Engineering Commons^™

Inter-Cross De-Modulated Refractive Index And Temperature Sensor By An Etched Multi-Core Fiber Of A Mzi Structure, Farhan Mumtaz, Yutang Dai, Muhammad Aqueel Ashraf

Electrical and Computer Engineering Faculty Research & Creative Works

We present a relative sensitivity of in-fiber inter-cross demodulation of a Mach-Zehnder interferometer (MZI) based on an etched multi-core fiber (eMCF). The sensor can measure the external refractive index (RI) and temperature with a large fringe visibility of 15 dB. It is tuned using a simple technique of slow chemical etching. When the outer cores of MCF will be exposed to the surrounding, a large difference of relative effective RI is observed, which enhances the sensitivity of the sensor. The sensor's wavelength and intensity responses have displayed that it can function with three different inter-cross-demodulation phenomena. A superior RI sensitivity …

Welcome Message From The Tpc Chairs, Ming Yu, Lijun Jiang, Alex Man Hon Wong, Shao Yong Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Applying Power Dividers To Decoupling Of Mimo Antennas With Wideband, Dual-Band Or Adjacent-Band Operations, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel decoupling method of applying power dividers to isolation enhancement of multiple-input multiple-output antennas with wideband, dual-band, or adjacent-band operations. The decoupling structure consists of the power dividers, transmission lines, and reactive components. Three benchmarks are used to elaborate on the design procedure and demonstrate the advantages of the proposed method. Results show that this method offers good impedance matching and high port isolation at the designated frequencies.

An Efficient 3-D Stochastic Hie-Fdtd Algorithm For Investigation Of Statistical Variation In Electromagnetic Field, Kaikun Niu, Zhixiang Huang, Xingang Ren, Ke Xu, Minquan Li, Xianliang Wu, Ping Li, Lijun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

We propose a stochastic hybrid implicit-explicit finite-difference time-domain method (S-HIE-FDTD) to compute the mean and variance of the electromagnetic (EM) fields using a single simulation, given those of the conductivity and permittivity in the computation domain. The mean and variance field update equations underlying the proposed method are derived from the field update equations of the 'traditional' deterministic HIE-FDTD. The Courant-Friedrichs-Lewy condition of the S-HIE-FDTD depends on the spatial discretization sizes only in two dimensions; therefore, for computation domains with fine geometric features only in the remaining dimension, it uses a time step size that is larger than that of …

Machine-Learning-Based Hybrid Method For The Multilevel Fast Multipole Algorithm, Jia Jing Sun, Sheng Sun, Yongpin P. Chen, Lijun Jiang, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, a hybrid translation computation method for the multilevel fast multipole algorithm (MLFMA) is proposed based on machine learning. The hybrid method combines both generalized regression neural network (GRNN) and artificial neural network (ANN) to replace the traditional translation procedure during the solving process of the MLFMA. Based on the data corresponding to every one of the interaction list boxes at each level, the hybrid neural network is trained. Comparing with the previous machine learning method in this field, the proposed model is more general, and with lower complexity since it inherits the accuracy of the GRNN as …

Coexistence Of Pseudospin- And Valley-Hall-Like Edge States In A Photonic Crystal With C3v Symmetry, Menglin L.N. Chen, Li Jun Jiang, Zhihao Lan, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

We demonstrate the coexistence of pseudospin- and valley-Hall-like edge states in a photonic crystal with C3v symmetry, which is composed of three interlacing triangular sublattices with the same lattice constants. By tuning the geometry of the sublattices, three complete photonic band gaps with nontrivial topology can be created, one of which is due to the band inversion associated with the pseudospin degree of freedom at the Γ point and the other two due to the gapping out of Dirac cones associated with the valley degree of freedom at the K,K′ points. The system can support triband pseudospin- and valley-momentum locking …

Thermo-Coupled Temperature Sensors By Seven-Core Mcf Structures, Farhan Mumtaz, Yutang Dai, Wenbin Hu, Muhammad Aqueel Ashraf, Shu Cheng, Pu Cheng

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we present an enhanced sensitivity of temperature sensors based on thermo-coupled Multicore Fiber (MCF) structures. The sensors are all fabricated using a controlled arc power of a splicing device. Two different principles of a Mach-Zehnder interferometer (MZI) and Michelson interferometer (MI) have been observed experimentally. The MZI and MI structures exhibit temperature sensitivity as 136.67 pm/°C and 70.61 pm/°C, respectively, and found insensitive to the refractive index (RI). Also, its RI response can readily resolve the issues of cross-sensitivity.

Second-Harmonic Generation Of Structured Light By Transition-Metal Dichalcogenide Metasurfaces, Ling Ling Meng, Xiaoyan Y.Z. Xiong, Tian Xia, Qin S. Liu, Li (Lijun) Jun Jiang, Wei E.I. Sha, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

Structured light characterized by spatially inhomogeneous optical fields found rich applications in optical communication, sensing, microscopy, manipulation, and quantum information. While generation of structured light has been extensively studied in linear optics, the nonlinear optical process, particularly in two-dimensional (2D) materials, is an emerging alternative for generating structured light at shorter wavelengths. In this work, we theoretically demonstrate that radially and azimuthally polarized beams and vortex beams carrying orbital angular momentum could be generated at second-harmonic frequencies by using 2D material-based metasurfaces comprising the same transition-metal dichalcogenide meta-atoms. Manipulation of translations and orientations of anisotropically nonlinear meta-atoms exhibiting a threefold …

Ebg Common-Mode 20-Ghz Microstrip And Stripline Filters: Sensitivity To Design Parameters, Marina Y. Koledintseva, Sergiu Radu, Joseph Nuebel

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, design and characteristics of 20-GHz electromagnetic bandgap (EBG) common-mode (CM) filters for microstrip (MS) and strip line (SL) differential pairs are considered. CM filter notch (resonance) frequency, depth, and width at the-15 dB level are calculated from the mixed-mode S-parameters. The agreement between the measured and modeled S-parameters of the baseline structures validates the models and allows for further numerical experiments. The systematic analysis of the trends for both MS and SL filter characteristics as functions of various geometrical and material design parameters is presented. Sensitivity to various technological features (conductor surface roughness, trapezoid shape of the …

A Novel Dual-Band Decoupling Technique, Min Li, Jamal Muhammad Yasir, Kwan Lawrence Yeung, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a novel dual-band decoupling network (DN) to increase the isolation between two antennas. It is composed of two dual-band Wilkinson power dividers, four additional transmission lines (TLs), and two reactive components. The decoupling formulas are derived from systematic design procedures. Hence, the design parameters of the power divider, lengths of TLs, and reactance of reactive components can be precisely determined to realize high port isolation. Two benchmarks of the two-element symmetric and asymmetric monopole arrays are used to elaborate the design procedure and demonstrate the advantages of proposed DN. Results show that the proposed DN can offer …

A Novel Subdomain 2d/Q-2d Finite Element Method For Power/Ground Plate-Pair Analysis, Ping Li, Li (Lijun) Jun Jiang, Min Tang, Yao Jiang Zhang, Shuai Xu, Hakan Bagc

Electrical and Computer Engineering Faculty Research & Creative Works

Upon excitation by a surface magnetic current, a power/ground plate-pair supports only TMz modes. This means that the magnetic field has only azimuthal components permitting a simple but effective domain decomposition method (DDM) to be used. In the proximity of an antipad, field interactions are rigorously modeled by a quasi-two-dimensional (Q-2D) finite element method (FEM) making use of three-dimensional (3D) triangular prism mesh elements. Since high-order TMz modes are confined in the close proximity of the antipad, field interactions in the region away from the antipad only involve the fundamental mode and are rigorously modeled by a 2D FEM. This …

An Explainable And Statistically Validated Ensemble Clustering Model Applied To The Identification Of Traumatic Brain Injury Subgroups, Dacosta Yeboah, Louis Steinmeister, Daniel B. Hier, Bassam Hadi, Donald C. Wunsch, Gayla R. Olbricht, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

We present a framework for an explainable and statistically validated ensemble clustering model applied to Traumatic Brain Injury (TBI). The objective of our analysis is to identify patient injury severity subgroups and key phenotypes that delineate these subgroups using varied clinical and computed tomography data. Explainable and statistically-validated models are essential because a data-driven identification of subgroups is an inherently multidisciplinary undertaking. In our case, this procedure yielded six distinct patient subgroups with respect to mechanism of injury, severity of presentation, anatomy, psychometric, and functional outcome. This framework for ensemble cluster analysis fully integrates statistical methods at several stages of …

Numerical Solution Of Strongly Guided Modes Propagating In Sapphire Crystal Fibers (Α-Al2o3) For Uv, Vis/Ir Wave-Guiding, Farhan Mumtaz, Muhammad Aqueel Ashraf, Yutang Dai, Wenbin Hu

Electrical and Computer Engineering Faculty Research & Creative Works

A numerical solution, using the general formulation of the transcendental equation and eigenmode values, is proposed to demonstrate number of strongly guided modes propagating in sapphire crystal fibers (SCF). The SCF is considered to have hexagonal geometry of a single crystal and multimode step-index profile. Several distinguished characteristics are naturally embedded in SCF compared to other ordinary optical fibers. The eigenmodes of the SCF are numerically determined and are a combination of transverse electric, transverse magnetic, and hybrid modes. The numerical solution for wave-guiding in ultra-violet (UV), visible infrared (VIS/IR) spectrum, is investigated by the number of modal propagations under …

Evaluation Of Standard And Semantically-Augmented Distance Metrics For Neurology Patients, Daniel B. Hier, Jonathan Kopel, Steven U. Brint, Donald C. Wunsch, Gayla R. Olbricht, Sima Azizi, Blaine Allen

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Patient distances can be calculated based on signs and symptoms derived from an ontological hierarchy. There is controversy as to whether patient distance metrics that consider the semantic similarity between concepts can outperform standard patient distance metrics that are agnostic to concept similarity. The choice of distance metric can dominate the performance of classification or clustering algorithms. Our objective was to determine if semantically augmented distance metrics would outperform standard metrics on machine learning tasks.

Methods: We converted the neurological findings from 382 published neurology cases into sets of concepts with corresponding machine-readable codes. We calculated patient distances by …

Mismatch In Ebg Common-Mode Filters Implemented On Pcbs, Marina Y. Koledintseva, Sergiu Radu, Joseph Nuebel

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, impedance mismatch effects on the characteristics of common-mode (CM) electromagnetic bandgap (EBG) filters are studied using three-dimensional (3-D) full-wave numerical simulations. The CM EBG filters considered herein are designed using standard printed circuit board technology and contain either microstrip (MS) differential pairs running above the EBG plane, or strip line (SL) differential pairs running on one of the layers next to the EBG plane. First, the terminations are fixed at 50 Ω, and the effects of the differential line impedance variations on the EBG filter parameters are studied. Overall, the considered variations in the widths of the …

A Novel Data-Driven Analysis Method For Electromagnetic Radiations Based On Dynamic Mode Decomposition, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic radiations in complex electronic systems such as cell phones and computers are complex spatial oral correlations signals. Decomposing the electromagnetic radiation measured in the spatial oral domain is useful to gain physical insights into the process that generates radio frequency interference and the radiated spurious emission. In this article, a novel data-driven characterization method is proposed to analyze the electromagnetic radiations of both linear and nonlinear circuits. It employs the dynamic mode decomposition to simultaneously extract the temporal patterns and their corresponding dynamic modes. The temporal patterns show high-order harmonics generated by the nonlinearity. Then, these spatial oral coherent …

Transceivers As A Resource: Scheduling Time And Bandwidth In Software-Defined Radio, Nathan D. Price, Maciej Jan Zawodniok, Ivan G. Guardiola

Electrical and Computer Engineering Faculty Research & Creative Works

In the future, software-defined radio may enable a mobile device to support multiple wireless protocols implemented as software applications. These applications, often referred to as waveform applications, could be added, updated, or removed from a software-radio device to meet changing demands. Current software-defined radio solutions grant an active waveform exclusive ownership of a specific transceiver or analog front-end. Since a wireless device has a limited number of front-ends, this approach puts a hard constraint on the number of concurrent waveform applications a device can support. A growing trend in software-defined radio research is to virtualize front-ends to allow sharing and …

A Novel Self-Restrained Decoupling Technique For Two Antennas, Min Li, Muhammad Yasir Jamal, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel self-restrained (SR) decoupling technique (DT) is presented to increase the isolation between two antennas. The 'self-restrained' feature means that the decoupling structure is only attached to the individual antenna itself without demanding any connection to other being coupled ones. The design parameters of the resultant decoupling structure can be precisely derived to achieve high isolations. A two-element monopole array is employed as a benchmark. Results show that good matching and high isolation are achieved simultaneously.

A Novel Planar Dual Cp Mimo Antenna With Polarization Diversity And High Isolation, Muhammad Yasir Jamal, Min Li, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a low cost planar two-port circularly polarized MIMO patch antenna with the polarization diversity is presented. Three grounded stubs and a mirrored F defected ground slot are used to achieve simultaneous matching and isolation between the two patch and offset feeding for circular polarization. The proposed antenna covering 2.5-2.55 GHz is fabricated and measured. Its measured performance show that \mathbf{\mathrm{S}_{11} < -10\ \mathrm{dB},\ \mathrm{S}_{12} < -20\ \mathrm{dB}} and axial ratio \mathbf{< 3\mathrm{dB}} for the whole band. Its radiation patterns and gain are also measured and an agreement with the simulation result has been achieved.

A Novel Wideband Decoupling Network For Two Antennas, Min Li, Muhammad Yasir Jamal, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel wideband decoupling network (DN) is presented, which consists of two 2-way Wilkinson power dividers (WPDs), three transmission lines, and two reactive components. Rigorous design formulas are presented along with systematic design procedures. The transmission-line lengths and component reactances are precisely calculated to achieve high antenna isolation. Measurement results show that a very wide isolation bandwidth of 23.7% can be achieved after using the proposed DN.

Adaptive Interference Mitigation Using Frequency-Selective Limiters Over Gps Band For Automotive Applications, Mahima Shukla, Marina Y. Koledintseva, Michael Geiler, Scott Gillette, Michael Hunnewell, Anton L. Geiler

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we address the challenges associated with the necessity to protect Global Positioning system (GPS) receivers from various types of electromagnetic interference (EMI) generated by internal or external sources. We have developed a compact, lightweight, and passive frequency selective limiter (FSL) technology that automatically and adaptively protects vulnerable input circuits of a GPS receiver from unwanted emissions and prevents a GPS receiver from going into saturation. This technology is based on using magnetostatic surface waves in a magnetically biased ferrite film. The nonlinear processes in ferrite films enable discrimination of signals based on their power levels. In these …

A Design Of Taper-Like Etched Multicore Fiber Refractive Index-Insensitive A Temperature Highly Sensitive Mach-Zehnder Interferometer, Farhan Mumtaz, Pu Cheng, Chi Li, Shu Cheng, Cheng Du, Minghong Yang, Yutang Dai, Wenbin Hu

Electrical and Computer Engineering Faculty Research & Creative Works

We propose and demonstrate Mach-Zehnder interferometer (MZI), which is the refractive index (RI) insensitive and temperature highly sensitive based on etched multi-core fiber (MCF) structure. The MCF and Fiber Bragg Grating (FBG) are used as hybrid sensing elements. The fabrication of the interferometer is provided a new taper-like structure by etching the MCF to further expose the side cores to the surroundings. The interferometer has produced a sensitivity of 103.2pm/°C within the ambient temperature up-to 70°C. Moreover, the superior temperature sensitivity is 89.19pm/°C, 66.64pm/°C, 56.42pm/°C in the range of 24°C to 130°C, and RI-insensitive in the range of 1.34 to …

Enhanced Deep Learning Approach Based On The Deep Convolutional Encoder-Decoder Architecture For Electromagnetic Inverse Scattering Problems, He Ming Yao, Lijun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

This letter proposes a novel deep learning (DL) approach to resolve the electromagnetic inverse scattering (EMIS) problems. The conventional approaches of resolving EMIS problems encounter assorted difficulties, such as high contrast, high computational cost, inevitable intrinsic nonlinearity, and strong ill-posedness. To surmount these difficulties, a novel DL approach is proposed based on a novel complex-valued deep fully convolutional neural network structure. The proposed complex-valued deep learning model for solving EMIS problems composes of an encoder network and its corresponding decoder network, followed by a final pixel-wise regression layer. The complex-valued encoder network extracts feature fragments from received scattered field data, …

An Algorithm For The Evolutionary-Fuzzy Generation Of On-Line Signature Hybrid Descriptors, Marcin Zalasinski, Krzysztof Cpalka, Lukasz Laskowski, Donald C. Wunsch, Krzystof Przybyszewski

Electrical and Computer Engineering Faculty Research & Creative Works

In biometrics, methods which are able to precisely adapt to the biometric features of users are much sought after. They use various methods of artificial intelligence, in particular methods from the group of soft computing. In this paper, we focus on on-line signature verification. Such signatures are complex objects described not only by the shape but also by the dynamics of the signing process. In standard devices used for signature acquisition (with an LCD touch screen) this dynamics may include pen velocity, but sometimes other types of signals are also available, e.g. pen pressure on the screen surface (e.g. in …

Improved Classification Of Medical Data Using Meta-Best Feature Selection, Matthew Chaplin, Jacob Grubb, Thomas Clifford, Justin Bruce, Tayo Obafemi-Ajayi, John Matta

Electrical and Computer Engineering Faculty Research & Creative Works

Feature selection provides a useful method for reducing the size of large data sets while maintaining integrity, thereby improving the accuracy of neural networks and other classifiers. However, running multiple feature selection models and their accompanying classifiers can make interpreting results difficult. To this end, we present a data-driven methodology called Meta-Best that not only returns a single feature set related to a classification target, but also returns an optimal size and ranks the features by importance within the set. This proposed methodology is tested on six distinct targets from the well-known REGARDS dataset: Deceased, Self-Reported Diabetes, Light Alcohol Abuse …

A Novel Wideband Decoupling Network For Two Antennas Based On The Wilkinson Power Divider, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, a wideband decoupling network (DN) is presented based on the Wilkinson power divider (WPD). The DN is composed of 2 two-way unequal WPDs, three transmission lines (TLs), and two reactive components. Two techniques are introduced for the wideband performance: 1) by using the WPD with high output isolation, the antenna matching becomes independent of antenna decoupling. So, the decoupled antennas with the proposed DN could perform broad impedance bandwidths without using matching networks and 2) the DN is designed to minimize antennas' coupling coefficients at two frequencies, which collectively contribute to a broader decoupling bandwidth. In addition, …

One-Dimensional Sensor Learns To Sense Three-Dimensional Space, Chen Zhu, Rex E. Gerald, Yizheng Chen, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

A sensor system with ultra-high sensitivity, high resolution, rapid response time, and a high signal-to-noise ratio can produce raw data that is exceedingly rich in information, including signals that have the appearances of "noise". The "noise"feature directly correlates to measurands in orthogonal dimensions, and are simply manifestations of the off-diagonal elements of 2nd-order tensors that describe the spatial anisotropy of matter in physical structures and spaces. The use of machine learning techniques to extract useful meanings from the rich information afforded by ultra-sensitive one-dimensional sensors may offer the potential for probing mundane events for novel embedded phenomena. Inspired by our …

Channel Estimators For Full-Duplex Communication Using Orthogonal Pilot Sequences, Arul Mathi Maran Chandran, Lei Wang, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Full-duplex communication is desirable to maximize the spectral efficiency, despite the challenges it puts forth. The key challenge inhibiting the operation of radios in full-duplex mode is self-interference. In this paper, we propose a pilot-based channel estimation to estimate both self-interference and communication channels simultaneously at both ends of a full-duplex link using orthogonal sequences. The Cramer-Rao Lower Bound for estimators of both the channels was determined and compared with the half-duplex channel estimator. We performed simulations varying sequence length and channel taps and studied the performance of the estimators. We also studied the effect of synchronization between the sequences …

Dc Ir-Drop Analysis Of Multilayered Power Distribution Network By Discontinuous Galerkin Method With Thermal Effects Incorporated, Ping Li, Min Tang, Zhi Xiang Huang, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the temperature-dependent resistivity of power distribution network (PDN) interconnects, a wiser and necessary strategy is to proceed the electrical-thermal cosimulation in order to include the thermal effects caused by Joule heating. As a natural domain decomposition method (DDM), in this article, a discontinuous Galerkin (DG) method is proposed to facilitate the steady-state electrical and thermal coanalysis. With the intention to avoid solving a globally coupled steady-state matrix system equations resulted from the implicit numerical flux in DG, the block Thomas method is deployed to solve the entire domain in a subdomain-by-subdomain scheme. As a direct solver, the block …

A General And Systematic Method To Design Neutralization Lines For Isolation Enhancement In Mimo Antenna Arrays, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

A general and systematic approach is the first time proposed in this paper to design the neutralization line (NL) for isolation enhancement in multiple-input multiple-output (MIMO) antenna arrays. Each NL consists of a metal strip and a reactive component attached at its middle position. It is connected with every two antenna radiators to generate an additional coupling path against the original antenna coupling for isolation enhancement. A general network model that leads to a systematic design procedure is developed to meet the required isolation criteria. Three practical examples are presented and used to verify the proposed NL-based decoupling technique (DT). …