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.
