Electromagnetics and Photonics Commons^™

Archimedean Spiral Antenna Array With Klopfenstein And Exponential Tapered Balun Feeds, Leo Joseph Alvelais Iv, Paul Obrecht, Naguib Abdulla, Preston Mavady, Collin Fan

Electrical Engineering

This project presents the design, fabrication, and experimental evaluation of a broadband 3x3 Archimedean spiral antenna array tile for 2.8-3.8 GHz. Each element combines a two-arm spiral on Rogers RO4350B, a printed 50 to 150 Ω tapered balun, and a conductive backplane. Klopfenstein and Exponential feed implementations were modeled in Ansys HFSS, generated and tuned with automated scripting, fabricated, and evaluated with calibrated network and anechoic-chamber measurements. The Klopfenstein-fed hardware met the -10 dB input-reflection criterion across the project band. The exponential array provided a broad matched response but reached approximately -8 dB near 2.95 GHz. Measured center-element patterns retained …

Evaluation Of Laser Doppler Flowmetry And Transillumination Laser Speckle Contrast Imaging To Measure Blood Flow Change In Ischemia Mouse Hindlimb Models, Simon Park

Master's Theses

Peripheral Artery Disease (PAD), caused by plaque buildup and narrowing of the arteries, reduces blood flow to the extremities. Promoting collateral arteriogenesis can help redirect blood flow. However, simple growth of collaterals may not be enough to reverse PAD. Instead, the ability for the collaterals to vasodilate and control blood flow is important, meaning assessing collateral function is important for the arteriogenesis assesment. Although microscopy techniques can measure vasodilation, contrast limitations in larger vessels such as collaterals make blood flow measurements difficult. Techniques such as ultrasound or magnetic resonance imaging (MRI) can measure blood flow but have limitations with cost …

Foundation For A Digital Beamforming System Using Software Defined Radio, Daniel Cruz Guerrero, Shiron Bendrihem, Benjamin Tucker

Electrical Engineering

This report demonstrates a basis for the foundation of a software-defined radio (SDR)-based digital beam forming system. Specifically, a discussion of time, frequency, and phase synchronization is had in the absence of costly hardware like an OctoClock. Furthermore, this report digs deep into the design process and device characterization of a 4-way Wilkinson Power Divider, which is a necessary hardware component for phase calibration. SDR synchronization and calibration are critical in any digital beamforming system.

A Broadband, Dual Polarized Antenna For The Radio Neutrino Observatory In Greenland, Laken Baker

Electrical Engineering

Neutrinos contain information necessary to determine the origins of the universe and cosmic events because they can travel long distances with minimal interaction, preserving information about their cosmic origins. Since neutrinos interact with ice sheets resulting in RF radiation, antennas have been developed to detect RF transmissions.

A compact 'vane structure' (see Fig. 1a) dual-polarized broadband antenna model has been developed, constructed, and characterized according to input reflection coefficient, and co and cross-pol E and H plane radiation patterns using HFSS and Cal Poly San Luis Obispo’s anechoic chamber for the Radio Neutrino Observatory in Greenland (RNO-G) [1]. Its design …

Alford Loop Antennas For Ultra-High Energy Neutrino Detection, John K. Kimura

Master's Theses

The neutrino is a fundamental particle of matter emitted by high energy phenomena, such as supernovae and black holes. Detecting neutrinos can give scientists information regarding the frequency of high-energy cosmic events, as well as point them towards specific high-energy events. Ultra-high energy (UHE) neutrino interactions in Greenland ice result in electromagnetic pulses between 200MHz and 800MHz. The Radio Neutrino Observatory - Greenland (RNO-G) seeks to observe the resultant electromagnetic waves. The Alford Loop antenna is proposed to detect these emissions, because of its dipole-like radiation pattern, horizontal polarization, and adequate dimensions to fit in a 10" diameter ice borehole. …

Analysis And Design Of A 2-Bit Millimeter-Wave Reconfigurable Intelligent Surface And Investigation Of Fss-Assisted Angular Stability, Max Spalek

Master's Theses

Millimeter-Wave (mm-wave) technology utilizes high frequency spectrum and can deliver multi-gigabit speeds, ultra-low latency, and massive bandwidth capacity. However, this technology is rather new and many technical challenges remain. On the other hand, Reconfigurable Intelligent Surfaces (RIS) have emerged as promising structures for controllable electromagnetic wavefront manipulation in wireless communication systems. This thesis presents the design of a 2-bit RIS unit-cell element operating throughout the 30–34 GHz mm-wave band, where the structure was progressively refined from an initial resonating geometry toward a grounded reflective RIS configuration. The proposed structure utilizes PIN-diode switching states to produce four discrete reflected phase states …

Photophoretic Optical Particle Trapping Improvements Using Beam Reflection, Ian A. Garcia, Xiaomin Jin Phd., Kun Hua Phd.

Master's Theses

Current research has shown that photophoretic optical trapping (POT) is a promising method for creating true three-dimensional holograms. A landmark study by Smalley et. al. at BYU was able to generate a full hologram within a 2 cm edge cube with remarkable success. However, a key drawback to this method is its poor ability to hold trapped particles within the focal point of the laser for an extended period of time. An investigation from our group presented at SPIE Photonics West 2023 sought to improve these results by varying the focal length of the trapping and the wavelength of the …

A Broadband, Dual Polarized Antenna For The Radio Neutrino Observatory In Greenland, Danny Maas

Master's Theses

The Radio Neutrino Observatory in Greenland (RNO-G) is a multidisciplinary, multinational collaboration which uses antennas to detect neutrino interactions with arctic ice sheets. Neutrinos are formed from nuclear reactions; predominant sources include nuclear reactors, stars, supernovae, and the big bang. They rarely interact with normal matter and thus travel from origin to destination relatively unimpeded, with applications including tracking nuclear weapons tests and supernovae. Measurements of galactic neutrino flux can provide information about how the universe developed and its current evolution. Neutrino interactions produce signals from 100 to 1000MHz. Current RNO-G antennas operate over only a portion of this band; …

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 …

Multi-Hop And Automated Testing Of Wide-Area Network Radio Systems, Zachary C. Numa, Joseph S. Nuccio

Electrical Engineering

Requests for low-power and versatile wide-area Internet-of-Things (IoT) networks are becoming more prevalent with upcoming research in low-data rate ad-hoc mesh networks. Connections to terrestrial satellites have proven promising methods for increasing range capabilities for wide area networks (WAN). As research in communication with IoT networks and satellites progresses, reliable multi-hop mesh networks for Earth-based communication are still necessary to develop the base for satellite communication. These multi-hop communication mesh networks are being developed to allow communication where Line-of-Sight (LOS) from A to B is incapable due to environmental barriers. Hence, communication is possible without LOS by providing an intermediate …

2-Bit Schiffman Phase Shifter, Tavita Dayton, Enrique Ruiz

Electrical Engineering

Phase shifters are found in microwave/RF applications such as defense or wireless communications for their ability to control the relative phase of a system which allows for alignment of signals to obtain constructive interference. Typical phase shifters are chip level (digital and analog) which require a DC bias therefore restricting PCB use unless allowance for air gaps. The paper analyzes a passive and low-profile 2-bit phase shifter using the Schiffman architecture, which outputs a near-constant 90 degree shift over a wide band of frequencies. The design process initially confirmed a proper 90 degree phase shift over the desired WiFi band, …

Design And Characterization Of A Broadband Rf Switch Utilizing Surface Mount Devices, Daniel Bracamontes

Master's Theses

High frequency solid-state switches are critical elements in communication systems, radio frequency (RF) systems and instrumentation. Key parameters to an RF switch include insertion loss while on and off-state isolation. Power handling and linearity are important to consider for a cost-effective construction. This becomes a design challenge into K-band frequencies as components required need to be small, dielectric losses and transmission lines need to be physically matched for proper isolative and through states. This thesis presents a novel single pole eight throw (SP8T) hybrid design composed of commercially available surface mount technology solutions to achieve high isolation and low insertion …

High Performance Radar System, Danny Maas

Electrical Engineering

This report covers the design, fabrication, and test of an X-band FMCW radar inspired by the radars from Cal Poly course EE 541, “Advanced Microwave Laboratory.” In this class, 2.4GHz Doppler and FMCW radars are designed and built using consumer off-the-shelf (COTS) components. Operability is the focus of this class, sacrificing performance, accuracy, and precision. this project aims to improve upon those radars by using custom-designed components instead of COTS components and shifting the operating frequency to 10GHz.. The use of custom components can improve output power and frequency stability, and higher frequency reduces component size. The FCC allows amateur …

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 …

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 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 …

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 …

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) …

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 …

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 …

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.

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 …