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Electrical and Computer Engineering Faculty Research & Creative Works

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A Deep Learning Approach To Design And Discover Sustainable Cementitious Binders: Strategies To Learn From Small Databases And Develop Closed-Form Analytical Models, Taihao Han, Sai Akshay Ponduru, Rachel Cook, Jie Huang, Gaurav Sant, Aditya Kumar Jan 2022

A Deep Learning Approach To Design And Discover Sustainable Cementitious Binders: Strategies To Learn From Small Databases And Develop Closed-Form Analytical Models, Taihao Han, Sai Akshay Ponduru, Rachel Cook, Jie Huang, Gaurav Sant, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

To reduce the energy-intensity and carbon footprint of Portland cement (PC), the prevailing practice embraced by concrete technologists is to partially replace the PC in concrete with supplementary cementitious materials [SCMs: geological materials (e.g., limestone); industrial by-products (e.g., fly ash); and processed materials (e.g., calcined clay)]. Chemistry and content of the SCM profoundly affect PC hydration kinetics; which, in turn, dictates the evolutions of microstructure and properties of the [PC + SCM] binder. Owing to the substantial diversity in SCMs' compositions–plus the massive combinatorial spaces, and the highly nonlinear and mutually-interacting processes that arise from SCM-PC interactions–state-of-the-art computational models are …


Improving Virtual Synchronous Generator Control In Microgrids Using Fuzzy Logic Control, Oroghene Oboreh-Snapps, Rui Bo, Buxin She, Fangxing Fran Li, Hantao Cui Jan 2022

Improving Virtual Synchronous Generator Control In Microgrids Using Fuzzy Logic Control, Oroghene Oboreh-Snapps, Rui Bo, Buxin She, Fangxing Fran Li, Hantao Cui

Electrical and Computer Engineering Faculty Research & Creative Works

Virtual synchronous generators (VSG) are designed to mimic the inertia and damping characteristics of synchronous generators (SG), which can improve the frequency response of a microgrid. Unlike synchronous generators whose inertia and damping are restricted by the physical characteristics of the SG, VSG parameters can be more flexibly controlled to adapt to different disturbances. This paper therefore proposes a fuzzy logic controller designed to adaptively set the parameters of the VSG during a frequency event to ensure an improved frequency nadir and rate of change of frequency (ROCOF) response. The proposed control method is implemented and tested on the power …


Hamiltonian-Driven Adaptive Dynamic Programming With Efficient Experience Replay, Yongliang Yang, Yongping Pan, Cheng Zhong Xu, Donald C. Wunsch Jan 2022

Hamiltonian-Driven Adaptive Dynamic Programming With Efficient Experience Replay, Yongliang Yang, Yongping Pan, Cheng Zhong Xu, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a novel efficient experience-replay-based adaptive dynamic programming (ADP) for the optimal control problem of a class of nonlinear dynamical systems within the Hamiltonian-driven framework. The quasi-Hamiltonian is presented for the policy evaluation problem with an admissible policy. With the quasi-Hamiltonian, a novel composite critic learning mechanism is developed to combine the instantaneous data with the historical data. In addition, the pseudo-Hamiltonian is defined to deal with the performance optimization problem. Based on the pseudo-Hamiltonian, the conventional Hamilton–Jacobi–Bellman (HJB) equation can be represented in a filtered form, which can be implemented online. Theoretical analysis is investigated in terms …


Analysis Of Switching Voltage Regulator Noise Coupling To A High-Speed Signal, Junho Joo, Soumya Singh, P. K. Seema, Chulsoon Hwang, Bhyrav Mutnury, James L. Drewniak Jan 2022

Analysis Of Switching Voltage Regulator Noise Coupling To A High-Speed Signal, Junho Joo, Soumya Singh, P. K. Seema, Chulsoon Hwang, Bhyrav Mutnury, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a real-world signal and power integrity problem due to the switching noise of buck converter IC coupling to a high-speed signal line in a server system is studied. The rapid switching field effect transistors (FETs) of the voltage regulator module (VRM) are the main source of the performance degradation on the nearby signal lines. A simplified mock-up simulation setup is proposed based on the actual board design to investigate the coupling mechanism of the VRM noise. The mechanism of the switching noise coupling is explained with the phenomenon of capacitive and inductive coupling. Based on this finding, …


Fixture Design For Parasitic Capacitances Of Mosfets For Emi Applications, Anfeng Huang, Hanyu Zhang, Li Du, Cheung Wei Lam, Chulsoon Hwang Jan 2022

Fixture Design For Parasitic Capacitances Of Mosfets For Emi Applications, Anfeng Huang, Hanyu Zhang, Li Du, Cheung Wei Lam, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the fast-switching nature of modern power converters, up to hundreds of MHz of common-mode noise can easily be generated. The characterization of switching components, e.g., Si MOSFETs, is essential for noise reduction. However, limited by the bandwidth of instruments, the voltage-dependent capacitances of high voltage MOSFETs are typically characterized at approximately 1 MHz, which is insufficient for EMI applications. In this paper, the measurement method and the test fixtures are presented. The measurement bandwidth is pushed to 30 MHz and higher, and frequency-dependent capacitances of a MOSFET are observed through measurements.


An Interleaved High Step-Up Dc-Dc Converter With Built-In Transformer-Based Voltage Multiplier For Dc Microgrid Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi Jan 2022

An Interleaved High Step-Up Dc-Dc Converter With Built-In Transformer-Based Voltage Multiplier For Dc Microgrid Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a high step-up DC-DC converter with a built-in transformer (BIT)-based voltage multiplier (VM) that is suitable for integrating low-voltage renewable energy sources into a DC microgrid. A three-winding BIT is combined with the switched-capacitor (SC) cells to extend the voltage gain and reduce the voltage stress on the switches. The current-falling rates of the diodes are controlled by the leakage inductances of the BIT, alleviating the reverse-recovery problem of the diodes. The operating modes and steady-state analysis are presented. Additionally, the validity of the proposed converter is confirmed by the simulation and experimental results of a 400 …


Analysis Of The Shielding Effectiveness Of Chassis Based On Dgtd Method, Zheng Lang Jia, Lei Zhao, Zhao Sheng Xue, Ying Liu, Huan Huan Zhang, L. (Lijun) J. Jiang Jan 2022

Analysis Of The Shielding Effectiveness Of Chassis Based On Dgtd Method, Zheng Lang Jia, Lei Zhao, Zhao Sheng Xue, Ying Liu, Huan Huan Zhang, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

An electromagnetic simulation method is proposed for shielding effectiveness (SE) of chassis in this paper. The discontinuous Galerkin time-domain (DGTD) equation is established based on Maxwell's equation. The uniaxial perfectly matched layer (UPML) is used as an absorbing boundary condition to simulate an open space. At last, the method is applied to analyze the effect of the aspect ratios of rectangular apertures on shielding effectiveness.


Modeling Radiated Emissions From Pcbs In Shielding Enclosures Based On A Numerical Green's Function Approach, Zi An Wang, Li (Lijun) Jun Jiang, Jun Fa Mao, Ping Li Jan 2022

Modeling Radiated Emissions From Pcbs In Shielding Enclosures Based On A Numerical Green's Function Approach, Zi An Wang, Li (Lijun) Jun Jiang, Jun Fa Mao, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

To accurately and efficiently model the radiated emissions from printed circuit boards (PCBs) placed in shielding enclosures, in this work, a novel approach based on the numerical Green's function (NGF) is proposed. In terms of Schelkunoff's equivalence principle, if the interior of the shielding enclosure is filled up with perfectly electric conductor (PEC), only tangential electric fields over the ventilation slots are sufficient to obtain the radiated emissions. However, due to the presence of the PEC filled shielding box, the in-situ Green's function is not available. To conquer this problem, the proposed approach can be split into two steps. In …


Graphene-Based Terahertz Holographic Conformal Antenna, Peng Fei Ren, Li (Lijun) Jun Jiang, Ping Li Jan 2022

Graphene-Based Terahertz Holographic Conformal Antenna, Peng Fei Ren, Li (Lijun) Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a conformal graphene holographic antenna designed for terahertz (THz) band is proposed. The radiation principle of the proposed pattern reconfigurable antenna is based on the holographic technology. The surface reactance modulation and pattern steering capability can be easily facilitated by a tunable DC-biased graphene patch array. Thanks to the super thin structure and excellent mechanical property of graphene, the proposed THz graphene holographic antenna can be designed conformal to required platforms easily. Besides, the equal size as well as same spacing of graphene patches make it easy to modeling and manufacture. To verify the proposed idea, an …


Modeling Of Spatial-Temporal Sea Clutter With I/Q Components Based On The Data-Driven Approximation Of Koopman Theory, Y. M. Zhang, L. (Lijun) J. Jiang Jan 2022

Modeling Of Spatial-Temporal Sea Clutter With I/Q Components Based On The Data-Driven Approximation Of Koopman Theory, Y. M. Zhang, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel data-driven approximation of the Koopman theory algorithm is proposed to simulate the coherent and spatial-temporal correlated sea clutter. The evolution of sea clutter's in-phase and quadrature (I/Q) components are well simulated on the state space. Meanwhile, the amplitude distribution and the phase retrieval of sea clutter can be extracted and modeled. The experimental sea clutter data measured by the IPIX radar is used to demonstrate that this newly proposed data-driven approximation of the Koopman theory algorithm can simulate the sea clutter with the phase retrieval, the expected amplitude information, and the spatial-temporal relationship. Our work …


Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung Jan 2022

Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel method to design a decoupling network (DN) to increase isolation between dual-band antennas. The DN design is based on the scattering matrix and optimized by the Genetic Algorithm (GA). The decoupling example shows that the DN offers impedance matching and high isolation within desired bands, verifying the concept.


Guest Editorial, Ming Yu, Lijun Jiang, Alex M.H. Wong Jan 2022

Guest Editorial, Ming Yu, Lijun Jiang, Alex M.H. Wong

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.


Dc Ir-Drop Analysis Of Power Distribution Networks By A Robin Transmission Condition-Enhanced Discontinuous Galerkin Method, An Fa Yang, Min Tang, Jun Fa Mao, Li (Lijun) Jun Jiang, Hakan Bagcii, Ping Li Jan 2022

Dc Ir-Drop Analysis Of Power Distribution Networks By A Robin Transmission Condition-Enhanced Discontinuous Galerkin Method, An Fa Yang, Min Tang, Jun Fa Mao, Li (Lijun) Jun Jiang, Hakan Bagcii, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, a novel Robin transmission condition (RTC)-enhanced discontinuous Galerkin (DG) method is proposed for the dc IR-drop analysis of power distribution networks with Joule heating effects included. Unlike the conventional DG method, the proposed DG method straightforwardly applied to discretize the second-order spatial partial differential governing equations for the electrostatic potential $\Phi $ and the steady-state temperature $T$. The numerical flux in DG used to facilitate the information exchange among neighboring subdomains introduces two additional variables: the current density $J$ for the electrical potential equation and the thermal flux $q$ for the thermal equation. To solve them, at …


Forecasting Nodal Price Difference Between Day-Ahead And Real-Time Electricity Markets Using Long-Short Term Memory And Sequence-To-Sequence Networks, Ronit Das, Rui Bo, Haotian Chen, Waqas Ur Rehman, Donald C. Wunsch Jan 2022

Forecasting Nodal Price Difference Between Day-Ahead And Real-Time Electricity Markets Using Long-Short Term Memory And Sequence-To-Sequence Networks, Ronit Das, Rui Bo, Haotian Chen, Waqas Ur Rehman, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Price forecasting is at the center of decision making in electricity markets. Much research has been done in forecasting energy prices for a single market while little research has been reported on forecasting price difference between markets, which presents higher volatility and yet plays a critical role in applications such as virtual trading. To this end, this paper takes the first attempt at it and employs novel deep learning architecture with Bidirectional Long-Short Term Memory (LSTM) units and Sequence-to-Sequence (Seq2Seq) architecture to forecast nodal price difference between day-ahead and real-time markets. In addition to value prediction, these deep learning architectures …


Pulsed-Active Microwave Thermography, Logan M. Wilcox, Mathias Bonmarin, Kristen M. Donnell Jan 2022

Pulsed-Active Microwave Thermography, Logan M. Wilcox, Mathias Bonmarin, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is a thermographic nondestructive testing and evaluation technique that utilizes an electromagnetic-based excitation with a subsequent infrared measurement of the surface thermal profile of the material or structure of interest. AMT has been successfully applied to several aerospace and civil infrastructure applications. This work seeks to expand the performance of AMT by incorporating a signal processing technique common to traditional (flash-lamp) thermography, referred to as pulsed thermography (PT). PT operates on the premise of a pulsed excitation, as opposed to a constant or step excitation (ST) over a given time-period that is typical to traditional active …


Early Wildfire Detection Using Uavs Integrated With Air Quality And Lidar Sensors, Doaa Rjoub, Ahmad Alsharoa, Ala'eddin Masadeh Jan 2022

Early Wildfire Detection Using Uavs Integrated With Air Quality And Lidar Sensors, Doaa Rjoub, Ahmad Alsharoa, Ala'eddin Masadeh

Electrical and Computer Engineering Faculty Research & Creative Works

Every year, wildfires burn out countless hectares of lands, resulting in ecological, environmental, and economic damage. This paper presents an energy management system that consists of an unmanned aerial vehicle (UAV) equipped with air quality and light detection and ranging (LiDAR) sensors for monitoring forests and recognizing flames early. We develop a novel approach for autonomous patrolling system. This approach has the advantage of effectively detecting wildfire incidents, while optimizing the energy consumption of the UAV's battery to cover large areas. When a wildfire is detected, the UAV is able to transmit real-time data, such as sensor readings and LiDAR …


Single-Snapshot Localization For Near-Field Ris Model Using Atomic Norm Minimization, Omar Rinchi, Ahmed Elzanaty, Ahmad Alsharoa Jan 2022

Single-Snapshot Localization For Near-Field Ris Model Using Atomic Norm Minimization, Omar Rinchi, Ahmed Elzanaty, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

Reconfigurable intelligent surfaces (RISs) are expected to play a significant role in the next generation of wireless cellular technology. This paper proposes an uplink localization scheme using a single-snapshot solution for user equipment (UE) that is located in the near-field of the RIS. We propose utilizing the atomic norm minimization method to achieve super-resolution localization accuracy. We formulate an optimization problem to estimate the UE location parameters (i.e., angles and distances) by minimizing the atomic norm. Then, we propose to exploit strong duality to solve the atomic norm problem using the dual problem and semidefinite programming (SDP). The RIS is …


Robust Modifications To Model Reference Adaptive Control For Reference Voltage Tracking In A Dual Active Bridge Dc-Dc Converter, Kartikeya J.P. Veeramraju, Alvaro Cardoza, Jagannathan Sarangapani, Jonathan W. Kimball Jan 2022

Robust Modifications To Model Reference Adaptive Control For Reference Voltage Tracking In A Dual Active Bridge Dc-Dc Converter, Kartikeya J.P. Veeramraju, Alvaro Cardoza, Jagannathan Sarangapani, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

Model Reference Adaptive Control (MRAC) is useful for achieving a desired dynamic response with no prior knowledge of system parameters. Traditional MRAC is sensitive to noise in the state variables, leading to adaptation parametric drift. The drift in parameters, if left unchecked, leads to loss of closed loop stability. In power electronic systems, the ripple in the output voltage serves as a bounded noise, which leads to MRAC instability. This drift phenomenon is observed through the simulation and hardware experimentation of a Dual Active Bridge (DAB) converter and mitigated using deadzone modification and σ modification approaches. These two methods are …


New Hybrid Model For Evaluating The Frequency-Dependent Leakage Inductance Of A Variable Inductance Transformer (Vit), Angshuman Sharma, Jonathan W. Kimball Jan 2022

New Hybrid Model For Evaluating The Frequency-Dependent Leakage Inductance Of A Variable Inductance Transformer (Vit), Angshuman Sharma, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

Skin and proximity effects can cause a significant drop in the effective leakage inductance of a transformer when the operating frequency is increased. Although the magnetic image method-based double-2-D model can calculate the low-frequency leakage inductance with sufficient accuracy, it is inherently a frequency-independent model. While Dowell's 1-D model uses frequency-dependent relations to account for both skin and proximity effects, its accuracy is severely affected by the assumed winding geometry. In this paper, a hybrid model is proposed that uses superposition to combine a modified Dowell's model with the double-2-D model. The proposed model is investigated on a variable inductance …


An Interleaved High Step-Up Dc-Dc Converter With Coupled Inductor And Built-In Transformer For Renewable Energy Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi Jan 2022

An Interleaved High Step-Up Dc-Dc Converter With Coupled Inductor And Built-In Transformer For Renewable Energy Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces an interleaved high step-up DC-DC converter with high voltage gain, low voltage stresses on the switches, low current stresses on the components, and continuous input current with low ripple, all of which are beneficial for the renewable energy (RE) applications. The proposed converter is based on the integration of three voltage-boosting (VB) methods: coupled inductor (CI), built-in transformer (BIT), and switched-capacitor (SC) cells. The energies of the leakage inductances of the CIs and BIT are absorbed and recirculated to the output side, which further extends the voltage gain. In addition, the current-falling rates of the diodes are …


A Spline-Based Partial Element Equivalent Circuit Method For Electrostatics, Riccardo Torchio, Maximilian Nolte, Sebastian Schops, Albert E. Ruehli Jan 2022

A Spline-Based Partial Element Equivalent Circuit Method For Electrostatics, Riccardo Torchio, Maximilian Nolte, Sebastian Schops, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

This contribution investigates the connection between Isogeometric Analysis (IgA) and the Partial Element Equivalent Circuit (PEEC) method for electrostatic problems. We demonstrate that using the spline-based geometry concepts from IgA allows for extracting circuit elements without an explicit meshing step. Moreover, the proposed IgA-PEEC method converges for complex geometries up to three times faster than the conventional PEEC approach and, in turn, it requires a significantly lower number of degrees of freedom to solve a problem with comparable accuracy. The resulting method is closely related to the isogeometric boundary element method. However, it uses lowest-order basis functions to allow for …


Chimeranet: U-Net For Hair Detection In Dermoscopic Skin Lesion Images, Norsang Lama, Reda Kasmi, Jason R. Hagerty, R. Joe Stanley, Reagan Harris Young, Jessica Miinch, Januka Nepal, Anand Nambisan, William V. Stoecker Jan 2022

Chimeranet: U-Net For Hair Detection In Dermoscopic Skin Lesion Images, Norsang Lama, Reda Kasmi, Jason R. Hagerty, R. Joe Stanley, Reagan Harris Young, Jessica Miinch, Januka Nepal, Anand Nambisan, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

Hair and ruler mark structures in dermoscopic images are an obstacle preventing accurate image segmentation and detection of critical network features. Recognition and removal of hairs from images can be challenging, especially for hairs that are thin, overlapping, faded, or of similar color as skin or overlaid on a textured lesion. This paper proposes a novel deep learning (DL) technique to detect hair and ruler marks in skin lesion images. Our proposed ChimeraNet is an encoder-decoder architecture that employs pretrained EfficientNet in the encoder and squeeze-and-excitation residual (SERes) structures in the decoder. We applied this approach at multiple image sizes …


Clock Duty Cycle Tuning For Desense Mitigation In Modulation -Involved Cases, Shengxuan Xia, Jun Fan, Chulsoon Hwang Jan 2022

Clock Duty Cycle Tuning For Desense Mitigation In Modulation -Involved Cases, Shengxuan Xia, Jun Fan, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Nowadays consumers' electronic devices are highly integrated, and modules and integrated circuits (ICs) are usually placed close to each other due to the compact size. The modules and ICs may interfere with the radio frequency (RF) antennas and cause desense issues. In recent years, desense caused by direct coupling from the noise sources to the victim RF antennas has been well studied. However, more complicated mechanisms such as modulations between transmitting signals and low-frequency clock or data signals can also result in desense problems, especially in frequency divide duplex (FDD) applications. Typical solutions to desense problems will focus on suppressing …


A Dnn-Ensemble Method For Error Reduction And Training Data Selection In Dnn Based Modeling, Ling Zhang, Da Li, Jiayi He, Bhyrav Mutnury, Bo Pu, Xiao Ding Cai, Chulsoon Hwang, Jun Fan, James L. Drewniak, Er Ping Li Jan 2022

A Dnn-Ensemble Method For Error Reduction And Training Data Selection In Dnn Based Modeling, Ling Zhang, Da Li, Jiayi He, Bhyrav Mutnury, Bo Pu, Xiao Ding Cai, Chulsoon Hwang, Jun Fan, James L. Drewniak, Er Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

Deep neural networks (DNNs) have been widely adopted in modeling electromagnetic compatibility (EMC) problems, but the training data acquisition is usually time-consuming through various simulators. This paper presents a powerful approach using an ensemble of DNN s to effectively reduce the training data size in DNN-based modeling problems. A batch of training data with the largest uncertainties is selected using active learning through the variance among the ensemble of DNNs. Subsequently, a greedy sampling algorithm is applied to select a data subset using diversity. Thus, the proposed method can achieve both uncertainty and diversity in data selection. By averaging the …


A Segmentation Strategy For Structures With Common Mode Coupling, James Hunter, Shengxuan Xia, Aaron Harmon, Mohamed Z.M. Hamdalla, Ahmed M. Hassan, Victor Khilkevich, Daryl G. Beetner Jan 2022

A Segmentation Strategy For Structures With Common Mode Coupling, James Hunter, Shengxuan Xia, Aaron Harmon, Mohamed Z.M. Hamdalla, Ahmed M. Hassan, Victor Khilkevich, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

The level of electromagnetic coupling to electronic devices can vary widely from one device to another. When considering the induced voltage from an incoming plane wave on printed circuit boards (PCBs) and their attached cable harnesses, there is significant variety in the configuration of the devices that could be seen. This encourages the use of segmentation, so that the components of these devices (PCBs, connectors, and harnesses) can be modeled separately to alleviate simulation burden. This allows for a more flexible model and a 'toolbox' to construct devices with. The goal of this work is to use segmentation to model …


High Permittivity Anisotropic 3d Printed Material, Aaron Harmon, Victor Khilkevich, Kristen M. Donnell Jan 2022

High Permittivity Anisotropic 3d Printed Material, Aaron Harmon, Victor Khilkevich, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, the diagonal elements of the permittivity matrix for dielectric samples, 3D printed with a carbon fiber-loaded material (XT-CF20), are measured for frequencies within the range of 1 MHz to 18 GHz. These permittivity measurements demonstrated a strong anisotropy, indicating that the electromagnetic properties of the CF20 material depend on the infill method used to print. The importance of understanding the anisotropy for microwave device design is demonstrated via a dielectric-loaded cavity resonator application.


Peec-Based On-Chip Pdn Impedance Modeling Using Layered Green's Function, Chaofeng Li, Biyao Zhao, Bo Pu, Xu Wang, Donghyun Kim, Jun Fan Jan 2022

Peec-Based On-Chip Pdn Impedance Modeling Using Layered Green's Function, Chaofeng Li, Biyao Zhao, Bo Pu, Xu Wang, Donghyun Kim, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents an impedance model of on-chip power distribution network (PDN), which is an efficient criterion for estimating simultaneous switching noises (SSNs) on 3-D integrated circuit (IC). The impedance of on-chip PDN, including the effect of silicon substrate, is accurately modeled based on partial element equivalent circuit (PEEC) and layered Green's function (LGF). The equivalent circuit model of PDN is extracted based on the physical dimensions and electrical material characteristic of PDN at first. And then the LGF is used to consider the effect of silicon substrate for improving the accuracy of on-chip PDN impedance model. The effectiveness of …


A Fast Cascading Method For Predicting The Coupling From External Plane Waves To Pcbs, Shengxuan Xia, James Hunter, Aaron Harmon, Mohamed Z.M. Hamdalla, Ahmed M. Hassan, Chulsoon Hwang, Victor Khilkevich, Daryl G. Beetner Jan 2022

A Fast Cascading Method For Predicting The Coupling From External Plane Waves To Pcbs, Shengxuan Xia, James Hunter, Aaron Harmon, Mohamed Z.M. Hamdalla, Ahmed M. Hassan, Chulsoon Hwang, Victor Khilkevich, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

The radio frequency (RF) coupling to electronic devices impacts their EMC performance. The functionalities of a working electronic device may be disrupted when the electromagnetic (EM) coupling reaches a certain level. Studies of the EM coupling to printed circuit boards (PCBs) are therefore essential for RF susceptibility and EMC purposes. For decades, researchers focused on the analytical modeling of EM coupling to transmission lines. However, when it comes to more realistic PCBs the analysis usually still relies heavily on full-wave simulations because of the complexity of the structures and the lack of analytical solutions. Using a traditional full-wave modeling approach, …


A Practical Simulation Flow For Singing Capacitor Based Acoustic Noise Analysis, Xin Yan, Songping Wu, Mingfeng Xue, Chi Kin Benjamin Leung, Daryl G. Beetner, Jianmin Zhang Jan 2022

A Practical Simulation Flow For Singing Capacitor Based Acoustic Noise Analysis, Xin Yan, Songping Wu, Mingfeng Xue, Chi Kin Benjamin Leung, Daryl G. Beetner, Jianmin Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

Multilayer ceramic capacitors (MLCCs) are widely used in modern electronics. Due to the piezoelectric effect of the ceramic material, however, MLCCs subjected to electrical noise may vibrate and generate acoustic noise, as 'singing'. Acoustic noise can be annoying for users, especially within mobile devices, so it becomes important to perform acoustic noise analysis before a product is released. In this paper, a practical simulation flow for singing capacitor based acoustic noise is presented. The simulation flow and analysis method are developed on Ansys Sherlock and Mechanical. In Ansys Sherlock, local library and Approved Vendor List (AVL) files were used to …


Optimizing The Placement Of Non-Functional Pads On Signal Vias Using Multiple Reflection Analysis, Muqi Ouyang, Kevin Cai, Chaofeng Li, Anna Gao, Felen Fu, Hannah Bian, Bidyut Sen, Donghyun Kim Jan 2022

Optimizing The Placement Of Non-Functional Pads On Signal Vias Using Multiple Reflection Analysis, Muqi Ouyang, Kevin Cai, Chaofeng Li, Anna Gao, Felen Fu, Hannah Bian, Bidyut Sen, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, the effects of using non-functional pads to optimize the performance of high-speed signal vias are investigated based on multiple reflection analysis. The non-functional pads on signal vias introduce more capacitive coupling and are possible to improve the response of the via structure if the original via has relatively larger impedance compared to the system reference impedance. The effectiveness of the non-functional pad optimization is validated through a numerical example, and the eye diagram of the via structure without and with non-functional pads are compared. The eye opening becomes 5.4 times larger after the via optimization using non-functional …