Engineering Commons^™

Novel Time Domain Integral Equation Method Hybridized With The Macromodels Of Circuits, Huan Huan Zhang, He Ming Yao, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This work presents a novel transient field-circuit simulation method based on the time-domain integral equation (TDIE) and circuit macromodels. The traditional field-circuit simulation method constructs the Kirchoff's equations for lumped circuits with SPICE models, but they cannot handle problems with unknown circuit structures. The proposed method creates parametric macromodels to represent the port constitutive relations of the unknown circuits. Then the obtained macromodel is coupled with TDIE to enable the transient field-circuit cosimulation. Numerical examples are given to demonstrate the validity of the proposed method. The proposed method is targeted to solve unknown I/O modeling issues in general signal integrity …

Broadband High Gain Siw Ring Slot Antenna, Zhi Shen, Kirti Dhwaj, Hanseung Lee, Tatsuo Itoh, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The slot antenna backed by the substrate integrated waveguide (SIW) cavity usually demonstrates very narrow bandwidth. In this paper, we extend the interpretation to our original dual mode SIW ring slot antenna so that a broadband radiation property based on the TE102 mode is unveiled for the first time. Through the experimental verification, over 12% bandwidth is conveniently achieved. The realized gain reaches over 7 dB. Its broadband working principle is studied in details. Simulated and measured data are both presented to verify the proposed ideas.

Dgtd Analysis Of Electromagnetic Scattering From Penetrable Conductive Objects With Ibc, Ping Li, Yifei Shi, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

To avoid straightforward volumetric discretization, a discontinuous Galerkin time-domain (DGTD) method integrated with the impedance boundary condition (IBC) is presented in this paper to analyze the scattering from objects with finite conductivity. Two situations are considered. 1) The skin depth is smaller than the thickness of the conductive volume. 2) The skin depth is larger than the thickness of a thin conductive sheet. For the first situation, a surface impedance boundary condition (SIBC) is employed, wherein the surface impedance usually exhibits a complex relation with the frequency. To incorporate the SIBC into DGTD, the surface impedance is first approximated by …

Manipulating Electromagnetic Local Density Of States By Graphene Plasmonics, Yongpin P. Chen, Wei E.I. Sha, Li (Lijun) Jun Jiang, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic local density of states (ELDOS) counts the number of electromagnetic modes at a spatial point where a particle (atom, molecule, and quantum dot) spontaneously emits electromagnetic waves. ELDOS can be interpreted as a density of vacuum fluctuations of electromagnetic fields. Moreover, ELDOS is essential to control spontaneous decay rate (SDR) of particles; and thus plays a critical role in modern optical and quantum devices. Having a great degree of freedom to tune permittivity, graphene is an emerging building block to manipulate the ELDOS. In this work, we study SDR of a particle near a metallic split-ring resonator, which is …

Capillary Wall Coupled Whispering Gallery Mode Microresonator, Hai Xiao, Wang Hanzheng

Electrical and Computer Engineering Faculty Research & Creative Works

A microresonator structure comprises a waveguide and a microsphere. The waveguide is of elongated cylindrical shape and includes a first section of optical transmission material and a cavity section axially aligned with the first section. The cavity section includes a first cavity and a second cavity. The first cavity is adjacent to the first section and includes a first sidewall of optical transmission material with an inner surface that tapers inward to an apex positioned adjacent to the first section. The second cavity is positioned adjacent to the first cavity of hollow cylindrical shape and includes a circumferential second sidewall …

Real-Time Supervised Detection Of Pink Areas In Dermoscopic Images Of Melanoma: Importance Of Color Shades, Texture And Location, Ravneet Kaur, P. P. Albano, Justin G. Cole, Jason R. Hagerty, Robert W. Leander, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

Background/Purpose: Early detection of malignant melanoma is an important public health challenge. In the USA, dermatologists are seeing more melanomas at an early stage, before classic melanoma features have become apparent. Pink color is a feature of these early melanomas. If rapid and accurate automatic detection of pink color in these melanomas could be accomplished, there could be significant public health benefits.

Methods: Detection of three shades of pink (light pink, dark pink, and orange pink) was accomplished using color analysis techniques in five color planes (red, green, blue, hue, and saturation). Color shade analysis was performed using a logistic …

Hierarchical Equivalent Source Algorithm Based On Relaxed Spherical Equivalence Surface, Xin Fu, Li (Lijun) Jun Jiang, Hong Tat Ewe

Electrical and Computer Engineering Faculty Research & Creative Works

A new hierarchical algorithm based on surface equivalence principle is proposed in this work. The equivalent sources residing on relaxed spherical equivalence surfaces are computed by closed-form integral operators rather than numerical approximations. Consequently, a hierarchical algorithm based on oct-tree is straightforward to implement. Numerical examples validate the accuracy and capability of the proposed algorithm.

A Supercell Based Dual Beam Dielectric Grating Antenna For 60 Ghz Application, Zi Long Ma, Chi Hou Chan, Kung Bo Ng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A dual-beam dielectric grating antenna based on the supercell (SC) concept is presented in this paper. Theoretical analysis shows that with the perturbations of different unit cells (UC), two space harmonic modes (m = -1 and m = -2) are excited (above the air line) in the dispersion diagram of the supercell in a certain frequency range. This phenomenon leads to the generation of two radiation beams in the far-field region. At the operating frequency where the phase constants β-1 =β in symmetric directions. In addition, a symmetric SC is proposed and carefully designed to achieve equal performance (beam width …

Calculating The Scattered Fields From The Fock Currents Of The 3-D Convex Scatterers By The Incremental Length Diffraction Technique, Yu Mao Wu, Weng Cho Chew, Tie Jun Cui, Ya Qiu Jin, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we consider the accuracy improvement of the high frequency scattered fields from the 3-D convex scatterers with the aid of the Fock current and the incremental length diffraction coefficient (ILDC) technique. To efficiently calculate the Fock currents, we adopt the numerical contour deformation method. Then, by using the Fock currents and the ILDC technique, high frequency scattered fields are clearly formulated. Compared to the PO scattered fields from the 3-D convex sphere, numerical results demonstrate significant accuracy enhancement of the scattered field via the Fock current.

Electromagnetic Characterization For Graphene By The Peec Method, Ying S. Cao, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The electromagnetic (EM) features of graphene are characterized by the partial element equivalent circuit (PEEC) model for the first time with an impedance boundary condition. By incorporating the impedance boundary condition into the PEEC model, a novel surface conductivity circuit is proposed for graphene. Furthermore, the definition of the absorption cross section (σabs) and the scattering cross section (σsca) are revisited to make them feasible for PEEC analysis. The application of the impedance boundary condition significantly alleviates the memory consumption and the CPU time. To validate the proposed algorithm, numerical examples are presented and compared with existing references.

Modeling Of Magnetized Graphene From Microwave To Thz Range By Dgtd With A Scalar Rbc And An Ade, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a discontinuous Galerkin timedomain (DGTD) method for the transient analysis of magnetized graphene from the microwave to terahertz (THz) frequencies. By considering the atom thick graphene layer as an infinitely thin conductive sheet with finite surface conductivity, a frequency-dependent anisotropic resistive boundary condition (RBC) is obtained. Based on this RBC, the direct volumetric discretization of graphene layer is avoided. Instead of directly deriving the numerical flux for DGTD considering the presence of this anisotropic and dispersive RBC, an auxiliary surface polarization current governed by a first-order time-dependent partial differential equation (PDE) is introduced over the graphene with …

Fast Data Pattern Based Electromagnetic Interference Evaluation For Ic Packaging, Nick K.H. Huang, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) is becoming more serious when the data rate of the digital system continues increasing. However, its modeling and analysis are very challenging. In this paper, a novel electromagnetic superposition method is developed to model the IC packaging electromagnetic emission. It employs the equivalence principle to obtain the electromagnetic field response over a broad spectrum. Then it uses the linear property of the passive parasitic system to superpose the contribution of different signals on the packaging. As a result, with certain pre-calculations, it is convenient to compute the electromagnetic emission efficiently from different signals with various data pattern …

The Fast Contour Deformation Method For Calculating The High Frequency Scattered Field From The Fock Current On The Convex Scatterer, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the Fock current from the 3-D convex cylinder is considered. By using the incremental length diffraction coefficient technique (ILDC), the resultant high frequency scattered fields are expressed in terms of the Fock current from convex scatterer. To efficiently solve the scattered fields, we propose the efficient NSDP method. Numerical examples from the convex cylinder scatterer illustrate that the proposed NSDP method for calculating the high frequency scattered fields could achieve the frequency independent computational workload and error controllable accuracy.

Distributive Radiation And Transfer Characterization Based On The Peec Method, Ying S. Cao, Li (Lijun) Jun Jiang, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Power radiation and radiated coupling among different structures represent an important area for research study. The partial element equivalent circuit method (PEEC) is a powerful technique which bridges the gap between the electromagnetic and circuit theories. In this paper, we develop a new approach for PEEC to calculate the distributive power radiation and couplings. With this approach, formulations for both the radiated power and the transferred power can be evaluated. Further, the physical meanings of the power results are interpreted according to the conservation of energy law. We use electric dipoles, magnetic dipoles and patch antennas as well as coupled …

Method Of Effective Roughness Dielectric In A Pcb: Measurement And Full-Wave Simulation Verification, Marina Koledintseva, Tracey Vincent, Antonio Ciccomancini Scogna, Scott Hinaga

Electrical and Computer Engineering Faculty Research & Creative Works

Surface roughness topography of printed circuit boards (PCBs) needs to be included in signal integrity simulations in order to accurately predict the insertion loss of the structure and its delay time. An effective roughness dielectric (ERD) model can be used to substitute an inhomogeneous interface between copper foil and laminate dielectric in a PCB. Herein, this approach is tested for verification using 3-D full-wave numerical simulations. These ERD layers with the appropriate complex permittivity are included in the modeling of strip line examples. The parameters of an ambient laminate dielectric refined from conductor roughness in the strip line are determined …

Uncertainty Quantification For Electromagnetic Systems Using Asgc And Dgtd Method, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an adaptive hierarchical sparse grid collocation (ASGC) method combined with the discontinuous Galerkin time-domain method is leveraged to quantify the impacts of random parameters on the electromagnetics systems. The ASGC method approximates the stochastic observables of interest using interpolation functions over a set of collocation points determined by the Smolyak's algorithm integrated with an adaptive strategy. Instead of resorting to a full-tensor product sense, the Smolyak's algorithm constructs the collocation points in a hierarchical scheme with the interpolation level. Enhanced by an adaptive strategy, the Smolyak's algorithm will sample more points along important dimensions with sharp variations …

Passive Equalizer And High-Speed Digital Signal Transmission System Using The Same, Eak Hwan Song, Young Kun Kwon, Won Seob Kim, Hark Byeong Park, Hyun Sik Yun, Eun Seok Hong, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Disclosed herein are a passive equalizer and a high-speed digital signal transmission system, including first and second impedances connected in series to a first transfer line, third and fourth impedances connected in series to a second transfer line, a first inductor connected in parallel between the first impedance and the second impedance, a second inductor connected in parallel between the third impedance and the fourth impedance, and a resistor connected in series between the first inductor and the second inductor.

Transmission-Line Equivalent And Microstrip Structure For Planar Möbius Loop Resonator, Kirti Dhwaj, Hanseuyng Lee, Lijun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

A transmission line model for planar Möbius loop resonator is presented. Theoretical background for the Möbius loop is developed by treating it as a ring resonator. Even-Odd mode analysis is used to account for the dual mode nature of the resonator. Also, the presence of two transmission zeroes is explained using the proposed model. The transmission line model is then used to implement a simple microstrip version of the Möbius loop resonator. A single resonator is then used to implement a dual-mode bandpass filter. Simulation and test results of the structure are presented.

A Resistive Boundary Condition Enhanced Dgtd Scheme For The Transient Analysis Of Graphene, Ping Li, Li (Lijun) Jun Jiang, Hakan Baʇci

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the electromagnetic (EM) features of graphene are characterized by a discontinuous Galerkin time-domain (DGTD) algorithm with a resistive boundary condition (RBC). The atomically thick graphene is equivalently modeled using an RBC by regarding the graphene as an infinitesimally thin conductive sheet. To incorporate RBC into the DGTD analysis, the surface conductivity of the graphene composed of contributions from both intraband and interband terms is first approximated by rational basis functions using the fast-relaxation vector-fitting (FRVF) method in the Laplace domain. Next, through the inverse Laplace transform, the corresponding time-domain matrix equations in integral can be obtained. Finally, …

Real Time Mission Planning, Emad William Saad, Stefan Richard Bieniawski, Paul Edward Riley Pigg, John Lyle Vian, Paul Michael Robinette, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The different advantageous embodiments provide a system comprising a number of computers, a graphical user interface, first program code stored on the computer, and second program code stored on the computer. The graphical user interface is executed by a computer in the number of computers. The computer is configured to run the first program code to define a mission using a number of mission elements. The computer is configured to run the second program code to generate instructions for a number of assets to execute the mission and monitor the number of assets during execution of the mission.

Preface, Gennady Fridman, Jeremy Levesley, Ivan Tyukin, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

In August 2014 a conference on “Model reduction across disciplines” was held in Leicester, UK. As a scientific field, model reduction is an important part of mathematical modelling and data analysis with very wide areas of applications. The main scientific goal of the conference was to facilitate interdisciplinary discussion of model reduction and coarse-graining methodologies in order to reveal their general mathematical nature. This time, however, the conference had an additional personal and more profound mission – it was dedicated to the 60th birthday of Professor Alexander Gorban (albeit with some delay) whose fantastic achievements in applying model reduction techniques …

Work-In-Progress: Statistics Components In A Circuits Laboratory For Ece Sophomores, Steve Eugene Watkins, Theresa M. Swift, Amardeep Kaur

Electrical and Computer Engineering Faculty Research & Creative Works

Statistics concepts are required for undergraduate curricula in electrical engineering and computer engineering (ECE). Accreditation guidelines specify that such instruction must include “applications appropriate to the program name” [ABET Criteria for Accrediting Engineering Programs, 2014-2015]. Curricula content in probability and statistics are commonly done in a stand-alone course, but additional exposure within engineering-content courses can provide great value. Many basic concepts can be introduced before the comprehensive stand-alone course. A good ECE context is an electrical circuits laboratory in which students need to understand electrical component tolerances and related design issues. Statistics-related assignments in a required, sophomore-level laboratory course are …

Methods And Systems For Biclustering Algorithm, Donald C. Wunsch, Rui Xu, Sejun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Methods and systems for improved unsupervised learning are described. The unsupervised learning can consist of biclustering a data set, e.g., by biclustering subsets of the entire data set. In an example, the biclustering does not include feeding know and proven results into the biclustering methodology or system. A hierarchical approach can be used that feeds proven clusters back into the biclustering methodology or system as the input. Data that does not cluster may be discarded. Thus, a very large unknown data set can be acted on to learn about the data. The system is also amenable to parallelization.

Physical Interpretation Of Radiation And Transfer Characterization Based On The Peec Method, Ying S. Cao, Li (Lijun) Jun Jiang, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The characterization of power radiation and coupling has been an important research subject. The partial element equivalent circuit method (PEEC) is a powerful tool in bridging the electromagnetic modeling together with a circuit solver. Even though PEEC was a convenient tool for many quasi-static applications, in this paper, we propose a new approach for PEEC to calculate the radiated and coupled power from the distributive point of view. Formulations for both radiated and transferred powers are proposed based on a full wave PEEC model. Distributive power can be evaluated with negligible additional computational cost in PEEC implementations. The physical meaning …

Full-Wave Simulation Of An Imbalanced Differential Microstrip Line With Conductor Surface Roughness, Marina Koledintseva, Tracey Vincent, Sergiu Radu

Electrical and Computer Engineering Faculty Research & Creative Works

This study investigates the full-wave numerical electromagnetic analysis of edge-coupled differential microstrip lines on a printed circuit board (PCB), when conductor surface roughness is taken into account. Mixed mode parameters of such lines are analyzed. The imbalance in the electric lengths of the traces causes the appearance of common-mode currents, as well as mode conversion: differential mode (DM) to common-mode (CM) and CM to DM. The presence of the solder mask on top of the PCB with microstrip traces is also taken into account. The differential lines modeled in this work are of three types: straight, bent, and curved. The …

Facial Structure Analysis Separates Autism Spectrum Disorders Into Meaningful Clinical Subgroups, Tayo Obafemi-Ajayi, Judith H. Miles, T. Nicole Takahashi, Wenchuan Qi, Kristina Aldridge, Minqi Zhang, Shi Qing Xin, Ying He, Ye Duan

Electrical and Computer Engineering Faculty Research & Creative Works

Varied cluster analysis were applied to facial surface measurements from 62 prepubertal boys with essential autism to determine whether facial morphology constitutes viable biomarker for delineation of discrete Autism Spectrum Disorders (ASD) subgroups. Earlier study indicated utility of facial morphology for autism subgrouping (Aldridge et al. in Mol Autism 2(1):15, 2011). Geodesic distances between standardized facial landmarks were measured from three-dimensional stereo-photogrammetric images. Subjects were evaluated for autism-related symptoms, neurologic, cognitive, familial, and phenotypic variants. The most compact cluster is clinically characterized by severe ASD, significant cognitive impairment and language regression. This verifies utility of facially-based ASD subtypes and validates …

The Contour Deformation Method For Calculating The High-Frequency Scattered Field By The Fock Current On The Surface Of The 3-D Convex Cylinder, Yu Mao Wu, Li (Lijun) Jun Jiang, Weng Cho Chew, Ya Qiu Jin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the high-frequency diffracted waves like the creeping waves are comprehensively analyzed by the Fock currents. On invoking the contour deformation method, the highly oscillatory Fock currents are efficiently calculated. Furthermore, the workload for the calculation of Fock currents is frequency-independent. To capture the high-frequency wave physics phenomenon, the Fock current is separated into the classical physical optics (PO) current and the nonuniform (NU)-Fock current along the shadow boundary and in the deep shadow region. To calculate the highly oscillatory scattered wave fields from the Fock current, quadratic approximations of the phase functions in the integrand are adopted. …

Wavelength-Selective Switch With Direct Few Mode Fiber Integration, D. M. Marom, J. Dunayevsky, D. Sinefeld, M. Blau, Roland Ryf, Nicolas K. Fontaine, M. Montoliu, S. Randel, C. Liu, B. Ercan, Mina Esmaeelpour, For Full List Of Authors, See Publisher's Website.

Electrical and Computer Engineering Faculty Research & Creative Works

The first realization of a wavelength-selective switch (WSS) with direct integration of few mode fibers (FMF) is fully described. The freespace optics FMF-WSS dynamically steers spectral information-bearing beams containing three spatial modes from an input port to one of nine output ports using a phase spatial light modulator. Sources of mode dependent losses (MDL) are identified, analytically analyzed and experimentally confirmed on account of different modal sensitivities to fiber coupling in imperfect imaging and at spectral channel edges due to mode clipping. These performance impacting effects can be reduced by adhering to provided design guidelines, which scale in support of …

The Fast Solver For Calculating The High Frequency Scattered Field From The Fock Current On The Surface Of The 3-D Convex Scatterer, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we first consider the Fock current from the 3-D convex cylinder. Next, on invoking the incremental length diffraction technique (ILDC), the resultant high frequency scattered fields are expressed in terms of the Fock current. We propose the NSDP method to calculate these scattered fields. Numerical examples illustrate that the proposed NSDP method for calculating the high frequency scattered fields could achieve the frequency independent computational workload and error controllable accuracy.

Accuracy Enhancement Of The Equivalence Principle Algorithm Based On The Meshless Spherical Surface, Xin Fu, Lijun Jiang, Zuhui Ma

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional equivalence principle algorithm (EPA) employs cubical boxes to support equivalence sources. However, it introduces strong discontinuities. In this work, a spherical surface is employed as the equivalence surface in EPA to avoid singularities from non-smooth surfaces. Further to achieve high order accuracy, meshless samples are used for the integrals on the spherical surface to avoid the equivalence surface mesh discretization. Theoretically the accuracy of EPA can be significantly improved, which was further benchmarked though numerical examples. Various meshless schemes are also discussed to achieve the optimal solution based on the spherical equivalence surface.