News and Announcements

414 Ferris Hall
Wednesday, August 6, 2008 @ 9:00 A.M.
Design and Development of an APD Algorithm Development Board for Positron Emission Tomography
Rakesh Mallem, Master’s Candidate
Dr. S. K. Islam, Major Professor

Abstract
Using the PET scanner, three dimensional images of the human body with sufficient detail can be viewed which help physicians to visualize both normal metabolic functions and discover the chemical processes underlying physical abnormalities. Commercial PET scanners employ Photo Multiplier Tubes to detect the anti-matter annihilation photons and amplify the signals to a suitable level for digital sampling. Photomultiplier tubes provide extremely high sensitivity and exceptionally low noise compared to other photosensitive devices currently used to detect radiant energy in the ultraviolet, visible and near infrared regions. A combined magnetic resonance positron emission tomography (MR-PET) modality would require a solid-state photo detector due to the known gain/timing variation of PMTs with variable magnetic field. PET detector block designs have been described and implemented in the literature using APD photo detectors at moderate values of gain.

The APD Algorithm Development Board is basically a signal processing board which receives the integrated APD analog signals and outputs a digital event packet composing of position and timing data for each detected photon. These digital event packets are digitally transmitted to a downstream module for comparison with opposing detectors to detect the coincidence photons fundamental to PET. The main functions are to process analog signals from the APDs to determine if an energy qualified gamma ray event has been detected, localize the crystal position and time of the event, and transmit the event information to the control interface, en route to a coincidence processor.

DATE: Friday, July 25, 2008

TIME: 10:00am

PLACE: Claxton 202

TITLE: Hardware Sensors Monitoring with PAPI

ABSTRACT
Modern computer hardware have sensors to monitor the health and status of different computer components. Most of these sensors can be read and monitored, if you know how to do it. But, even if you can read them, you still need to know how to properly interpret (massage) the information just read. In this presentation, I will talk about the details of the work I did to enable the PAPI framework to conveniently access these sensors. I will also show results of some thermal profiling with the goal of understanding better how the computer resources are being used, and particularly, how are we using power.

COMMITTEE

• Dr. Jack Dongarra (Represented by Dr. Shirley Moore)
• Dr. Xiaorui Wang
• Dr. Yuanshun Dai (Represented by Dr. Stan Tomov)

College of Engineering
Department of Electrical Engineering and Computer Science
‐ Announcement of a Doctoral Dissertation Defense ‐
Ferris Hall 414
Tuesday, July 15, 2008 @ 9:00 A.M.
“Development of a Real-time Ultra-wideband
See Through Wall Imaging Radar System”
Yunqiang Yang, Ph.D. Candidate
Dr. Aly E. Fathy, Major Professor
Abstract
See-Through-Wall technology has emerged as a must-have enabling technology by both the military and commercial sectors. The use of Ultra-Wideband ??UWB?? in recent years has opened the doors for realizing such fascinating thoughts. The progress in UWB See-Through-Wall technology has been steady and valuable.

As a pioneer in this area, we have led the research in addressing many of the fundamental questions and resolving many of the hurdles in advancing this technology. Here we will briefly mention a few of the concerns that we have addressed: should we carry out our measurements in the frequency or time domain? What is the best operating frequency for wall penetration and obtaining a desired image resolution? In the time domain, can we develop a cost-effective approach to process very narrow pulses, not relying on the expensive solution such as real-time oscilloscope? Is it possible to develop a high-performance stand-alone system to carry out the basic STW measurements? Is it possible to utilize off-the-shelf components to realize such a system with the least design complexity? And finally, can we theoretically model such complicated problems using Advanced EM modeling?

This dissertation is to investigate these challenging areas of which the STW community has great concern, and also produce a realizable high performance STW platform system, which will aid the STW community to find the ultimate answer through experimental and theoretical work. The architectures of a realizable STW imaging system are thoroughly examined and studied in our work. We present both a conceptual system based on RF instruments and a standalone realtime system based on custom design. These developed systems utilize a reconfigurable design architecture, which allows the system to scale down/up to a desired UWB operating frequency with little difficulty. Along the way to a complete STW system, we have developed a simplified transmission line model for wall characteristic prediction; we have developed a scalable design of synthetic aperture array;we have proposed a cost-effective and efficient UWB data acquisition method for real-time STW application based on equivalent-time sampling method. The extensive measurement results reported here include wall characterization, static image formation, and tracking moveable targets behind the wall. Even though digital signal processing to generate radar images is not the major part of this research, simple methods for image formation have been implemented and results are very encouraging.

College of Engineering
Department of Electrical Engineering and Computer Science
‐ Announcement of a Doctoral Dissertation Defense ‐
Ferris Hall 414
Tuesday, July 15, 2008 @ 12:30 P.M.
“Antennas and Arrays for Mobile Platforms
– Direct Broadcast Satellite and Wireless Communication”
Songnan Yang, Ph.D. Candidate
Dr. Aly E. Fathy, Major Professor
Abstract
Flexibility of any proposed communication links is becoming one of the most challenging features. Direct broadcasting satellite services, for example, will be greatly enhanced by providing service-on-the-move. This market is very demanding as it necessitates the development of a low cost, low profile antenna that can be mounted on top of SUVs and minivans, which is capable of continuously tracking the satellite. Another example is the wireless antennas for laptops and smart-phones, where the antennas should fit within an extremely small volume and should be capable of addressing many services over wide frequency range. In this dissertation, both DBS and the wireless antennas are addressed.

In these studies, efforts have been concentrated in developing low profile planar antennas, in particular, slot arrays. Travelling wave slotted waveguide arrays have been utilized to minimize the scanning angle range limits due to their inherent beam tilt angle. CNC machines were utilized first to fabricate the early prototypes for sub-array developments. Subsequently, a low cost fabrication technology is adopted to develop a low cost and light weight full array using substrate integrated waveguides ??SIWs??. The SIW is fully characterized and an excellent equivalent model has been derived to allow easy “translation” of metallic waveguide components to SIW. Various SIW junctions, transitions, and arrays have been developed for array feed networks including a 64 radiating SIW full array and a 32 radiating SIW array with folded feed.

Meanwhile, for the wireless antennas, the utilization of reconfigurable hardware has been introduced to provide the required multi-functionality services and wide frequency coverage. Various reconfigurable antennas were developed and utilized to demonstrate their advantages compared to other design options such as wide-band or multi-band approaches. Both micro-electro-mechanical switches “MEMS” and “PIN” diodes have been successfully utilized to switch between the different configurations. The placement, control, and modeling of the switches are also discussed and novel modeling and biasing topologies are introduced. A novel, and practical concept of reconfigurable multiband antenna is introduced here too, where advantages of both the multi-band and the reconfigurable antenna structures can be simultaneously achieved while supporting more services. This newly recommended approach should have a great potential in enhancing wireless receivers next generation.