Electrical and Electronics Commons^™

Reconfigurable Metasurface For 5g & Beyond Wireless Communication, Monisha S

Theses and Dissertations

The potential new applications and increasing demands of future 5th generation (5G) and beyond wireless communication indicate a promising future for mobile communications. However, the transmission medium has traditionally been seen as an unpredictable factor between the sender and receiver. As we enter the digital era of wireless communications, signal quality is deteriorating due to environmental interferences.

With the continuous advancement of technology, there is an increasing need for advanced solutions that can handle complex applications such as haptic communications, the Internet of Things for smart cities, automation, and manufacturing. One technology that has received much attention is the reconfigurable …

Parallel Communications In Single-Core Optical Fibers Utilizing Spatial Domain Multiplexing And Wavelength Division Multiplexing, Mingxuan Tu

Theses and Dissertations

This endeavor proposes a hybrid parallel optical communication architecture in single-core fibers combining WDM in O-band (1270 nm, 1310 nm, 1310 nm, and 1330 nm) and two-channel SDM. The proposed architecture applies carefully designed delays in each propagating channel to achieve synchronization and, therefore, realizes parallel transmission in single-core fibers without the help of Serializer/De-serializers (SerDes). A mathematical model of SDM, calculations on delays between each optical channel, simulation of the hybrid architecture, experimental setup, and the testing and analysis of channel performance have been provided. A design of a photonic integrated circuit based on thin film lithium niobate electro-optic …

Increasing Optical Channel Capacity By Integrating Pam4 Modulation With Wavelength Division Multiplexing And Spatial Domain Multiplexing, Swaroopini Harish

Theses and Dissertations

Spatial division multiplexing (SDM) is a technique used in telecommunications and networking to increase data transmission capacity over optical fiber communication channels. This multiplexing technique spatially reuses optical frequencies by allocating different spatial locations for inputs based on their inject angles. The signals travel in a helical pattern within the carrier fiber and exit as concentric rings. SDM enables more efficient utilization of available bandwidth and improved communication performance. In four-level pulse amplitude modulation (PAM4), each symbol represents a combination of four possible signal levels instead of the two levels in binary modulation. The four levels are denoted in different …

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Technologies For Wearable Seizure Detection: A Systematic Review, Rhema Losli

University Honors Theses

Knowing when a seizure occurred is helpful because this information can be used to evaluate the effectiveness of seizure interventions and possibly alert caregivers to emergency situations. The current practice for recording seizures outside of a hospital and without sensors is through keeping a self-reported seizure diary. This practice may be unreliable if the diary is not updated or the person having the seizure does not realize it is happening. Wearable seizure detectors aim to solve this problem by reliably recording when a seizure happened and either sending out an alert or storing the data for later analysis. In this …

Physical Effects On The Worst-Case Delay Analysis And Signal Integrity Of Buses And Spirals, Mahmoud Mahany

Theses and Dissertations

Physical effects have a significant impact on the IC design which will be investigated in this thesis. Moving toward advanced technology nodes, magnetic effects become more dominant than capacitive effects. As the dimensions of the devices go down and the interconnect manipulates the circuit behavior more and more. Cross talking and voltage drops are affecting the design heavily, however - going to the full electromagnetic point of view - current return path (CRP) adds significant parasitics to the performance of the chip. Neglecting the CRP gives wrong intuition and simulation of the designs, especially that the environment and surroundings can …

Remote Vibration Based Monitoring Of Bridge Scour, Alan Kazemian

Dissertations

The gradual erosion of the sediment around a bridge foundation is called Scour. This erosion is caused by water flow and increases during times of high-water flow such as flooding. The scour leaves the bridges structurally unsound over time and jeopardizes the safety of the structure. Approximately 60 percent of bridge failures in the United States are caused by scour. A variety of types of devices have been used to detect scour. Most of these devices only observe the scour and not the structural integrity of the bridge. The typical approach has relied on visual inspections of the bridges after …

Mechanical And Electrical Characterization Of Conductive Polymer-Derived Ceramic Composite, Jace R. Henry

ENGS 88 Honors Thesis (AB Students)

Polymer-derived ceramics (PDCs) have found a wide range of uses typically being in high temperature or corrosive environments. Some of the current applications are in aerospace, energy storage and microelectromechanical devices. One growing interest is in additively manufacturing PDCs, as they can be printed in the polymer state, then heat treated to form a ceramic. This allows for complex, or small geometries, to be manufactured and aids in decreasing the complexity of the manufacturing process compared to traditional sintering techniques. However, one limitation of PDCs is the large shrinkage of the material and or the increased porosity due to volatile …

An Analysis Of Indoor Air Quality At Cal Poly For Sensor Design, Isabella M. Santi

Master's Theses

Prior research has shown that indoor air quality (IAQ) impacts cognitive performance. At Cal Poly, many older buildings are unable to maintain appropriate IAQ because of their outdated ventilation systems and the increasing number of students in the rooms. This work analyzes the IAQ of different buildings at Cal Poly, with a focus on Building 20. Carbon dioxide, temperature, and relative humidity inside classrooms are collected using an integrated circuit sensor and a microcontroller. A total of 38 hours of data was collected, with 22 of those hours in Building 20 specifically. We find that unlike temperature and relative humidity, …

A Hybrid Computer To Solve The Selective Harmonic Minimization Problem In Single-Phase Inverters, Dillon Nguyen

Master's Theses

Power electronics possess forms of non-ideality due to the nonlinearity present in physical switches. These switches are driven with pulse width modulation (PWM), which properly down-converts or up-converts based on converter topology. When these switches turn on or off, they introduce the main proponent of efficiency loss: harmonics. This becomes a nonlinear optimization problem with many converters. The solution proposed in this thesis is an analog/digital hybrid computer that utilizes the speed of analog computation and the accuracy of digital computing together. A Plexim RT Box provides the programmability needed for algorithms, while the analog circuit provides low-power, high-speed computation …

Smart Cushion Device For Elderly Aging In Place, Anna Dion, Nate Colley, Leonardo Bravo

Biomedical Engineering

Our task at hand is to develop a consumer-focused solution for improving elder care to provide additional peace of mind for seniors and caregivers using technology to extend independent living. We intend to create a device that will improve the quality of life of elderly individuals living alone by encouraging periodical movement throughout the day, along with monitoring pressure distribution and alerting when pressure concentration is potentially harmful. It will also alert users to the presence of moisture which can arise from spills or incontinence. The key stakeholders of this project include elderly adults over the age of 65 who …

Motor Controller Board For Cubesat Reaction Wheels, Tanner Ehlers

Electrical Engineering

Reaction wheels are crucial for CubeSats, providing precise attitude control and stability in the environment of space, enabling successful mission execution. The ‘Reaction Wheels’ project in the Cal Poly CubeSat Lab is in need of a new motor controller board due to the current board’s malfunction and inefficiencies in terms of size, complexity, power usage, and cost. Previously, other students have completed work on the mechanical design of the system, but little work has been done for the electrical components. The goal of this project is to design and test a new motor controller board that is compact, lightweight, power …

Hatt-Flow: Hierarchical Attention-Flow Mechanism For Group-Activity Scene Graph Generation In Videos, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Thi Hoang Ngan Le, Page Daniel Dobbs, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Group-activity scene graph (GASG) generation is a challenging task in computer vision, aiming to anticipate and describe relationships between subjects and objects in video sequences. Traditional video scene graph generation (VidSGG) methods focus on retrospective analysis, limiting their predictive capabilities. To enrich the scene-understanding capabilities, we introduced a GASG dataset extending the JRDB dataset with nuanced annotations involving appearance, interaction, position, relationship, and situation attributes. This work also introduces an innovative approach, a Hierarchical Attention–Flow (HAtt-Flow) mechanism, rooted in flow network theory to enhance GASG performance. Flow–attention incorporates flow conservation principles, fostering competition …

Echoes Of Nature: Using Biodata Sonification To Model Electrical Communication In Plants, Penelope Anna Alioshin

Electrical Engineering

The use of biodata sonification as a tool to visualize biological data is a response to recent developments in the intersection of art and technology. This project explores the intersection by converting the electrical impulses given off by plants into audio signals. By processing and amplifying the voltage difference between two electrodes on a plant, its communication is quantified. The goal is to use this communication model as a tool to increase ecological awareness as well as improve machine learning models. A deeper understanding of non-human communication systems, specifically those that employ superposition decision matrices, could help to drastically increase …

Design Of High Efficiency Doherty Power Amplifier, Kobi G. Kelly, Severin Pindell

Electrical Engineering

The project includes design and fabrication of a high efficiency power amplifier for a student design competition held at International Microwave Symposium (IMS) 2023. Efficient power amplifiers are critical for base station communication requiring efficient use of available power. The final design optimizes power added efficiency (PAE) and linearity. The amplifier will operate at 2.45 GHz. Competitive PAE above 50%, and C/I above 30 dB is achieved by leveraging a Doherty class amplifier using accurate discrete CGH4006P transistor models to simulate an efficient and linear design. Unique design features include optimal transistor bias point selection and power split ratios between …

Formula Sae Vehicle Dynamics Controller, Luke Edward Bosworth

Electrical Engineering

Throughout the history of motorsports, engineers have continuously pushed the boundaries of speed and control in the pursuit of enhancing vehicle performance on the track. Today’s top performing motor-vehicles leverage electric motors to the deliver instantaneous torque to the vehicle’s tires. While these electric motors can deliver a lot of power very efficiently, the delivery must be well controlled to get the most performance out of the tires. The Formula SAE Vehicle Dynamics Controller (VDC) senior project integrates vehicle modeling, state estimation, and yaw moment controls into a small- scale Formula-one style electric vehicle, improving vehicle performance and laying the …

2024 Marine Energy Collegiate Competition, Nora Riedinger, Miles Mikkelsen, Brendan Stratford, Derek Tom, Zach Kwast, Harmon Yanikian-Sutton, Kennedy Urcelay, Tori Thomas, Brady Caron

Mechanical Engineering

PolyWave Energy is the second team from California Polytechnic University at San Luis Obispo to compete in the Marine Energy Collegiate Competition. PolyWave Energy consists of Mechanical Engineering, Electrical Engineering, and Business Administration students who have worked together from September 2023 to May 2024 on designing, building, and testing a marine power device to serve a selected market.

In response to the escalating concerns surrounding carbon emissions, climate change, and the depletion of fossil fuels, California Polytechnic State University’s Polywave Energy team has developed a sustainable and reliable energy source for Autonomous Underwater Vehicle (AUV) charging. Through extensive research of …

2-Channel Eeg Neurofeedback System, Tim Erwin, Donna Nikjou, Sebastian Turkewitz

Electrical Engineering

This work describes the design of an EEG-based neurofeedback system which provides users with real-time feedback on their level of focus or relaxation. By analyzing the spectral content of the brain activity measured via scalp electrodes, focus and relaxation levels can be quantified. Based on these measurements, live feedback in the form of moving bar graphs is provided to users, allowing them to gain awareness of their mental-state and more efficiently learn how to consciously relax or focus. This project covers the design of the system, including amplification and filtering stages, digitization, and signal processing. The system interfaces with a …

Light Based Wireless Communication, Nick Ghaffarian, Gibson Puckett

Electrical Engineering

The demand for high-speed, secure wireless communication is escalating, particularly in high-density environments like urban areas, and critical sectors such as healthcare and defense. Traditional Wi-Fi struggles with issues like signal congestion, electromagnetic interference, and security vulnerabilities, compromising connectivity quality. LiFi is much more suitable for areas like hospitals which contain equipment highly sensitive to electromagnetic interference, has a high bandwidth far away from standard radio waves which enables strong communication in highly congested areas.

We developed a small scale, low-cost LiFi system to demonstrate a proof of concept of LiFi that grants the user full access to the internet. …

Cal Poly Gen 2 Battlebot Electrical System, Kelvin C. Villago

Electrical Engineering

BattleBots is a popular robot combat sport where engineers from all over the world design and construct a robot with the aim to disable or impair the opposing robot. The Cal Poly Gen 2 BattleBot aims to complete a robot from scratch with hopes to compete in the official competition. This report focuses on the electronic design behind the robot, specifically the printed circuit board (PCB) and component selection. The design process of this project involved choosing specific motors and microcontrollers based on cost, efficiency, and benefits with the end goal of a complete printed circuit board (PCB). Brushed motors …