Semiconductor Photonic Crystal Surface Emitting Lasers For High Power, High Brightness And High Speed Applications,
2024
University of Texas at Arlington
Semiconductor Photonic Crystal Surface Emitting Lasers For High Power, High Brightness And High Speed Applications, Chhabindra Gautam
Electrical Engineering Dissertations - Archive
Photonic Crystal Surface Emitting Laser (PCSEL) is the promising third generation semiconductor laser technology as it addresses the challenges of the conventional semiconductor lasers (EEL/VCSEL) by providing single mode high power output with good beam quality (thus high brightness). The large area in plane coupling resulting from the multiple Bragg’s diffraction conditions in the periodic 2D photonic crystal cavities in the lasing cladding region leads to single mode operation over very large area. By model design engineering, such in plane lasing cavity can leak the light out of the plane, which result in surface emission. The ability to scale the …
Analysis And Design Of Multiport Converters For Photovoltaic And Electrical Vehicle Applications,
2024
University of Central Florida
Analysis And Design Of Multiport Converters For Photovoltaic And Electrical Vehicle Applications, Reza Rezaii
Graduate Thesis and Dissertation 2023-2024
The widespread adoption of photovoltaic (PV) and electric vehicle (EV) technologies is crucial for mitigating greenhouse gas emissions. A Multi-Port Converter (MPC) connects multiple PV panels, improving efficiency and reducing costs. In EVs, MPCs extend battery lifespan by adding energy sources, enhancing system quality beyond reliance on Li-ion batteries. This dissertation proposes a Quad-input LLC topology for PV microinverters. It utilizes a single LLC resonant tank and two Y switches configurations. An MPPT control strategy based on Perturb and Observe (P&O) method ensures independent MPPT for each panel. The zero-voltage switching (ZVS) is achieved across all switches for wide input …
Hyperspectral And Polarimetric Imaging Of The Ocean For The Characterization Of The Surface Effects And Measurement Uncertainties,
2024
CUNY City College
Hyperspectral And Polarimetric Imaging Of The Ocean For The Characterization Of The Surface Effects And Measurement Uncertainties, Mateusz Malinowski
Dissertations and Theses
Ocean and coastal waters are monitored by Ocean Color satellite sensors to determine concentrations of chlorophyll and water properties and identify areas of algal blooms and other events. The light radiance from the ocean is weak in comparison with the sky radiance, which requires very accurate atmospheric correction of the radiance measured at the top of the atmosphere (TOA) on the satellite and heavy validation of the derived water leaving radiance by field measurements from the ships and ocean platforms. For TOA and especially above water radiance the skylight reflected from the ocean surface represents one of the main sources …
Enabling Hybrid Optical-Microwave Space Communications With Optically Transparent Rf Components Using Indium Tin Oxide (Ito),
2024
Embry-Riddle Aeronautical University
Enabling Hybrid Optical-Microwave Space Communications With Optically Transparent Rf Components Using Indium Tin Oxide (Ito), John T. O'Keefe
Doctoral Dissertations and Master's Theses
Over the last decade, spacecraft have increasingly integrated both microwave and optical communication systems, driving the need for electrically conductive and optically transparent materials. This study presents a comprehensive examination of advanced electromagnetic characterization techniques and the design, fabrication, and performance of optically transparent antennas using Indium Tin Oxide (ITO) films on alkaline earth boro-aluminosilicate glass for transparent radio-frequency (RF) applications in space communication systems. Addressing the limitations of traditional metal-based antennas—particularly their shadowing effect on satellite solar cells—this study investigates ITO as a pivotal material for creating antennas that are both efficient in communication and non-intrusive to solar efficiency. …
Gas Assisted Electron Beam Patterning Processes,
2024
University of Kentucky
Gas Assisted Electron Beam Patterning Processes, Deepak Kumar
Theses and Dissertations--Electrical and Computer Engineering
Radiolysis is a complex phenomenon in which molecules subjected to ionizing radiation form new chemical species. Electron-beam irradiation has proven to be a versatile approach for significantly altering materials’ properties and forms the basis for electron-beam lithography using both organic and inorganic resists. Electron-beam exposure is normally carried out under high vacuum conditions to reduce contamination and allow for unhindered interaction between the electrons and the resist material. Exposure under an ambient gas at sub-atmospheric pressures has been found to provide a distinct mechanism which can be exploited to circumvent some of the challenges associated with material processing and significantly …
Reinventing Integrated Photonic Devices And Circuits For High Performance Communication And Computing Applications,
2024
University of Kentucky
Reinventing Integrated Photonic Devices And Circuits For High Performance Communication And Computing Applications, Venkata Sai Praneeth Karempudi
Theses and Dissertations--Electrical and Computer Engineering
The long-standing technological pillars for computing systems evolution, namely Moore's law and Von Neumann architecture, are breaking down under the pressure of meeting the capacity and energy efficiency demands of computing and communication architectures that are designed to process modern data-centric applications related to Artificial Intelligence (AI), Big Data, and Internet-of-Things (IoT). In response, both industry and academia have turned to 'more-than-Moore' technologies for realizing hardware architectures for communication and computing. Fortunately, Silicon Photonics (SiPh) has emerged as one highly promising ‘more-than-Moore’ technology. Recent progress has enabled SiPh-based interconnects to outperform traditional electrical interconnects, offering advantages like high bandwidth density, …
Photoluminescence Switching In Quantum Dots Connected With Fluorinated And Hydrogenated Photochromic Molecules,
2024
University of Virginia
Photoluminescence Switching In Quantum Dots Connected With Fluorinated And Hydrogenated Photochromic Molecules, Ephraiem S. Sarabamoun, Jonathan M. Bietsch, Pramod Aryal, Amelia G. Reid, Maurice Curran, Grayson Johnson, Esther H. R. Tsai, Charles W. Machan, Guijun Wang, Joshua J. Choi
Chemistry & Biochemistry Faculty Publications
We investigate switching of photoluminescence (PL) from PbS quantum dots (QDs) crosslinked with two different types of photochromic diarylethene molecules, 4,4'-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (1H) and 4,4'-(1-perfluorocyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (2F). Our results show that the QDs crosslinked with the hydrogenated molecule (1H) exhibit a greater amount of switching in photoluminescence intensity compared to QDs crosslinked with the fluorinated molecule (2F). With a combination of differential pulse voltammetry and density functional theory, we attribute the different amount of PL switching to the different energy levels between 1H and 2F molecules which result in different potential barrier …
A Method For Measuring The Transfer Function Inside A Compact Metallic Enclosure Using A Slot Antenna,
2024
Missouri University of Science and Technology
A Method For Measuring The Transfer Function Inside A Compact Metallic Enclosure Using A Slot Antenna, Xiangrui Su, Wenchang Huang, Junghee Cho, Joonki Paek, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
Radio frequency desensitization issues comprise two components: noise radiation sources and the transfer function from noise sources to the victim antenna. For modern electronic products, noise sources are often located inside a compact metal enclosure, making it difficult to measure the transfer function using conventional methods. Moreover, opening the metallic enclosure would dramatically change the transfer function, and inserting a near-field probe into the enclosure is challenging and may not even be possible because of the limited space inside. In this article, a novel practical method for measuring the transfer function inside a compact metallic enclosure is proposed and experimentally …
Design Of Experiment Analysis On Multiple Pim Sources In An Rf Antenna System,
2024
Missouri University of Science and Technology
Design Of Experiment Analysis On Multiple Pim Sources In An Rf Antenna System, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
Passive intermodulation (PIM) has been identified as one of the common root causes for receiving sensitivity degradation (desense) on radiofrequency (RF) antennas working in frequency-division duplex mode. The component-level PIM characterization and simulation have been well-established over the years. However, the study has been using an ideal 50 Ω transmission line system while antenna modules are more complicated than a simple transmission line structure. Moreover, the metallic contacts can exist in multiple locations with different connection topologies in real applications. This paper provides a method to simulate the PIM performance caused by the metallic contacts in a practical environment. In …
Radiated Emission Modeling Of A Wireless Power Transfer System,
2024
Missouri University of Science and Technology
Radiated Emission Modeling Of A Wireless Power Transfer System, Hanyu Zhang, Guanghua Li, Viswa Pilla, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
A radiated emission (RE) model of a wireless power transfer (WPT) system is proposed in this paper to help designers predict, analyze, and mitigate the RE issues during the design process. The proposed model employs both full-wave simulation and circuit simulation to derive a transfer function. Subsequently, it predicts the emission level by combining the transfer function with the measured transmitter waveform through a straightforward calculation. The predicted emissions match the measured RE peaks well up to 300 MHz, with the error within 3 dB. The impact of functional parameters, such as load and coil gap distance, is analyzed based …
Vertical Interconnect Technology In Silicon, Package, And Printed Circuit Board (Pcb) With Coaxial Structure,
2024
Missouri University of Science and Technology
Vertical Interconnect Technology In Silicon, Package, And Printed Circuit Board (Pcb) With Coaxial Structure, Junyong Park, Chaofeng Li, Eddie Mok, Joe Dickson, Joan Tourne, Donghyun Kim
Electrical and Computer Engineering Faculty Research & Creative Works
This paper introduces vertical interconnect technology in silicon, package, and printed circuit board (PCB) levels with a coaxial structure, respectively. The coaxial structure has been known to be advantageous in terms of signal integrity (SI) compared to the non-coaxial structure. The coaxial structure is easy to control the characteristic impedance Z0 and robust to crosstalk. The silicon-level interconnect includes the wire bonding (WB) and through-silicon via (TSV) technology, the package-level interconnect includes an elastomer package test socket. The PCB-level interconnect includes the vias, and vertical conductive structure (VeCS). For each level, the non-coaxial and coaxial interconnects are compared with the …
Design Of The Tm010 Mode Cylindrical Cavity Resonator For Pcb Dielectric Characterization,
2024
Missouri University of Science and Technology
Design Of The Tm010 Mode Cylindrical Cavity Resonator For Pcb Dielectric Characterization, Reza Asadi, Chaofeng Li, Seyedmehdi Mousavi, Seyed Moastafa Mousavi, Reza Vahdani, Xiaoning Ye, Donghyun Kim
Electrical and Computer Engineering Faculty Research & Creative Works
This paper presents the study of the TM010 mode cylindrical resonator, which can be used for printed circuit board (PCB) material properties extraction, e.g., the dielectric constant (Dk) and the loss tangent (Df) extraction. The theoretical formulas of the resonance frequency and Q-factor of the resonator are presented. In real measurement, the TM010 mode cylindrical cavity resonator needs to be excited by the probe. The study emphasizes the impact of probe orientation, location, and field distribution on the accuracy of material property extraction. The relationship between cavity dimensions and resonance frequency is explored, highlighting the influence of cavity …
Novel Formulation For Generalization Of Mixed-Mode S-Parameters For Coupled Differential High-Speed Digital Channels,
2024
Missouri University of Science and Technology
Novel Formulation For Generalization Of Mixed-Mode S-Parameters For Coupled Differential High-Speed Digital Channels, Manish K. Mathew, Kevin Cai, Chaofeng Li, Mehdi Mousavi, Shameem Ahmed, Donghyun Kim
Electrical and Computer Engineering Faculty Research & Creative Works
As the demand for higher data rates intensifies, achieving accurate S-parameter calculation becomes increasingly critical. The conventional single-ended to mixed-mode S-parameter conversion formulation assumes uncoupled structures, which may not be true for high-speed digital channels. This work introduces a novel, generalized formulation for mixed-mode S-parameters and their corresponding transformation matrices [M1] and [M2], enabling comprehensive analysis of multi-pair coupled differential traces. An intra-pair crosstalk analysis of a tightly coupled strip line and microstrip line verifies and highlights the difference between the proposed and old formulations. A loosely coupled case is analyzed as an additional validation of the proposed formulation. Finally, …
High-Speed Channel Simulator Using Neural Language Models,
2024
Missouri University of Science and Technology
High-Speed Channel Simulator Using Neural Language Models, Hyunwook Park, Yifan Ding, Ling Zhang, Natalia Bondarenko, Hanqin Ye, Brice Achkir, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, high-speed channel simulators using neural language models are proposed. Given the input sequence of geometry design parameters of differential channels, the proposed channel simulator predicts SI characteristic sequences such as insertion loss (IL) and far-end crosstalk (FEXT). Sequence-to-sequence (seq2seq) networks using a recurrent neural network (RNN) and a long short-term memory (LSTM) are utilized for the estimator. Moreover, a transformer network which is a recent neural engine of large language models (LLMs) is introduced for the first time. Compared to seq2seq networks, the transformer network-based simulator can achieve shorter computing time due to its parallel computation called …
Experimental Study Of Pcb Vibration Induced By Mlcc Assembly Orientation And Process Variations,
2024
Missouri University of Science and Technology
Experimental Study Of Pcb Vibration Induced By Mlcc Assembly Orientation And Process Variations, Yifan Ding, Ming Feng Xue, Jianmin Zhang, Xin Hua, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
The piezoelectric effect will cause the multilayer ceramic capacitor (MLCC) to deform in several directions. When it is soldered to the printed circuit board (PCB) and powered on, these deformations will exert a certain force on the PCB, causing the PCB to vibrate and emit acoustic noise at a certain frequency. Determining the dominant deformation direction that MLCC can affect the PCB is relevant and important for efficiently extracting the equivalent source of noise. This paper provides a method to determine the dominant deformation direction produced by MLCC, explores it through experimental measurement results, and finally provides a conclusion to …
Design Of Waveguide Probe For Emi Characterization Of Ddr5 Sodimm,
2024
Missouri University of Science and Technology
Design Of Waveguide Probe For Emi Characterization Of Ddr5 Sodimm, Xiangrui Su, Junho Joo, Minsu Lee, Jeongho Ju, Hyunsik Kim, Taeil Bae, Haekang Jung, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
In the latest portable electronic devices, 5th generation double data rate small outline dual in-line memory modules (DDR5 SODIMMs) are more and more used and have been identified as one of the critical electromagnetic interferences (EMI) noise sources that could cause RF desensitization. In this paper, the radiation mechanism of DDR5 SODIMM deployed in a laptop is identified and investigated based on near-field scanning. It was found that a cavity formed by the SODIMM and the main board can generate strong radiation around 2.4 GHz due to their dimensions, which overlap with the Wi-Fi band. To quantify the radiation from …
Behavior Model Of A Multiphase Voltage Regulator Module With Rapid Voltage Drop Protection,
2024
Missouri University of Science and Technology
Behavior Model Of A Multiphase Voltage Regulator Module With Rapid Voltage Drop Protection, Junho Joo, Hanyu Zhang, Hanfeng Wang, Wei Shen, Zhigang Liang, Lihui Cao, Seungtaek Jeong, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, a modeling method of voltage regulator module (VRM) with rapid voltage drop protection is introduced. The proposed VRM model captures a pulse-width modulation scheme developed to counteract substantial load currents with high di/dt, resulting in a large voltage drop across the power delivery network (PDN). The equations to describe the non-linear behavior associated with the multiphase VRM behavior are proposed and successfully validated for both light and heavy loads, the latter being particularly crucial to trigger the voltage drop protection measures.
Dk And Df Characterization Of Low-Loss Dielectric Liquid By Cylindrical Cavity Resonator,
2024
Missouri University of Science and Technology
Dk And Df Characterization Of Low-Loss Dielectric Liquid By Cylindrical Cavity Resonator, Chaofeng Li, Seyedmehdi Mousavi, Reza Asadi, Seyedmostafa Mousavi, Reza Vahdani, Xiaoning Ye, Kai Wang, Donghyun Kim
Electrical and Computer Engineering Faculty Research & Creative Works
A novel cylindrical cavity resonator-based measurement method was developed to characterize the dielectric property of the low-loss dielectric liquid in the paper. The proposed method can be used to accurately measure the dielectric constant (Dk) and the loss tangent (Df) of the low-loss coolant for signal integrity analysis. The cylindrical cavity resonator works at tangential magnetic (TM010) mode is used in the paper to demonstrate the proposed method. A cylindrical cavity resonator apparatus was designed and investigated using full-wave simulations at first. The relative error of Dk and Df extractions based on the designed apparatus are less than 1% and …
Modeling Of Power Distrubition Network (Pdn) Noise Coupling Induced Clock Phase Noise,
2024
Missouri University of Science and Technology
Modeling Of Power Distrubition Network (Pdn) Noise Coupling Induced Clock Phase Noise, Zhekun Peng, Junyong Park, Chaofeng Li, Joey Stecher, Srinivas Venkataraman, Xu Wang, Granthana Rangaswamy, Donghyun Kim
Electrical and Computer Engineering Faculty Research & Creative Works
Phase noise analysis is important to clock design. Noise sources of spurs shown on the phase noise result are challenging to find out due to the unknown source locations and coupling mechanisms. Noise from power distribution network (PDN) is one of the most troublesome sources. A behavioral modeling methodology is proposed to simulate the clock phase noise induced by PDN noise coupling for two different mechanisms: PDN-to-clock additive coupling and PDN-to-PDN up-conversion modulation. The thermal noise and 1/f flicker noise are simplified to provide a straightforward view of spur level. The model can be applied to both single-ended clock and …
Graph Convolutional Neural Network Assisted Genetic Algorithm For Pdn Decap Optimization,
2024
Missouri University of Science and Technology
Graph Convolutional Neural Network Assisted Genetic Algorithm For Pdn Decap Optimization, Haran Manoharan, Jack Juang, Ling Zhang, Hanfeng Wang, Jingnan Pan, Kelvin Qiu, Xu Gao, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
This paper proposes a hybrid algorithm combining reinforcement learning (RL) and a genetic algorithm (GA) for PDN decap optimization. The trained RL agent uses a graph convolutional neural network as a policy network and predicts the decap solution for a given PDN impedance and target impedance, which is seeded as an initial population to the GA. The trained RL agent is scalable regarding the number of decap ports. The main goal is to save computation time and find the near global minimum or global minimum. Generalization of the algorithm to different decap libraries is achieved through transfer learning, eventually reducing …
