MRI: Acquisition of Ultra-Wide-Band Measurement and Modeling Facilities for Multidisciplinary Research

自2002年FCC批准超宽带（UWB）频谱（1.99-10.6 GHz）以来，许多UWB产品目前正在开发中，用于传感和通信。超宽带雷达在相对较低的频率下具有非常大的带宽，能够实现高分辨率和良好的穿透力。因此，UWB雷达非常适合于检测和成像被遮挡的目标，例如，墙后的人类，地下洞穴，或生物组织。 因此，它被认为是一种有前途的技术，应用范围从物理安全到生物医学成像。 UWB无线通信还具有独特的优点，特别是对于短距离城市/室内环境，因为高容量，抗多径和干扰，以及在多用户情况下的简单可扩展性。 目前关于UWB的IEEE标准的争论表明，工业界打算积极追求这个有前途的市场。 然而，UWB的物理层理解，包括散射，移动的/城市传播，和天线特性，仍然是一个新兴的领域。UWB雷达和通信技术中的关键挑战之一是如何克服由传播通过色散闭塞材料引起的信号失真、由频率相关天线辐射引起的色散、由嵌入式半导体器件引起的非线性效应以及过度简化的窄带散射和传播模型的使用。 由于缺乏这种理解，目前的UWB雷达和通信系统受到限制，无法充分发挥其潜力。 该研究小组由德克萨斯大学泛美分校的四名教师和德克萨斯大学奥斯汀分校的一名教师组成，他们确定了三个与UWB雷达和通信相关的项目，这些项目严重依赖于仪器的共同核心;特别是UWB电磁场和信号的高速时域测量。 此外，雷达成像和半导体建模中的两个相关项目需要进行高速时域测量的能力。 在UTPA，拟议的仪器包括1）由超高速数字示波器和脉冲发生器组成的时域测量系统; 2）商业电磁仿真软件; 3）直流和高功率参数半导体测试设备; 4）天线定位系统和吸收器。 UT Austin需要一台高性能矢量网络分析仪。 该仪器建立在现有设施的基础上，将大大扩展我们目前和未来项目的研究能力。 该仪器的直接应用将集中在UWB技术的三个方面：1）UWB检测和成像的闭塞目标; 2）时域特性的UWB天线与嵌入式电路; 3）UWB电磁通信和传感。 此外，该仪器将支持两个相关的研究项目：4）最大分辨率距离多普勒成像和5）非线性半导体器件表征。虽然每个PI将领导五个项目中的一个，但有很强的重叠，其中三个PI已经有研究合作的历史。 更广泛的影响UTPA是一个公共机构，位于下格兰德河山谷的南得克萨斯州。学生人口85%是西班牙裔，大多数是第一代大学生，大多数有资格获得某种形式的经济援助。该PI已雇用至少28名本科生的研究项目，并至少有14名本科生已出版的作者或共同作者。 对于这个项目，我们有一个特殊的机会，每年通过一个已经资助的国家/行业计划，支持新的电气工程专业学生在UTPA校园内的技术就业涉及八到十二名大一和大二学生。 其中三名PI是UTPA的初级教师，UTPA的电气工程硕士课程还很年轻。 通过加强我们与主要研究机构（如德州大学奥斯汀分校）教师的现有合作，我们希望改善该机构的研究记录，并为格兰德河谷的硕士生过渡到博士研究提供更多机会。 我们预计，十到二十个研究生将在未来八到十年内使用所提出的仪器进行论文研究。

Intellectual Merit Since the approval of the ultra-wide-band (UWB) frequency spectrum (1.99-10.6 GHz) by the FCC in 2002, many UWB products are currently under development for both sensing and communications. With a very large bandwidth at a relatively low frequency, UWB radar is capable of achieving both high resolution and good penetration. Therefore, UWB radar is well-suited for detecting and imaging occluded targets, e.g., humans behind walls, caves underground, or biological tissues. Consequently, it is recognized as a promising technology for applications ranging from physical security to biomedical imaging. UWB wireless communications also have unique advantages, especially for short range urban/indoor environments, because of high capacity, resistance to multipath and interference, and simple scalability in multi-user situations. The current debate over IEEE standards for UWB indicates that industry intends to aggressively pursue this promising market. However, the physical layer understanding for UWB including scattering, mobile/urban propagation, and antenna characterization, is still an emerging area. One of the key challenges in UWB radar and communications technology is how to overcome the signal distortion caused by propagation through dispersive occluding materials, dispersion due to frequency-dependent antenna radiation, nonlinear effects due to embedded semiconductor devices, and the use of oversimplified narrowband scattering and propagation models. Due to this lack of understanding, current UWB radar and communication systems are limited from reaching their full potential. The research team, a collaboration of four faculty at the University of Texas-Pan American and one at the University of Texas at Austin, have identified three projects related to UWB radar and communications that depend critically on a common core of instrumentation; in particular, high-speed time-domain measurement of UWB electromagnetic fields and signals. In addition, two related projects in radar imaging and semiconductor modeling need the ability to make high-speed time-domain measurements. At UTPA the proposed instrumentation includes 1) a time domain measurement system consisting of a very high-speed digital oscilloscope and pulse generator; 2) commercial electromagnetic simulation software; 3) DC and high-power parametric semiconductor testing equipment; 4) antenna positioning system and absorbers. At UT-Austin, a single high performance vector network analyzer is requested. The instrumentation builds upon existing facilities and will greatly extend our research capabilities for both the current and future projects. The immediate application of the instrumentation will focus on three aspects of UWB technology: 1) UWB detection and imaging of occluded targets; 2) time-domain characterization of UWB antennas with embedded circuits; 3) UWB electromagnetics for communications and sensing. In addition, the instrumentation will support two related research projects: 4) maximum resolution range-Doppler imagery and 5) nonlinear semiconductor device characterization. While each PI will lead one of the five projects; there is strong overlap, and three of the PIs already have a history of research collaboration. Broader Impacts UTPA is a public institution located in the Lower Rio Grande Valley of South Texas. The student population is 85% Hispanic, the majority are first generation college students, and most qualify for some form of financial aid. The PIs have employed at least twenty-eight undergraduate students on research projects, and at least fourteen undergraduate students have been publication authors or co-authors. For this project, we have a special opportunity to involve eight to twelve freshmen and sophomore students per year through an already funded state/industry program that supports on-campus technical employment for new electrical engineering students at UTPA. Three of the PIs are junior faculty at UTPA, and UTPA.s master.s program in electrical engineering is still young. By strengthening our existing collaborations with faculty at major research institutions, like UT-Austin, we hope to improve the institution.s research track record and broaden opportunities for Rio Grande Valley master.s students to transition to doctoral studies. We expect that ten to twenty graduate students will use the proposed instrumentation for thesis research over the next eight to ten years.