate scattering parameters using fairly simple power detector circuitry. The advantage of this approach is that it is more easily scaled up into the terahertz frequency range than the more complex vector network analyzers. However this technique requires a two-step calibration technique. The first step involves the use of a sliding termination that traces out a circle in the complex reflection-coefficient plane which allows the sixport to be converted to an equivalent four-port reflectometer. This four-port is then calibrated using the standard techniques for network analyzer calibration (ex. short-open-load). Unfortunately, above 100 GHz these sliding terminations are not particularly robust which leads to significant errors in the calibration. Therefore, this project will focus on the simulation and design of measurement standards for calibrating six-port analyzers.A sliding termination can be implemented electronically using RF-MEMS varactors distributed along a short- or open-circuited transmission line. The RF-MEMS variable capacitance is ideal for this application due to the fairly constant loss versus phase shift that can be achieved. However, at submillimeter-wave frequencies the parasitic capacitance and inductance within the RF-MEMS beam will significantly reduce the amount of phase variation that can be achieved. Therefore, this project will investigate novel methods of increasing the achievable phase variation from RF-MEMS devices in the submillimeter region. Broader Impacts: This research program will enhance and support a number of important research, teaching, and outreach activities at the University of Virginia. In addition, the work to be carried out under this grant will be an important step in building a measurement infrastructure for the submillimeter spectrum and instrumentation by providing reliable and precise MEMS standards for instrument calibration. Although most of the initial impact of this work will be felt by the communities that rely directly on millimeter and submillimeter-wave technology this research will also benefit emerging applications such as chemical and biological agent sensing, scaled radar-range systems, and ultra wideband communications.The most important beneficiaries of this program will be the graduate and undergraduate students at the University of Virginia and other institutions involved in high-frequency devices, millimeter-wave engineering, and submillimeter instrumentation research. In addition, our research team at the University of Virginia has close collaborative ties with Virginia Diodes, Inc., a small company focused on bringing terahertz technology to market, as well as the National Radio Astronomy Observatory's Central Development Laboratory.