Engineering Commons^™

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 …

Sky Survey Radio Telescope, Jack E. Mcguigan

Electrical Engineering

This document outlines the design of a radio telescope designed to perform hydrogen line sky surveys. The telescope produces radio images mapping the intensity and relative velocities of hydrogen concentrations to their sky coordinates. Over the course of a day, the telescope images the regions of space visible to it, allowing sky survey imagery to be updated daily. Sky survey images are comprised of an array of pixels corresponding to specific sky coordinates. Each 8-bit RGB pixel contains information on the concentrations of hydrogen in the brightness and relative velocity in the color. Radio images mapping the concentrations and velocities …

Design, Modeling, And Testing Of A Novel Inductor For Electric Vehicles: Iron Nitride Soft Magnetic Composites, Sydney F. Fultz-Waters, Jacob Krynock

Materials Engineering

New technology for electric vehicles (EVs) must meet the requirements of higher energy usage, lower costs, and more sustainable source materials. One promising material for EV power system components is iron nitride (IN) soft magnetic composites (SMCs) because of their competitive magnetic properties and high abundance of the source materials. As part of an ongoing program at Sandia National Laboratories, this project focused on using computer modeling to optimize the prototyping process for an iron nitride SMC toroidal inductor to reach a target inductance of 600 μH. Four inductors with different combinations of wiring (26 AWG and 20 AWG) and …

Photophoretic Optical Trapping, Essa Ababseh

Electrical Engineering

Photophoretic Optical Trapping (POT) is a relatively new concept in the field of optics which has potential application in 3D display. The POT is realized by confining a particle within a very small location of the optical system, mostly around the focus. The particle, if captured by the beam, has the potential to print visible 3D images in free space. Our POT system is encapsulated by an acrylic enclosure, which also incorporates a biconvex lens as well as an adjustable focus laser module. Particles are released around the top of the lens’ focal point until the captured particle can be …

Wireless Energy Harvesting System, Matthew Palma, Audrey Toop, Andrew Fahey

Electrical Engineering

The modern world is built upon wireless transmission of data. The signals that carry this data travel through the air, an untapped source of power. Unreceived transmissions are dissipated into useless forms of energy when they should be reclaimed. Wireless electronics can theoretically be powered by harvesting energy from the electromagnetic signals in the wireless internet frequency band. The aim of this project is to develop a system to capture ambient energy, convert it into DC power, and store the power for later use. The product will consist of three subsystems: an antenna receiver, a rectifier and voltage-multiplier, and a …

Design Of Class F-Based Doherty Power Amplifier For S-Band Applications, Kyle Chang

Master's Theses

Modern RF and millimeter-wave communication links call for high-efficiency front end systems with high output power and high linearity to meet minimum transmission requirements. Advanced modulation techniques, such as orthogonal frequency-division multiplexing (OFDM) require a large power amplifier (PA) dynamic range due to the high peak-to-average power ratio (PAPR). This thesis provides the analysis, design, and experimental verification of a high-efficiency, high-linearity S-band Doherty power amplifier (DPA) based on the Class F PA. Traditional Class F PAs use harmonically tuned output matching networks to obtain up to 88.4% power-added efficiency (PAE) theoretically, however the amplifier experiences poor linearity performance due …

Design And Analysis Of A Discrete, Pcb-Level Low-Power, Microwave Cross-Coupled Differential Lc Voltage-Controlled Oscillator, Pavin Singh Virdee

Master's Theses

Radio Frequency (RF) and Microwave devices are typically implemented in Integrated Circuit (IC) form to minimize parasitics, increase precision and tolerances, and minimize size. Although IC fabrication for students and independent engineers is cost-prohibitive, an abundance of low-cost, easily accessible printed circuit board (PCB) and electronic component manufacturers allows affordable PCB fabrication.

While nearly all microwave voltage-controlled oscillator (VCO) designs are IC-based, this study presents a discrete PCB-level cross-coupled, differential LC VCO to demonstrate this more affordable and accessible approach. This thesis presents a 65 mW, discrete component VCO PCB with industry-comparable RF performance. A phase noise of -103.7 dBc/Hz …

Maximum Trapping Focal Length In Photophoretic Trap For 3d Imaging Systems, Jason M. Childers

Electrical Engineering

This product is a photophoretic trapping system which allows varying focal lengths to test which focal lengths are possible for trapping toner particles. This system establishes that there exists a maximum trapping distance limitation and is the first time the effect of focal length is studied in a photophoretic trapping system. Increasing photophoretic trapping focal length is necessary for improving this technology as a 3D display. The 3D imaging technology is realized by dragging a microscopic (micrometer-scale) particles with a laser beam to trace an image. This technology can display fully colored and high-resolution 3D images visible from almost any …

X-Band Rf Transmitter Design For Multi-Purpose Small Satellite Communication Operations, Omer F. Gumus

Master's Theses

This thesis provides a description of the analysis, design, and tests of an X-band RF Transmitter communication system for small satellites. X-band transmitter systems are becoming popular in the upcoming deep space missions. Most of the deep-space ground stations have been using X-band frequencies to receive or transmit signals. The X-band (<10 GHz) can offer lower atmospheric losses and up to a couple of Mbps data rates for multiple satellite operations. Nowadays, many small satellites have been using frequency bands such as VHF, UHF, L, and S-band frequencies for communication. From deep space to the ground station, the low-frequency ranges are inadequate in providing Mbps level data rates and enough bandwidth for deep space missions.

The main focus of this thesis was the development of the subsystems such as gain block amplifier, Mixer, Bandpass Filter, and RF power amplifier. The subsystems were designed separately, then they were connected together to perform an end-to-end system test. One of the thesis aims is to design …

Ultra-High-Energy Neutrino Detection Antenna Simulations, Nicholas C. Garcia

Electrical Engineering

Neutrinos allow researchers to investigate high-energy galactic phenomena, such as supernovae and black holes. Neutrinos interact with their surroundings via the weak nuclear force and therefore, travel unattenuated through space and are not deflected by electromagnetic fields. However, they do rarely interact with other particles. When neutrinos interact with nucleons (protons or neutrons) in a dielectric medium (i.e.: ice sheets), they are detectable through a cone of coherent electromagnetic radiation (Askaryan Radiation) created by the particle shower generated from the neutrino interaction [1]. The Radio Neutrino Observatory in Greenland (RNO-G) detects UHE neutrinos greater than 100 PeV (10¹⁵ eV) …

Led-Based Solar Simulator, Jonathan E. Honrada

Electrical Engineering

Solar simulators are great laboratory tools that help users conduct tests with solar cells indoors. Conventional solar simulators typically use xenon arc bulbs as a light source, which can have considerable disadvantages. Recent projects have sought to design and implement LED-based solar simulators, as they are more power-efficient, inexpensive, and durable.

Based on these advantages, the goal of this project is to create an LED-based solar simulator that can replicate the characteristics of solar light, but also be tunable with controls. This broadens the testing capabilities of the device, allowing users to conduct tests with more narrow spectrums of light …

Simulation Of An Sp8t 18 Ghz Rf Switch Using Smt Pin Diodes, Andre De Souza Vigano

Master's Theses

Radio frequency (RF) and microwave switches are widely used in several different applications including radar, measurement systems, telecommunications, and other areas. An RF switch can control a radar’s transmit vs. receive mode, select the operating band, or direct an RF signal to different paths. In this study, a single pole eight throw (SP8T) switch using only Surface Mount (SMT) components is designed and simulated in Keysight’s Advanced Design System (ADS). Single pole eight throw is defined as one input and eight possible outputs. A star network configuration with series-shunt PIN diode switches is used to create the 8-way RF switch. …

Neutrino Detection Antenna, Samuel D. Keechler

Electrical Engineering

Neutrinos carry valuable information about deep space events that researchers can utilize to study the early universe. Since the first neutrino was detected in 1956, it is a relatively new physics research topic. A new state-of-the-art research facility, the Radio Neutrino Observatory in Greenland (RNO-G), was developed to detect Ultra-High Energy (UHE) neutrinos, ones with energy greater than 100 PeV (1015 electronvolts). For reference, this amount of energy lifts an apple 5 cm, or drives a neutrino, a particle 1034 times smaller by mass, near the speed of light [1]. UHE neutrino events typically occur less than five times a …

The Characterization Of Effective Electromagnetic Fields On The Safety And Quality Of Low-Moisture Foods (Effs) - Prototype Device Development, Joe G. Sandoval

Electrical Engineering

Contamination of low-moisture foods including flour, wheat grain, baby formula, and more, have increasingly become a concern due to sanitizing challenges. While industrial food processors have long used RF heating to sanitize mass quantities, an equivalent consumer device is absent from the market today. The Characterization of Effective Electromagnetic Fields on the Safety and Quality of Low-Moisture Foods (EEFS) project is an interdisciplinary effort to develop an RF heating consumer device to sanitize low-moisture foods.

A prototype device was designed to sanitize low-moisture food items using RF heating acceptable for commercial or consumer applications.

High Efficiency Rf Amplifier Design, Evan W. Johnson

Electrical Engineering

High efficiency RF power amplifiers are key to the operation of modern wireless systems. From reducing power consumption at base stations to increasing battery life in handsets, high efficiency amplifiers help system designers to meet key performance criteria for their customers. The advent of the Internet of Things and 5G will lead to mass proliferation of battery operated wireless devices, increasing demand for high efficiency systems. In this project, a high efficiency 4W narrowband PA operating at 1GHz is designed, built and tested for the IMS2020 high efficiency power amplifier (HEPA) design competition. Emphasis is placed on achieving maximum power-added …

Performance Enhancement And Characterization Of An Electromagnetic Railgun, Paul M. Gilles

Master's Theses

Collision with orbital debris poses a serious threat to spacecraft and astronauts. Hypervelocity impacts resulting from collisions mean that objects with a mass less than 1g can cause mission-ending damage to spacecraft. A means of shielding spacecraft against collisions is necessary. A means of testing candidate shielding methods for their efficacy in mitigating hypervelocity impacts is therefore also necessary. Cal Poly’s Electromagnetic Railgun was designed with the goal of creating a laboratory system capable of simulating hypervelocity (≥ 3 km/s) impacts. Due to several factors, the system was not previously capable of high-velocity (≥ 1 km/s) tests. A deficient projectile …

Dc-Dc Converter For Electric Vehicle, Jason Y. Zhou, Nicholas James Mah

Electrical Engineering

In this work, a DC-DC converter is designed for an electric vehicle. The DC-DC converter is designed to provide 500W with a 200-400V input and a 12-15V adjustable output. Electric vehicle sales are beginning to increase in popularity and the need for DC-DC converters to siphon power from the tractive system is not yet fully satisfied, especially for single-seater class vehicles. Additionally, improving performance in efficiency without sacrificing wide input voltage range can benefit future DC-DC converter designs. In the end, a forward active clamp DC-DC converter is designed and tested. Additionally, spreadsheet calculators, LTSpice simulations, and Matlab scripts were …

Designing A Simulator For An Electrically-Pumped Organic Laser Diode, Robert Hulbert

Master's Theses

Organic semiconductors provide an alternative set of basis materials to fabricate electronic devices like PN Junctions, LEDs, and FETs. These materials have several benefits over traditional inorganic semiconductors including their mechanical flexibility, reliance on renewable resources, and inexpensive large-scale manufacturability. Despite the contemporary device implementations with organic semiconductors, a solid-state electrically-pumped organic laser diode does not exist. However, organically-based lasers do exist by utilizing the organic material strictly for optical gain. The challenge occurs when charge carriers appear in the organic material. The charge carriers must reach a concentration such that population inversion occurs producing optical gain. However, between the …

Experimental Optical Pulse Picker For Lawrence Livermore National Lab, Alexander Thomas Wargo

Master's Theses

Proprietary.

Brushless Direct Current Motor Control For Inspired Flight, Aidan James Mccoy

Computer Science and Software Engineering

Brushless direct current motors have become a very common part of many modern electronics. Although they are more expensive and less robust than conventional brushed direct current motors, they provide large advantages in control, power output, longevity as well as efficiency. To make these motors run, they need more than just power. Each motor needs a separate motor controller that is responsible for taking in a signal for what speed/torque to run the motor at, and then managing the current flow to the motor to keep it spinning while fitting within these boundaries. Brushless direct current motors have a set …

The Design, Building, And Testing Of A Constant On Discreet Jammer For The Ieee 802.15.4/Zigbee Wireless Communication Protocol, Alexandre J. Marette

Master's Theses

As wireless protocols become easier to implement, more products come with wireless connectivity. This latest push for wireless connectivity has left a gap in the development of the security and the reliability of some protocols. These wireless protocols can be used in the growing field of IoT where wireless sensors are used to share information throughout a network. IoT is being implemented in homes, agriculture, manufactory, and in the medical field. Disrupting a wireless device from proper communication could potentially result in production loss, security issues, and bodily harm. The 802.15.4/ZigBee protocol is used in low power, low data rate, …

Adaptation Of Vt-Dbr Lasers For Lidar, Luke Horowitz

Master's Theses

Vernier Tuned Distributed Bragg Reflector (VT-DBR) lasers have had great success in the field of Swept-Source Optical Coherence Tomography (SS-OCT) due to their continuous and nearly 40 nm wavelength tuning range in a single longitudinal mode. Fast sweeps allow for real time imaging with micrometer resolution at a distance of a few centimeters. While this laser has proven quite useful as a medical imaging tool via OCT, it has yet to similarly prove itself for general light detection and ranging (LIDAR) applications due to range limitations that arise from a finite laser coherence length. The goal of this thesis is …

Two Senior Projects: 2.4 Ghz, 40% Efficiency Radio Frequency Amplifier, Ieee Design Contest, & Design And Implementation Of A Software Costas Loop For Audio Frequencies, Robert J. Tong

Electrical Engineering

How to Read this Document:

This document combines two senior project reports. The first senior project documents designing a class AB RF amplifier. The second, discusses the design and implementation of a software Costas loop for audio frequencies. The first report begins on the next page, while the Costas loop report starts on page 24. The two reports are orthogonal from one another. It is not a prerequisite to read the RF amplifier report before reading the Costas loop report. This document is merely two reports combined into one document. The second report, about the Costas loop, was written as …

Microwave Interferometry Diagnostic Applications For Measurements Of Explosives, Loren A. Kline

Master's Theses

Microwave interferometry (MI) is a Doppler based diagnostic tool used to measure the detonation velocity of explosives, which has applications to explosive safety. The geometry used in existing MI experiments is cylindrical explosives pellets layered in a cylindrical case. It is of interest to Lawrence Livermore National Labs to measure additional geometries that may be overmoded, meaning that the geometries propagate higher-order transverse electromagnetic waves. The goal of my project is to measure and analyze the input reflection from a novel structure and to find a good frequency to use in an experiment using this structure. Two methods of determining …

Magnetic Bearing For Bently Nevada Rk4 Rotor Kits, Sean Fowler, Garrett Olson

Mechanical Engineering

Active Magnetic Bearings (AMB) are contact free bearings that support loads by magnetic levitation. This is accomplished by generating magnetic forces with electric current through a series of electromagnets surrounding a suspended rotor mass. Along with a set of electromagnets, an AMB assembly also consists of power amplifiers for each electromagnet, a controller, and proximity sensors. The proximity sensors provide rotor position feedback to the control system, which modulates power to the amplifiers [4]. Magnetic bearings are used in several industrial applications today, including but not limited to compressors, turbines, pumps, motors, and generators. Advantages of their utility include very …

Hall Effect Modeling In Fem Simulators And Comparison To Experimental Results In Silicon And Printed Sensors, Leonardo A. Frem

Master's Theses

Finite element method simulation models for thin-film semiconductor-based Hall sensors were developed using secondary data in order to understand their behavior under strong magnetic fields. Given a device geometry and charge carrier density and mobility, the models accurately calculated sensor resistance, Hall voltage under a normally-incident constant magnetic field, and expected offset from a population of Hall devices. The model was successfully matched against data from integrated chip Hall sensors from St. Jude Medical. Additionally, the feasibility of creating Hall effect devices with common carbon ink was explored experimentally. The material properties obtained from testing these ink-based devices through the …

Wavelength Accuracy Study For High-Density Fiber Bragg Grating Sensor Systems Using A Rapidly-Swept Akinetic-Laser Source, Jacob Egorov

Master's Theses

This thesis studies the center wavelength accuracy of a Fiber Bragg Grating Sensor system that has a large number of sensor elements both as a function of wavelength and as a function of position. Determining the center wavelength of each of the fiber optic sensors is a critical parameter that ultimately determines sensor accuracy. The high density environment can result in degradation of accuracy of the center wavelength measurement. This thesis aims to quantify this measurement error both with theoretical and experimental studies.

There are many sensing applications where optical fiber sensors are preferred over electrical sensors, such as the …

Analysis Of Electromagnetic Launcher Design And Modeling, Garrett Ross Germany

Master's Theses

This thesis derives working expressions from electromagnetic physical laws to gain a deeper understanding of the nature of railguns. The expressions are refined for ease of use and then compared to electromagnetic simulators that solve complex equations that arise from different rail geometry. Further simplifications lead to an expression for the final velocity of the projectile and showcase the importance of the system resistance to projectile flux gain ratio. A Simulink simulation then incorporates the resulting non-linear differential equations and approximates the projectile velocity over time based on physical dimensions and material properties. Some equations derived can be found in …

Scaled Synthetic Aperture Radar System Development, Ryan K. Green

Master's Theses

Synthetic Aperture Radar (SAR) systems generate two dimensional images of a target area using RF energy as opposed to light waves used by cameras. When cloud cover or other optical obstructions prevent camera imaging over a target area, SAR can be substituted to generate high resolution images. Linear frequency modulated signals are transmitted and received while a moving imaging platform traverses a target area to develop high resolution images through modern digital signal processing (DSP) techniques. The motivation for this joint thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Objectives include …

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …