ECE Department Calendar

Aug
6
Wed
Defense: Novak
Aug 6 @ 9:00 am – 11:00 am

UNIVERSITY OF UTAH
ELECTRICAL AND COMPUTER ENGINEERING DEPARTMENT

DISSERTATION DEFENSE FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

by

Ondrej Novak
Advisor: Richard Brown

RF-Powered Mixed-Signal Microcontroller with Wireless Ultra Wideband Transmitter for Electrochemistry and Bio-Sensing

Miniature electronic microsystems have become a powerful enabling tool for advanced biomedical research. The diversity of biomedical research dictates that microsystems must be developed and customized specifically for each new application. For advanced long-term experiments on animals, a custom designed system-on-chip (SoC) is usually necessary to meet desired specifications. Custom SoCs, however, are often prohibitively expensive, preventing many new ideas from being explored.

We have developed a single-chip integrated microsystem that offers the most commonly used sensor interfaces, high computational power, and which requires minimum external components to operate. Included peripherals can also drive electrolysis or redox reactions. The SoC is highly modular and well suited for prototyping in- and ex-vivo experimental devices, eliminating the high cost of SoC development for each new application.

Additionally, the system includes a wireless ultra-wide band (UWB) transmitter. An investigation of the suitability of the UWB technology for neural recording systems is presented. Experimental data capturing the UWB signal transmission through an animal head is presented and a statistical model for large-scale signal fading is developed.

Wednesday, August 6, 2014
9:00 a.m.
Eccles Boardroom
Warnock Engineering Bldg (WEB)

The public is invited

Aug
11
Mon
Grades available
Aug 11 – Aug 13 all-day
Grades available
Aug
13
Wed
Defense-Abu Saleh Imtiaz @ Sorenson Molecular Biotechnology Building (SMBB) room 2660
Aug 13 @ 2:15 pm – 3:30 pm

Title: Piezoelectric micro-resonators on Si for inductor free embedded (on-chip) power converters in PV powered autonomous micro-systems


Abstract:
Microelectromechanical systems (MEMS) resonators on Si have the potential to replace the discrete passive components in a power converter. The main intention of this dissertation is to present a ring-shaped aluminum nitride (AlN) piezoelectric micro-resonator that can be used as an energy-transferring device to replace inductors/capacitors in low power resonant converters for biomedical applications in Autonomous Microsystems. The zero voltage switching (ZVS) condition for a series resonant converter incorporating the proposed MEMS resonator has been presented analytically and verified through experiment. This ZVS condition can be found in terms of the equivalent circuit parameters of the resonator. To the best of my knowledge, a ZVS model for thin film devices has not yet been reported in the literature. A CMOS-compatible fabrication process has been proposed and implemented. In addition, the fabricated devices have been characterized and experimental results are included. The first contour mode AlN MEMS resonator with moderately low resonant frequency and motional resistance is reported in this dissertation with measured resonant frequency and motional resistance of 87.28 MHz and 36.728 Ω respectively.
First part of this dissertation discusses the feasibility of PV powered autonomous micro-system. The reliability, efficiency and controllability of PV power systems can be increased by embedding the components of a typical power converter on the same Si substrate of a PV cell. In order to achieve more insight of the macro or surface electronics, a novel fabrication process along with experimental results have been presented in this dissertation demonstrating the integration of PV cells and major components needed to build a power converter on the same substrate/wafer. Because of the cell level power conversion, PV panels constructed from these cells are likely to be immune to partial shading and hot-spot effects. The effect of light exposure on converter switches has been analyzed to understand the converter behavior at various illumination levels. Simulation and experimental results have been provided to support this analysis. In addition to the process-related challenges and issues, this work explains the justification of this integration by achieving higher reliability, portability and complete modular construction for PV-based energy harvesting units for autonomous micro-systems.

Aug
18
Mon
Fall 2014 House Bill 60 registration
Aug 18 – Aug 20 all-day
Fall 2014 House Bill 60 registration
Aug
25
Mon
Classes begin
Aug 25 all-day
Classes begin
Graduate Seminar – “Welcome and Introduction” @ Warnock (WEB 1250)
Aug 25 @ 3:00 pm – 4:00 pm
Graduate Seminar - "Welcome and Introduction" @ Warnock (WEB 1250)

Dr. Gianluca Lazzi

University of Utah Electrical & Computer Engineering Department

When: Monday, August 25, 2014 at 3:05 p.m.
Where: Warnock 1250

During this first Graduate Seminar of Fall 2014, Dr. Lazzi will welcome students to the 2014-2015 academic year and go over the format for Graduate Seminar for the remainder of the semester.

Aug
27
Wed
Mohamed Othman Defense @ Chemical Engineering Conference Room MEB 3291
Aug 27 @ 9:00 am – 11:00 am

UNIVERSITY OF UTAH
ELECTRICAL AND COMPUTER ENGINEERING DEPARTMENT

DISSERTATION DEFENSE FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

by

Mohamed Abou Bakr Othman
Advisor: Behrouz Farhang

Detection of Nondeterministic Linear Chirps in non-Gaussian Noise Background


Chirp signals arise in many applications of digital signal processing. In this dissertation, we address the problem of detection of chirp signals that are encountered in a bistatic radar which we are developing for remote sensing of cosmic ray induced air showers. The received echoes from the air showers are characterized by their large Doppler shift (several tens of MHz), and very short sweep period (~10s). This makes our astrophysical problem a challenging one, since a very short sweep period is equivalent to a very low energy chirp signal. Furthermore, the related parameters of the received echoes are nondeterministic since they are tied to the physical parameters of the air showers that are stochastic in nature. In addition, our problem is characterized by the rarity of the expected chirp-echoes to be received, few events per week, and thus, background noise reception is the case most of the time. The primary focus of this research is to address these challenges and find an optimized detection approach under the existing receiver environment which contains non-Gaussian noise and characterized by low signal-to-noise ratio (SNR).

Matched filters are commonly used in radar systems when the chirp signal is known. In our first method, we revisit this context and use a “matched-filter” as a basis of building a rake-like receiver which consists of a set of filters matched to quantized chirp rates, logarithmically distributed within the chirp-rate interval of interest. We examine the detection capability of the proposed structure through extensive theoretical and numerical analysis. Theoretical analysis and simulation results prove that the proposed detector has high detection capability for a range of chirp slopes in a low SNR environment.

A major source of false-alarms found to be due to sudden noise spikes that cover wide frequency bands. These transient signals have high amplitudes and occur at random time instants. This leads to erroneous detection decision. We study the influence of amplitude limiting the noisy signal on reducing the received false alarms and enhancing the detection performance of the proposed rake-like receiver.

In our second method, we use Hough transform (HT), which is widely used in the area of image processing for the purpose of finding parameterized patterns, as a basis of building a robust detection technique. We examine the detection capability of the proposed structure through theoretical and numerical analysis. Our results prove that the proposed detector has high detection capability for a range of chirp slopes in a low SNR environment.

The introduced detection algorithms are implemented over a Virtex-5 FPGA. National Instruments modules are used as a high-performance custom hardware. Due to rarity of received echoes, we emulate the expected radar echoes to evaluate the system performance. The detection performance of the emulated echoes is examined using the implemented receiver at the field. Also, we compare the performance of both detectors.

 

Wednesday, August 27, 2014
9:00 a.m.
Chemical Engineering Conference Room
Merrill Engineering Building (MEB) Room 3291

The public is invited

Sep
1
Mon
Labor Day Holiday
Sep 1 all-day
Labor Day Holiday
Last day to add without a permission code
Sep 1 all-day
Last day to add without a permission code
Sep
3
Wed
First Session Classes: Last day to drop (delete) classes
Sep 3 all-day
First Session Classes: Last day to drop (delete) classes