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Full-Text Articles in Engineering

Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone Dec 2021

Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone

Master's Theses

This paper proposes a method of short-range indoor localization using differential phase measurements of synchronized two-tone ultrasonic signals in an Orthogonal Frequency Multiple Access (OFDMA) scheme. This indoor positioning system (IPS) operates at an ultrasonic frequency of approximately 40kHz and synchronizes using an infrared signal. The OFDMA scheme allows for a receiver to process the signals from multiple transmitters continuously without the signals interfering with each other. The phases of the signals are measured using Goertzel Filters, allowing for low-complexity frequency content analysis. A MATLAB simulation using the proposed localization method is performed using four transmitter nodes in the corners …


Design And Characterization Of Standard Cell Library Using Finfets, Phanindra Datta Sadhu Jun 2021

Design And Characterization Of Standard Cell Library Using Finfets, Phanindra Datta Sadhu

Master's Theses

The processors and digital circuits designed today contain billions of transistors on a small piece of silicon. As devices are becoming smaller, slimmer, faster, and more efficient, the transistors also have to keep up with the demands and needs of the daily user. Unfortunately, the CMOS technology has reached its limit and cannot be used to scale down due to the transistor's breakdown caused by short channel effects. An alternative solution to this is the FinFET transistor technology, where the gate of the transistor is a three dimensional fin that surrounds the transistor and prevents the breakdown caused by scaling …


First Order Self-Oscillating Class-D Circuit With Triangular Wave Injection, Matthew J. Carroll Jun 2021

First Order Self-Oscillating Class-D Circuit With Triangular Wave Injection, Matthew J. Carroll

Master's Theses

An investigation into performance improvements to the modulator stage of a class-D amplifier is conducted in this thesis. Two of the standard topologies, namely class-D open-loop pulse-width modulation (PWM), and the improved self-oscillating feedback system are benchmarked against a topology which includes both a hysteretic comparator in a feedback loop and triangle wave injection. Circuit performance is analyzed by comparing how the triangle injection circuit handles known issues with open-loop and self-oscillating circuits. Using this analysis, it is shown that the triangle injection topology offers an improved power supply rejection ratio relative to open-loop PWM and reduces distortion generated by …


Scalable Cognitive Radio Network Testbed In Real Time, Kevin Z. Yu Jun 2021

Scalable Cognitive Radio Network Testbed In Real Time, Kevin Z. Yu

Master's Theses

Modern society places an increasingly high demand on data transmission. Much of that data transmission takes place through communication over the frequency spectrum. The channels on the spectrum are limited resources. Researchers realize that at certain times of day some channels are overloaded, while others are not being fully utilized. A spectrum management system may be beneficial to remedy this efficiency issue. One of the proposed systems, Cognitive Radio Network (CRN), has progressed over the years thanks to studies on a wide range of subjects, including geolocation, data throughput rate, and channel handoff selection algorithm, which provide fundamental support for …


Zero Voltage Switching Hybrid Voltage Divider Converter, Timothy Jeong Jun 2021

Zero Voltage Switching Hybrid Voltage Divider Converter, Timothy Jeong

Master's Theses

This project proposes a new hybrid voltage divider DC-DC converter that utilizes switching capacitors and inductors to produce zero voltage switching (ZVS) at the turn on state of its switches. By achieving ZVS, the switching losses are significantly reduced; thus, increasing the overall efficiency of the converter at various loads. The goal for this thesis is to perform analysis of the operation of the converter, derive equations for sizing the main components, and demonstrate its functionality through computer simulation and hardware prototype. Results of the simulation and hardware testing show that the proposed converter produces the desired output voltage while …


Design And Modeling Of A Distributed Network For The Dc House Project, Lauren N. Rotsios Jun 2021

Design And Modeling Of A Distributed Network For The Dc House Project, Lauren N. Rotsios

Master's Theses

This thesis covers the design and simulation of a model for a distributed network of DC Houses in MATLAB Simulink. The model will allow for sharing of power between houses within the network. The developed model consists of five separate DC House branches with local power generation. Each branch consists of a PV MPPT charge controller subsystem, a resistive load, and a bidirectional buck-boost converter subsystem. The high voltage side of every bidirectional buck-boost converter is connected together through the transmission line at a single high voltage DC bus. The performance of the individual components of the model is verified …


Development Of A Portable Low-Moisture Food Pasteurization Device Using Rf Heating, Eric Jason Ohata Jun 2021

Development Of A Portable Low-Moisture Food Pasteurization Device Using Rf Heating, Eric Jason Ohata

Master's Theses

Bacterial presence in low-moisture foods such as flour, cereals, baby formula, and spices, have become a concern due to sanitizing challenges. The food industry currently focuses on wet food sanitation as opposed to low-moisture foods because of bacteria’s inability to reproduce in low water activity media. Traditionally, food processing RF heating pasteurizes in mass quantities while an equivalent consumer device does not exist the market today. A consumer product would help eliminate food waste by providing an easy way to sanitize food and extend shelf life. The Portable Food Pasteurization (PFP) project is an interdisciplinary project involving the Electrical Engineering, …


Design Of An Ultra-Wideband Frequency-Modulated Continuous Wave Short Range Radar System For Extending Independent Living, Toai-Chi Nguyen Apr 2021

Design Of An Ultra-Wideband Frequency-Modulated Continuous Wave Short Range Radar System For Extending Independent Living, Toai-Chi Nguyen

Master's Theses

Falls in the disabled and elderly people have been a cause of concern as they can be immobilized by the fall and have no way to contact others and seek assistance. The proposed frequency modulated continuous wave (FMCW) short range radar (SRR) system, which uses ultra-wideband (UWB) signals can provide immediate assistance by monitoring and detecting fall events. The unique characteristics of this system allow for a frequency-based modulation system to carry out triangulation and sense the location of the fall through the usage of a continuous chirp signal that linearly sweeps frequency. This project focuses on the development, design …


Controller Modeling And Stability Analysis Of Multiple Input Single Output Dc-Dc Converter, Astha Adhikari Mar 2021

Controller Modeling And Stability Analysis Of Multiple Input Single Output Dc-Dc Converter, Astha Adhikari

Master's Theses

This thesis entails the stability analysis of the Multiple Input Single Output (MISO) DC-DC converter developed for the DC House Project at Cal Poly. A frequency domain control system model of the MISO converter was designed and constructed using MATLAB Simulink. Transfer functions were derived and modeled for each stage of the converter to best fit the converter circuit system used in the original MISO circuit. Stability metrics such as overshoot, undershoot, rise time, phase margin and gain margin were measured to evaluate and analyze the stability of the converter. These metrics were measured with the original model including the …


Early Wildfire Detection With Line Sensors, Virginia Yan Mar 2021

Early Wildfire Detection With Line Sensors, Virginia Yan

Master's Theses

Over the last few years, wildfires have become more devastating to communities as the fires are inevitably destructive to many homes, businesses, and ecosystems. Frequent wildfires also pose a significant threat to power grids and nearby residents as they can damage transmission lines and other electrical equipment, which in turn can cause major power shutdowns. Especially in western U.S., severe drought conditions and weather variability cause residents to become more vulnerable to wildfire disasters as their safety is threatened. We are incompetent to control the wildfires effectively despite existing advanced technologies. Hence, an algorithm based on energy conservation and heat …