Digital Commons Network^™

The Derived Equivalent Circuit Model For Magnetized Anisotropic Graphene, Ying S. Cao, Ping Li, Li (Lijun) Jun Jiang, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the static magnetic field, the conductivity for graphene becomes a dispersive and anisotropic tensor, which complicates most modeling methodologies. In this communication, a novel equivalent circuit model is proposed for graphene with the magnetostatic bias based on the electric field integral equation. To characterize the anisotropic property of the biased graphene, the resistive part of the unit circuit is replaced by a resistor in series with current-controlled voltage sources (CCVSs). The CCVSs account for the off-diagonal parts of the surface conductivity tensor for the magnetized graphene. This proposed method is benchmarked with numerical examples. This communication also provides …

Record: Temporarily Randomized Encoding Of Combinational Logic For Resistance To Data Leakage From Hardware Trojan, Travis E. Schulze, Kevin Kwiat, Charles Kamhoua, Shih Chieh Chang, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Many design companies have gone fabless and rely on external fabrication facilities to produce chips due to increasing cost of semiconductor manufacturing. However, not all of these facilities can be considered trustworthy; some may inject hardware Trojans and jeopardize the security of the system. One common objective of hardware Trojans is to a establish side channel for data leakage. While extensive literature exists on various defensive measures, almost all of them focus on preventing the establishment of side channels and can be compromised if attackers gain access to the physical chip and can perform reverse engineering between multiple fabrication runs. …

Filamentary Conduction In Aloe Vera Film For Memory Application, Zhe Xi Lim, Sasidharan Sreenivasan, Yew Hoong Wong, Feng Zhao, Kuan Yew Cheong

Electrical and Computer Engineering Faculty Research & Creative Works

Aloe vera gel was extracted, formulated and deposited as thin films by a facile solution process for memory application. The memory cell features a simple structure, in which a dried Aloe vera film was sandwiched in between an Ag top and ITO bottom electrode that was deposited on a glass substrate. Digital information can be encoded and stored as different resistance states of the Aloe vera film. Experimental results reveal that bipolar resistive switching behavior of the Aloe vera film is due to electrochemical growth and dissolution of metallic filaments connecting the top and bottom electrodes. The resistive switching behavior …

An Efficient Numerical Contour Deformation Method For Calculating Electromagnetic Scattered Fields From 3-D Convex Scatterers, Yu Mao Wu, Weng Cho Chew, Ya Qiu Jin, Tie Jun Cui, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

We consider the accuracy improvement of the high frequency scattered fields from 3-D convex scatterers. The Fock currents from the convex scatterers are carefully studied. Furthermore, we propose the numerical contour deformation method to calculate the Fock currents with frequency independent workload and error controllable accuracy. Then, by adopting the Fock currents and the incremental length diffraction coefficient (ILDC) technique, the scattered fields are clearly formulated. Compared to physical optics (PO) scattered fields from 3-D convex sphere, numerical results demonstrate significant accuracy enhancement of the scattered field via the Fock current approach.

Decentralized Fault Diagnosis And Prognosis Scheme For Interconnected Nonlinear Discrete-Time Systems, Hasan Ferdowsi, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper deals with the design of a decentralized fault diagnosis and prognosis scheme for interconnected nonlinear discrete-time systems which are modelled as the interconnection of several subsystems. For each subsystem, a local fault detector (LFD) is designed based on the dynamic model of the local subsystem and the local states. Each LFD consists of an observer with an online neural network (NN)-based approximator. The online NN approximators only use local measurements as their inputs, and are always turned on and continuously learn the interconnection as well as possible fault function. A fault is detected by comparing the output of …

Vehicle Base Station, Emad William Saad, J. L. Vian, Matthew A. Vavrina, J. A. Nisbett, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

A system to load and unload material from a vehicle comprises a vehicle base station and an assembly to autonomously load and unload material from the vehicle.

No-Boundary Thinking In Bioinformatics, Jason H. Moore, Steven F. Jennings, Casey S. Greene, Lawrence E. Hunter, Andy D. Perkins, Clarlynda Williams-Devane, Donald C. Wunsch, Zhongming Zhao, Xiuzhen Huang

Electrical and Computer Engineering Faculty Research & Creative Works

The following sections are included:
Bioinformatics is a Mature Discipline
The Golden Era of Bioinformatics Has Begun
No-Boundary Thinking in Bioinformatics
References

A Collimated Surface-Wave-Excited High-Impedance Surface Leaky-Wave Antenna, Zi Long Ma, Chi Hou Chan, Kung Bo Ng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This letter presents a novel high-impedance surface (HIS)-based leaky-wave antenna excited by collimated surface wave (SW). The proposed antenna consists of two identical SW launchers (SWLs) and an HIS structure. Regarding the SWL, it is based on an offset-fed parabolic reflector. By using the substrate-integrated waveguide technique, the reflector system is integrated in the planar substrate. For the HIS, it is formed by a periodically arranged rectangular microstrip patch array. The proposed SWL can generate collimated SW with the propagation mode. With the perturbation of the HIS, the guided SW can be transformed to m = -1 space-harmonic-mode leaky wave. …

Low Frequency Behavior Of Cvd Graphene From Dc To 40 Ghz, Rong Wang, Salahuddin Raju, Mansun Chan, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic behaviour of chemical vapor deposition (CVD) graphene at low frequencies is still a mystery. No conclusion is made from the experimental point of views. We systematically investigate the electromagnetic response of graphene at microwave frequencies, which are from direct current (DC) to 40 GHz. Both a coplanar transmission line embedded with different-sized graphene flakes of 48 x 48 and 48 x 240 μm2 and a microwave termination based on the graphene sheet of 6 x 6mm2 are manufactured through standard microfabrication procedures. We conclude that CVD graphene behaves as a frequency-independent surface resistance at the microwave frequencies, which is …

Ultrathin Complementary Metasurface For Orbital Angular Momentum Generation At Microwave Frequencies, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic (EM) waves with helical wave front carry orbital angular momentum (OAM), which is associated with the azimuthal phase of the complex electric field. OAM is a new degree of freedom in EM waves and is promising for channel multiplexing in the communication system. Although the OAM-carrying EM wave attracts more and more attention, the method of OAM generation at microwave frequencies still faces challenges, such as efficiency and simulation time. In this communication, by using the circuit theory and equivalence principle, we build two simplified models, one for a single scatter and one for the whole metasurface to predict …

Volterra Series-Based Time-Domain Macromodeling Of Nonlinear Circuits, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Jose E. Schutt-Aine, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

Volterra series (VS) representation is a powerful mathematical model for nonlinear circuits. However, the difficulties in determining higher order Volterra kernels limited its broader applications. In this paper, a systematic approach that enables a convenient extraction of Volterra kernels from X-parameters is presented. A concise and general representation of the output response due to arbitrary number of input tones is given. The relationship between Volterra kernels and X-parameters is explicitly formulated. An efficient frequency sweep scheme and an output frequency indexing scheme are provided. The least square linear regression method is employed to separate different orders of Volterra kernels at …

Review—The Current And Emerging Applications Of The Iii-Nitrides, Chuanle Zhou, Amirhossein Ghods, Vishal G. Saravade, Paresh V. Patel, Kelcy L. Yunghans, Cameron Ferguson, Yining Feng, Bahadir Kucukgok, Na Lu, Ian T. Ferguson

Electrical and Computer Engineering Faculty Research & Creative Works

III-Nitrides are attracting considerable attention as promising materials for a wide variety of applications due to their wide coverage of direct bandgap range, high electron mobility, high thermal stability and many other exceptional properties. The light-emitting diodes based on III-Nitrides revolutionize the solid-state lighting industry. III-Nitrides based solar cells, and thermoelectric generators support the sustainable energy progress, and the III-Nitrides are better alternatives for power and radio frequency (RF) electronics compared with silicon. The doped III-Nitrides' magnetic properties and sensitivity to radiation can contribute to novel spintronic and nuclear detection devices. This paper will review III-nitride material properties and their …

A Study Of Scattering From Snow Embedded With Non-Spherical Shapes Of Scatterers With Relaxed Hierarchical Equivalent Source Algorithm (Rhesa), Chan Fai Lum, Fu Xin, Hong Tat Ewe, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Remote sensing has been used widely in studying the earth terrain such as snow or sea ice due to its fast, convenient and long-term monitoring capabilities. SAR images acquired could be used to analyze the condition of snow, snow water equivalent (SWE), surface roughness and others. Theoretical models have also been developed to understand how microwave interacts with the snow medium and the scatterers embedded inside the medium. Conventionally, spherical shape of scatterers is commonly used to represent the ice particles embedded inside snow where the actual shape of scatterers can vary. This paper is to present a theoretical model …

The Error Control Of Mixed-Form Fast Multipole Algorithm Based On The High-Order Multipole Rotation, Ling Ling Meng, Xiaoyan Y.Z. Xiong, Tian Xia, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, the mixed-form fast multipole algorithm (MF-FMA) with feasible error controllability is implemented through high-order multipole rotation that can make the translation matrices very sparse. The saving of both storage and CPU time makes it attainable to increase the number of harmonics in the middle frequency regime, thus shifting up the transition region of MF-FMA. Consequently, the broadband accuracy of the MF-FMA can be improved significantly.

The Ill-Nitrides As A Universal Compound Semiconductor Material: A Review, Chuanle Zhou, Amirhossein Ghods, Vishal G. Saravade, Paresh V. Patel, Kelcy L. Yunghans, Cameron Ferguson, Yining Feng, Xiaodong Jiang, Bahadir Kucukgok, Na Lu, Ian T. Ferguson

Electrical and Computer Engineering Faculty Research & Creative Works

III-nitrides are attracting considerable attention as promising materials for a wide variety of applications due to their wide coverage of direct bandgap range, high electron mobility, high thermal stability and many other exceptional properties. The light-emitting diodes based on Ill-nitrides revolutionize the solid-state lighting industry. Ill-nitrides based solar cells, and thermoelectric generators support the sustainable energy progress, and the III-nitrides are better alternatives for power and radio frequency (RF) electronics compared with silicon. The doped Ill-nitrides' magnetic properties and sensitivity to radiation can contribute to novel spintronic and nuclear detection devices. This paper will review Ill-nitride material properties and their …

Silicon Carbide Based Surface Plasmon Resonance Waveguide Sensor With A Bimetallic Layer For Improved Sensitivity, Wei Du, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, silicon carbide (SiC) waveguide-based surface plasmon resonance optical sensor with an Ag-Au bilayer metal configuration was studied. The wide bandgap energy of SiC allows the sensor to operate in visible and near-infrared range. The spectrum of resonant wavelength with refractive index shows improved sensitivity and sensing resolution in the Au-Ag bilayer configuration than in the single Au layer configuration. A sensitivity of 2581 nm/RIU (refractive index unit) indicated by the shift of resonant wavelength with refractive index was observed from a refractive index range of n=1.34–1.36, showing that the sensor is desirable for sensing in a series …

Decision Process In Mcdm With Large Number Of Criteria And Heterogeneous Risk Preferences, Jian Liu, Hong Kuan Zhao, Zhao Bin Li, Si Feng Liu

Electrical and Computer Engineering Faculty Research & Creative Works

A new decision process is proposed to address the challenge that a large number of criteria in the multi-criteria decision making (MCDM) problem and the decision makers with heterogeneous risk preferences. First, from the perspective of objective data, the effective criteria are extracted based on the similarity relations between criterion values and the criteria are weighted, respectively. Second, the corresponding types of theoretic model of risk preferences expectations will be built, based on the possibility and similarity between criterion values to solve the problem for different interval numbers with the same expectation. Then, the risk preferences (Risk-seeking, risk-neutral and risk-aversion) …

Enhancements In Localized Classification For Uterine Cervical Cancer Digital Histology Image Assessment, Peng Guo, Haidar A. Almubarak, Koyel Banerjee, R. Joe Stanley, L. Rodney Long, Sameer K. Antani, George R. Thoma, Rosemary E. Zuna, Shelliane R. Frazier, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

Background: In previous research, we introduced an automated, localized, fusion-based approach for classifying uterine cervix squamous epithelium into Normal, CIN1, CIN2, and CIN3 grades of cervical intraepithelial neoplasia (CIN) based on digitized histology image analysis. As part of the CIN assessment process, acellular and atypical cell concentration features were computed from vertical segment partitions of the epithelium region to quantize the relative distribution of nuclei.

Methods: Feature data was extracted from 610 individual segments from 61 images for epithelium classification into categories of Normal, CIN1, CIN2, and CIN3. The classification results were compared against CIN labels obtained from two pathologists …

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

Electrical and Computer Engineering Faculty Research & Creative Works

This communication proposes a novel dual-beam dielectric grating antenna based on the supercell (SC) concept. Through the theoretical analysis of the effective phase constants of the SC, it is found that two space harmonic modes (m=-1 and m=-2) can be simultaneously excited (above the air line) within a certain frequency range. This phenomenon leads to the generation of two radiation beams in the far-field region. At the frequency where the phase constants satisfy β-1=-β-2, the two beams are in symmetric directions with respect to the axis that is perpendicular to the azimuth plane. Different from the conventional periodic structures that …

A Family Of Optimized Lms-Based Algorithms For System Identification, Silviu Ciochinǎ, Constantin Paleologu, Jacob Benesty, Steven L. Grant, Andrei Anghel

Electrical and Computer Engineering Faculty Research & Creative Works

The performance of the least-mean-square (LMS) algorithm is governed by its step-size parameter. In this paper, we present a family of optimized LMS-based algorithms (in terms of the step-size control), in the context of system identification. A time-variant system model is considered, and the optimization criterion is based on the minimization of the system misalignment. Simulations performed in the context of acoustic echo cancellation indicate that these algorithms achieve a proper compromise in terms of fast convergence/tracking and low mis adjustment.

Strongly Enhanced And Directionally Tunable Second-Harmonic Radiation From A Plasmonic Particle-In-Cavity Nanoantenna, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha, Yat Hei Lo, Ming Fang, Weng Cho Chew, Wallace C.H. Choy

Electrical and Computer Engineering Faculty Research & Creative Works

Second-harmonic (SH) generation is tremendously important for nonlinear sensing, microscopy, and communication systems. One of the great challenges of current designs is to enhance the SH signal and simultaneously tune its radiation direction with a high directivity. In contrast to the linear plasmonic scattering dominated by a bulk dipolar mode, a complex surface-induced multipolar source at the doubled frequency sets a fundamental limit to control the SH radiation from metallic nanostructures. In this work, we harness a plasmonic hybridization mechanism together with a special selection rule governing the SH radiation to achieve the high-intensity and tunable-direction emission by a metallic …

A Study Of Scattering From A Layer Of Random Discrete Medium With Hierarchical Equivalent Source Algorithm (Hesa), Chan Fai Lum, Fu Xin, Hong Tat Ewe, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper is to present a new numerical method which can be used in computational electromagnetics in microwave remote sensing of random discrete medium embedded with irregular shape of scatterers. Current Radiative Transfer (RT) theoretical modeling is normally used to simulate wave propagation in the medium and wave scattering by basic shapes of scatterers, e.g., cylinder, disk, needle or sphere where the scattering of those scatterers was normally derived analytically with some assumption and approximation. To simulate the total backscattering coefficient from a layer of random medium, traditionally it was quite common that Mie phase matrix was used to compute …

Right-Hand Side Effect On The Convergence Of Integral Equation Based Systems, Qin S. Liu, Sheng Sun, Weng Cho Chew, Qi I. Dai, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A study of the right-hand side effect for an iterative solver is presented. The right-hand side determines whether a mode can be excited under certain excitation. Based on the matrix equation system Ā · x = b, different formulations are discussed including the electric field integral equation (EFIE), Calderón preconditioned EFIE with electro-quasi-static problems, and the magnetic integral equation (MFIE) with magneto-quasi-static problems. Detailed spectral analysis shows the importance of the weighted right-hand side effect in both the convergence and accuracy of iterative system.

Polarization Control By Using Anisotropic 3-D Chiral Structures, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha, Wallace C.H. Choy, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the mirror symmetry breaking, chiral structures show fantastic electromagnetic (EM) properties involving negative refraction, giant optical activity, circular dichroism and asymmetric transmission. Aligned electric and magnetic dipoles excited in chiral structures contribute to the extraordinary properties. However, the chiral structures that exhibit n -fold rotational symmetry show a limited tunability of the chirality. In this paper, we propose a compact, light, and highly tunable anisotropic chiral structure to overcome this limitation and realize a linear-to-circular polarization conversion. The anisotropy is due to simultaneous excitations of two different pairs of aligned electric and magnetic dipoles. The 3-D omega-shaped structure, …

Operator Splitting For Quasi-Linear Abstract Hyperbolic Equation, N. Dikhaminjia, J. Rogava, Mikheil Tsiklauri

Electrical and Computer Engineering Faculty Research & Creative Works

We consider an abstract hyperbolic equation with a Lipschitz continuous operator, where the main operator is self-adjoint and positive definite and represents a sum of two similar operators. For this equation, we construct a decomposition scheme of high order of accuracy. This scheme is based on rational splitting of cosine-operator function.

A Novel Coordinate Transformation Based Self-Coupling Computation Approach For The Method Of Moments, Li Li, Lijun Jiang, Sheng Sun, Thomas F. Eibert, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

A new highly accurate and efficient coordinate transformation algorithm is proposed for the evaluation of the self-coupling in the Method of Moments (MoM), which produces usually the strongest contributions to the MoM system matrices. The new algorithm provides an effective solution to remove the singularity due to the Green's function inside the self-couplings. Moreover, the new solution reduces the integral dimension from 4-D to 1-D. Thus, better accuracy and efficiency are obtained for the self-coupling integrals.

A Patch-Resonator-Based Butler Matrix With New Triangular Phase Shifters, Xianshi Jing, Li (Lijun) Jun Jiang, Sheng Sun, Lei Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new novel patch based Butler Matrix using 3-dB square-patch coupler and triangular-patch wideband phase shifter is presented. By inserting a via hole along the symmetrical plane of the triangular patch, the bandwidth of the transmitting response is significantly increased. In order to obtain a 45° phase difference and a wideband phase response, a reference line with high characteristic impedance is applied and the length of the feeding line for the triangular-patch structure is adjusted correspondingly. As an application, a patch-based Butler Matrix is designed and fabricated around 4 GHz. The measured patch-based Butler Matrix shows a …

A Highly Tunable Sub-Wavelength Chiral Structure For Circular Polarizer, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

Chiral structures are composed of periodically arranged asymmetric particles. The asymmetry of chiral particles results in extraordinary properties like negative refraction index, giant optical activity and circular dichroism. Consequently, they have applications in super lens and various polarization controllers. There are two types of chiral structures, namely planar and 3D structures. The planar ones usually have three- or fourfold rotational symmetry, which limits the polarization tuning capability. On the other hand, the 3D prototypes are difficult to fabricate and measure. Here, we propose a highly tunable sub-wavelength 3D chiral structure. It can be conveniently manufactured on the single-layer double-side printed …

Stochastic Galerkin Methods For Transient Maxwell's Equations With Random Geometries, Yongtao Cheng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The generalized polynomial chaos expansion was broadly introduced to model systems with uncertain inputs, including random material properties and random computational geometries. This paper focuses solving electromagnetic field when the geometry contains multi-randomness. A linear transformation always maps spatial random variables into grids with fixed length. Hence a great advantage of the method is that the numerical mesh is not changed despite geometrical variations. We applied efficient stochastic Galerkin methods to time-domain Maxwell's equations when thicknesses of two-layer media are uncertain. High-order Runge-Kutta discontinuous Galerkin methods were performed on the resulting system of the expansion coefficients.

Characteristic Analysis For Optical Antennas: A Generalized Equivalent Circuit Model For Nanoparticles, Ying S. Cao, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Optical antennas, which are considered for many potential applications, are antennas which work at optical frequencies. At this frequency range, the materials, such as Al, Ag, Au and so on, formerly treated as perfect electric conductor (PEC), now have dispersive and complex permittivity, which complicates most of the methodologies. In this paper, a generalized equivalent circuit model is developed for nanoantennas not only to deal with the dispersivity of permittivity, but also to provide more physical insight. Several examples are used to benchmark the method.