Engineering Commons^™

Portable Electrochemical System For Flexible Hybrid Electronics, Anthony Joseph Hanson

Masters Theses

This work focuses on the fabrication and design of a portable electrochemical sensing system for flexible hybrid electronic (FHE) sensors. A three-electrode chemical sensor was fabricated using copper tape on polyethylene terephthalate (PET) substrate, using laser etching process. An electronic circuit was designed to measure the sensor response through electrochemical techniques to detect different concentrations of glucose. The device was calibrated to give the user a concentration value in 5 seconds. The system was also designed to preform tests such as cyclic voltammogram and chronoamperogram for various chemicals. A Bluetooth Low Energy module was used to wirelessly transmit the results …

A Comparative Study On The Stability And Degradation Of Perovskite Solar Cells, Jyotiska Chakraborty

Masters Theses

This study aims to investigate the environmental factors that affect the performance and longterm stability of the perovskite solar cells (PSCs). PSCs are based on organo-metallic halides (perovskites) that act as a light-sensitive compound that produces excitons when placed under the light. However, PSCs have a limited operating lifetime due to the degradation of the perovskite layer. There are many factors like moisture, UV light, and temperature that lead to the degradation of the perovskite layer. From the literature review, it was found that the PSCs do not degrade with the presence of oxygen in a dry and dark environment. …

Radio Direction Finding Using Pseudo-Doppler For Uav-Based Animal Tracking, Anup Karki

Masters Theses

Radio Direction Finding (RDF) is commonly used for low cost tracking and navigation systems. However, for a low cost application and mobility, the design constraints are highly limited. Pseudo Doppler (PD) can improve RDF capabilities without being cost prohibitive. This work entails the analysis of PD RDF and its potential use for Unmanned Aerial Vehicles (UAV) that are currently employed in wildlife research animal tracking. PD is based on the doppler effect or doppler shift. The doppler effect works like a frequency modulator that increases or decreases the observed frequency depending on whether a signal source is approaching or receding …

Intracellular Electrometer, Lucas M. Essenburg

Masters Theses

The Western Michigan University Neurobiology Engineering Laboratory conducts re- search in energy-efficient electrical stimulation of biological neurons. Experimental work re- quires an intracellular electrometer to inject nanoamp-level currents into a biological neuron and to measure its membrane voltage response. In order to fully understand the generation of such minute currents, an `in-house' electrometer was designed, constructed, and validated. This required exploration of various design trade-offs including precision of generated nanoamp-level currents vs. susceptibility to noise, portability vs. functionality, and cost vs. functionality. The electrometer was successfully used to stimulate and measure responses of neurons from the medicinal leech Hirudo verbana …

A Study On Controlling Power Supply Ramp-Up Time In Sram Pufs, Harshavardhan Ramanna

Masters Theses

With growing connectivity in the modern era, the risk of encrypted data stored in hardware being exposed to third-party adversaries is higher than ever. The security of encrypted data depends on the secrecy of the stored key. Conventional methods of storing keys in Non-Volatile Memory have been shown to be susceptible to physical attacks. Physically Unclonable Functions provide a unique alternative to conventional key storage. SRAM PUFs utilize inherent process variation caused during manufacturing to derive secret keys from the power-up values of SRAM memory cells.

This thesis analyzes the effect of supply ramp-up times on the reliability of SRAM …

The Umass Experimental X-Band Radar (Umaxx): An Upgrade Of The Casa Ma-1 To Support Cross-Polarization Measurements, Jezabel Vilardell Sanchez

Masters Theses

Ground-based radars are instruments commonly used to surveil the precipitation climate of the surrounding areas. Weather events are characterized by collecting backscatter data and analyzing computed products such as the Reflectivity Factor, the Doppler Velocity, the Spectrum Width, the Differential Reflectivity, the Co-polar Correlation Coefficient and the Differential Propagation Phase. The ability of the radar to transmit different polarization waves, such as horizontal and vertical polarization, allow for further analysis of the weather given the capability to perform co-polar and cross-polar measurements. The Linear Depolarization Ratio is another computed product based on the difference in power between the co-polarized and …

Emc Performance Evaluation Of Various Pcb Designs Through Simulation And Measurements, Dimitri Häring

Masters Theses

The applied research presented in this thesis is intended to deepen the understanding of various concepts related to PCB design with respect to EMC and RF performance. The first topic addressed is embedded capacitance of a PCB. The work includes decoupling capacitors and their placement relative to the IC in a combination of three different PCB stack-ups. The evaluation is performed in the frequency domain and time domain. The next topic discussed is the EMC/ EMI filters which are essential measurements to protect a device or subsystem from EMI. The circuit's load is usually unknown. A generic filter design is …

Improving Resilience Of Communication In Information Dissemination For Time-Critical Applications, Rajvardhan Somraj Deshmukh

Masters Theses

Severe weather impacts life and in this dire condition, people rely on communication, to organize relief and stay in touch with their loved ones. In such situations, cellular network infrastructure\footnote{We refer to cellular network infrastructure as infrastructure for the entirety of this document} might be affected due to power outage, link failures, etc. This urges us to look at Ad-hoc mode of communication, to offload major traffic partially or fully from the infrastructure, depending on the status of it.

We look into threefold approach, ranging from the case where the infrastructure is completely unavailable, to where it has been replaced …

To Study The Current Distributions Of An Antenna In Magnetized Collisional Plasma Via Pffdtd Simulations, Sindhuja Moravineni

Masters Theses

This thesis paper talks about the study of current distributions on dipole antenna immersed in collisional plasma. Analytical models like Balmain’s[6] one dimensional triangular current distribution, Staras[8] proposed and developed by Nikitin’s[10] threedimensional exponential current distribution and the PF-FDTD (Plasma Fluid- Finite Difference Time Domain) model[11] are compared against the Auroral Space Structure Probe (ASSP) flight data in order to show how data analysis can benefit. PF-FDTD model is used to study the antenna in weakly collisional plasma and the comparisons of the analytical and numerical solutions show that numerical model match better for data analysis of flight data sweeps …

Energy Efficiency Of Computation In All-Spin Logic: Projections And Fundamental Limits, Zongya Chen

Masters Theses

Built with nanomagnets, a spintronic device called the all-spin logic (ASL) device carries information with only spin currents, resulting in a low power supply--10 mV. This voltage is 100 times smaller than the conventional CMOS devices (usually 0.8~1V). The potential for improved energy efficiency made possible by the low operating voltage of ASL makes it one of the most promising devices among its post-CMOS competitors.

The basic working principles of ASL device are introduced in this thesis and two complementary approaches to studying energy efficiency of computation are applied to a common set of ASL circuits: (1) a circuit simulation …

Insar Simulations For Swot And Dual Frequency Processing For Topographic Measurements, Gerard Masalias Huguet

Masters Theses

In Earth remote sensing precise characterization of the backscatter coefficient is important to extract valuable information about the observed target. A system that eliminates platform motion during near-nadir airborne observations is presented in this thesis, showing an improvement on the accuracy of measurements for a Ka- band scatterometer previously developed at Microwave Remote Sensing Laboratory (MIRSL). These very same results are used to simulate the reflectivity of such targets as seen from a spaceborne radar and estimate height errors based on mission-specific geometry. Finally, data collected from a dual-frequency airborne interferometer com- prised by the Ka-band system and an S-band …

Distributed Element Designs For A Wireless System, Nicholas Anthony Dipisa

Masters Theses

A prototype binary frequency shift keying (BFSK) RF link operating in the 2.4 GHz ISM band was identified as a need for a potential undergraduate engineering laboratory activity. This system would be used to showcase various RF circuit engineering principles and techniques such as controlled trace impedances, frequency mixing, voltage-controlled oscillators, distributed element filters, and power splitters. This investigation focused on designing a prototype system that put a priority on ease of measurement and circuit tuning to help foster a more hands on approach. Each major circuit element was broken into separate PCBs to increase the modularity of the design …

Vhf Transmitter Development For Wildlife Tracking, Bryan Westra

Masters Theses

Wildlife biologists often use collars with VHF transmitters to gather wildlife data. The purpose of this project is to determine the best approach to designing a wildlife tracking VHF transmitter on a Printed Circuit Board (PCB). A variety of frequency generation methods were considered for the transmitter, including transistor-based crystal oscillators and chip based solutions from the chip manufacturers Analog Devices and Silicon Labs. Prototypes of the feasible options were built and evaluated for cost, power consumption, efficiency, size, frequency range, signal bandwidth, and frequency stability. It was found that the Silicon Labs Si4010 chip was the best solution based …

Estimating Electromagnetic Emissions From A Site Installation With Multiple Racks Of Server Equipment, Ze Sun

Masters Theses

“There are hundreds, sometimes even thousands, of servers working simultaneously inside a data center. Their radiation can be a problem and cause EMI issues. However, it is not feasible to perform full-wave simulation of these racks because of the large electric size of the model. In this thesis, an algorithm is proposed to predict the emission form rack array. The equivalent dipole source is extracted from EMI measurement data of a single rack and used as the radiation source in the multiple rack model. The coupling between racks cannot be ignored, but through the simulation, it is also found that …

Unified Probe Launch Pattern Design And Methodology Of Differential Probe Characterization, Han Deng

Masters Theses

"Differential probe is wildly used in the signal integrity area to do the accuracy signal measurement in frequency domain or time domain. Comparing with traditional SMA connector measurement, the probe measurement has several advantages such as the high flexibility and measurement efficiency. Nevertheless, the probe has some disadvantages such as multiple design patterns and the difficulty of fast landing. In this thesis, a unified probe landing pattern is provided to solve the con of probes and a probe testing fixture is designed for characterize probe and extract the probe model.

In the first portion, a unified differential probe launching pattern …

Modeling Impact Of Glass Weave On Differential Phase Skew By Design Of Experiments Method, Feng Zhang

Masters Theses

"The glass weave structure of a manufactured Printed Circuit Board (PCB) is scanned under a Scanning Electron Microscope (SEM), with top-down and cross-sectional views. Previously, analytical methods were used to investigate the glass-weave effect on transition properties in a PCB. Based on the SEM observation, this study was conducted to build full-wave models using various glass-weave types and different relative positions between differential traces and glass-weave bundles. This study aims to obtain the relationship between the glass weave and trace geometry, and the phase skew of the differential trace by using Design of Experiment (DoE) method and simulation results"--Abstract, page …

Experimental Characterization Of Common-Mode Sources For Prediction Of System Level Common-Mode Current On Cable Harnesses, Sameer Sudha Arun Walunj

Masters Theses

"Common-mode current on cable harnesses is often the primary source of radiated emissions below several hundred megahertz. It is difficult, however, to estimate common-mode currents that will occur in a system from component level tests because the common-mode impedances are different in the system. Research presents two methods for using simple component level tests to estimate equivalent common-mode source voltages and source impedances responsible for generating common-mode current. Key to these methods is assuming the harness can be represented with two transmission lines, one terminated with a short and one with an open. Equivalent sources are predicted for those circuits …

High-Speed Pcb Trace Design Using A Behavioral Surface Roughness Model And High-Speed Test Coupon Design With Non-Functional Pads, Han Gao

Masters Theses

"In high-speed digital systems as data rates increase to tens of gigabits per second, the loss from the conductor surface roughness cannot be ignored. Djordjeic and Huray roughness model is widely used to count for the conductor roughness loss. However the practical application of the existed models are not straight forward since the frequency-dependent dielectric loss is usually unknown, leading to high discrepancies at high frequencies (above 10 GHz). To solve this problem, a behavioral model was developed by adding a dispersive term to the dielectric. The dispersive term in the model captures dispersion behavior observed in the measurement accurately. …

Coupling Path Visualization Based On Reciprocity Theorem, Yang Zhong

Masters Theses

"A new method to visualize coupling path is proposed to help solve EMI problems. Based on the reciprocity theorem and the concept of reaction, coupling coefficient (CC) is defined to characterize coupling power density. For two-port networks, surface integral of CC can represent coupled voltage on the open-circuited port or coupled power on the loaded port. For dipole-moment based systems, surface integral of CC can represent coupled field components. The calculated CC should be a complex scalar at each point. By properly adjusting the excitation phases, the imaginary part of surface integral of CC will be zero and thus can …

Passively-Coded Embedded Microwave Sensors For Materials Characterization And Structural Health Monitoring (Shm), Katelyn Rose Brinker

Masters Theses

"Monitoring and maintaining civil, space, and aerospace infrastructure is an ongoing critical problem facing our nation. As new complex materials and structures, such as multilayer composites and inflatable habitats, become ubiquitous, performing inspection of their structural integrity becomes even more challenging. Thus, novel nondestructive testing (NDT) methods are needed. Chipless RFID is a relatively new technology that has the potential to address these needs. Chipless RFID tags have the advantage of being wireless and passive, meaning that they do not require a power source or an electronic chip. They can also be used in a variety of sensing applications including …

Emi Design Of Flyover Qsfp (Fqsfp) Connector For 56+ Gbps Applications, System Level Modelling Of The Z-Directed Component (Zdc), Pranay Kumar Vuppunutala

Masters Theses

"This thesis comprises of two parts. Firstly, the Flyover Quad Small Form Pluggable (FQSFP) approach for 56+ Gbps applications is introduced to overcome the limitations from a large loss on typical QSFP ports with surface mount to Printed Circuit Board (PCB) traces. By replacing the PCB traces to the twinax cables, it is possible to achieve around 7 dB lower insertion loss at 40 GHz for the 12-inch path from the switch IC to connector than that of PCB trace with a low loss substrate. Also, to investigate electromagnetic interference (EMI) aspect of FQSFP approach, a simulation model of FQSFP …

Near-Field Scanning Based Shielding Effectiveness Extraction For Board Level Shielding Cans, Harsh Shrivastav

Masters Theses

"The conventional definition of shielding effectiveness is well suited for calculating electromagnetic shielding in the far-field. However, in the near field, shielding effectiveness calculation is not so straight forward. In radio frequency interference problems, most of the field coupling occurs in near field. Having a well-defined method to calculate near-field shielding effectiveness is important for estimating the suppression of radio frequency interference using the shield cans. In this research, a method to extract the shielding effectiveness of board level shielding cans using near field scanning is developed. Shielding effectiveness is defined by modelling the shielded noise source as equivalent dipole …

Microwave Detection Of Surface Breaking Cracks In Metallic Structures Under Heavy Corrosion And Paint, John Robert Gallion

Masters Theses

"We live in the world of "aging infrastructures". In this environment, critical and heavily utilized infrastructure, i.e. ships, planes, bridges, etc., are operating at or beyond their designed age. Replacement is no longer an option and "retirement for cause" is the current approach to maintenance and replacement. Consequently, there is an ever-increasing demand for efficient and robust nondestructive evaluation (NDE) methods that can determine the physical health of these structures. Large structures, which are primarily made of metals, either steel or aluminum, are susceptible to high-stress cracking and corrosion. Stress-induced cracks in heavily corroded steel, used in bridges, railroads, storage …

Radiation Immunity In Cable Harnesses And Differential P/N Skew In Pcb, David Nozadze

Masters Theses

"We develop an efficient method to model RF immunity of multiwire cable harnesses and study differential P/N skew effects on channels, channel performance and specifically on the eye diagrams at the SerDes receiver.

External radiation can induce unwanted signals in transmission lines. For example, external radiation from an antenna induces common-mode currents on the outer surface of cable shields. This common-mode signal makes its way through the shied due to its imperfections, inducing the inner common mode. When twisted pairs inside the cable are not balanced, inner common mode is in turn converted to the differential mode, which might compromise …

Practical Methods For Source Separation In Emc Measurements, Yuanzhuo Liu

Masters Theses

"Electromagnetic emission is critical in the electronic industry with the rapid growth of the development of the electronic device. To identify the emission from the multipule sources, two methods are proposed in the near field scan and total radiated power measurement respectively.

The first method can be applied in the measurement of the field generated by multiple non-correlated sources. The contribution of each source is determined using a blind source separation (BSS) technique. The measurements are performed using one scanning probe and stationary reference probes, avoiding the need to measure the spatial correlations of the random field. The resolving result …