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Electrical and Computer Engineering Faculty Research & Creative Works

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Articles 1351 - 1380 of 3518

Full-Text Articles in Engineering

Practical Linear Precoder Design For Finite Alphabet Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing With Experiment Validation, Yahong Rosa Zheng, Mingxi Wang, Weiliang Zeng, Chengshan Xiao Aug 2013

Practical Linear Precoder Design For Finite Alphabet Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing With Experiment Validation, Yahong Rosa Zheng, Mingxi Wang, Weiliang Zeng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A low complexity precoding method is proposed for practical multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems. Based on the two-step optimal precoder design algorithm that maximizes the lower bound of the mutual information with finite-alphabet inputs, the proposed method simplifies the precoder design by fixing the right singular vectors of the precoder matrix, eliminating the iterative optimization between the two steps, and discretizing the search space of the power allocation vector. For a 4 x 4 channel, the computational complexity of the proposed precoder design is reduced to 3 and 6% of that required by the original two-step algorithm …

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Optimized Waveform Relaxation Solution Of Rlcg Transmission Line Type Circuits, Mohammad D. Al-Khaleel, Martin J. Gander, Albert E. Ruehli Aug 2013

Optimized Waveform Relaxation Solution Of Rlcg Transmission Line Type Circuits, Mohammad D. Al-Khaleel, Martin J. Gander, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Today, parallel processing is necessary for the solution of large systems of ordinary differential equations (ODEs) as they are obtained from large electronic circuits or from discretizing partial differential equations (PDEs). Using a fine mesh in the discretization of these problems also leads to large compute times and large storage requirements. The waveform relaxation (WR) technique, which is ideally suited for the use of multiple processors for problems with multiple time scales has been used to solve such problems on parallel processors for such large systems of ODEs. However, applying the so-called classical WR techniques to strongly coupled systems leads …

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Partial And Internal Inductance: Two Of Clayton R. Paul's Many Passions, Christopher L. Holloway, Edward F. Kuester, Albert E. Ruehli, Giulio Antonini Aug 2013

Partial And Internal Inductance: Two Of Clayton R. Paul's Many Passions, Christopher L. Holloway, Edward F. Kuester, Albert E. Ruehli, Giulio Antonini

Electrical and Computer Engineering Faculty Research & Creative Works

Inductance is one of the fundamental defined parameters in electromagnetics and it takes on a variety of formulations and definitions in the electromagnetic compatibility (EMC) community. The concept of inductance in its many definitions, uses, and caveats was central among Dr. Clayton R. Paul's contributions to the EMC community. In this paper, we discuss the various aspects of inductance which Dr. Paul helped to pioneer. In particular, the concepts of partial inductance and internal inductance (including skin effect) were two of his passions. This paper will both serve as a summary of Dr. Paul's work on inductance as well as …

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Through-Silicon Via Fault-Tolerant Clock Networks For 3-D Ics, Chiao Ling Lung, Yu Shih Su, Hsih Hsiu Huang, Yiyu Shi, Shih Chieh Chang Jul 2013

Through-Silicon Via Fault-Tolerant Clock Networks For 3-D Ics, Chiao Ling Lung, Yu Shih Su, Hsih Hsiu Huang, Yiyu Shi, Shih Chieh Chang

Electrical and Computer Engineering Faculty Research & Creative Works

Clock network synthesis is one of the most important and challenging problems in 3-D ICs. The clock signals have to be delivered by through-silicon vias (TSVs) to different tiers with minimum skew. While there are a few related works in literature, none consider the reliability of TSVs in a clock tree. Accordingly, the failure of any TSV in the clock tree yields a bad chip. The naive solution using double-TSV can alleviate the problem, but the significant area overhead renders it less practical for large designs. In this paper, we propose a novel TSV fault-tolerant unit (TFU) to provide tolerance …

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Model Order Reduction For Multiband Quantum Transport Simulations And Its Application To P-Type Junctionless Transistors, Jun Z. Huang, Weng Cho Chew, Jie Peng, Chi Yung Yam, Li (Lijun) Jun Jiang, Guan Hua Chen Jul 2013

Model Order Reduction For Multiband Quantum Transport Simulations And Its Application To P-Type Junctionless Transistors, Jun Z. Huang, Weng Cho Chew, Jie Peng, Chi Yung Yam, Li (Lijun) Jun Jiang, Guan Hua Chen

Electrical and Computer Engineering Faculty Research & Creative Works

An efficient method is developed for multiband simulation of quantum transport in nanowire electronic devices within nonequilibrium Green's function formalism. The efficiency relies on a model order reduction technique, which projects the k.p Hamiltonian into a much smaller subspace constructed by sampling the Bloch modes of each cross-section layer. Several sampling approaches are discussed to obtain a minimum and accurate basis with reduced computational overhead. The technique is verified by calculating the valence bands of silicon nanowires (SiNWs) and by solving I-V curves of p-type SiNW transistors. This enables us to study for the first time the performances of large …

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Fiber Pigtailed Thin Wall Capillary Coupler For Excitation Of Microsphere Wgm Resonator, Haining Wang, Xinwei Lan, Jie Huang, Lei Yuan, Cheol-Woon Kim, Hai Xiao Jul 2013

Fiber Pigtailed Thin Wall Capillary Coupler For Excitation Of Microsphere Wgm Resonator, Haining Wang, Xinwei Lan, Jie Huang, Lei Yuan, Cheol-Woon Kim, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 x 104 was observed using a borosilicate glass microsphere with a diameter of 71 µm. The …

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Microwave Assisted Reconstruction Of Optical Interferograms For Distributed Fiber Optic Sensing, Jie Huang, Lei Hua, Xinwei Lan, Tao Wei, Hai Xiao Jul 2013

Microwave Assisted Reconstruction Of Optical Interferograms For Distributed Fiber Optic Sensing, Jie Huang, Lei Hua, Xinwei Lan, Tao Wei, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports a distributed fiber optic sensing technique through microwave assisted separation and reconstruction of optical interferograms in spectrum domain. The approach involves sending a microwave-modulated optical signal through cascaded fiber optic interferometers. The microwave signal was used to resolve the position and reflectivity of each sensor along the optical fiber. By sweeping the optical wavelength and detecting the modulation signal, the optical spectrum of each sensor can be reconstructed. Three cascaded fiber optic extrinsic Fabry-Perot interferometric sensors were used to prove the concept. Their microwave-reconstructed interferogram matched well with those recorded individually using an optical spectrum analyzer. The …

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Fixed Final Time Optimal Adaptive Control Of Linear Discrete-Time Systems In Input-Output Form, Qiming Zhao, Hao Xu, S. Jagannathan Jul 2013

Fixed Final Time Optimal Adaptive Control Of Linear Discrete-Time Systems In Input-Output Form, Qiming Zhao, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the fixed final time adaptive optimal regulation of discrete-time linear systems with unknown system dynamics is addressed. First, by transforming the linear systems into the input/output form, the adaptive optimal control design depends only on the measured outputs and past inputs instead of state measurements. Next, due to the time-varying nature of finite-horizon, a novel online adaptive estimator is proposed by utilizing an online approximator to relax the requirement on the system dynamics. An additional error term corresponding to the terminal constraint is defined and minimized overtime. No policy/value iteration is performed by the novel parameter update …

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An Engineering Physics Introduction To Electronics For Ece Sophomores, Steve Eugene Watkins Jun 2013

An Engineering Physics Introduction To Electronics For Ece Sophomores, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

Electronic devices and circuits are fundamental parts of undergraduate curricula in electrical engineering and computer engineering (ECE). A sophomore-level course that gives a balanced treatment of semiconductor device physics and electronic circuit analysis is described. The course topics are semiconductor physics, diodes, transistors, operational amplifiers, and optoelectronics. The course is a prerequisite for upper-level electronics, semiconductor physics, and semiconductor circuit layout curricula. A stronger link between physical principles and device behavior and an improved sequence in electronics instruction are outcomes.

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Hs3dpg: Hierarchical Simulation For 3d P/G Network, Shuai Tao, Xiaoming Chen, Yu Wang, Yuchun Ma, Yiyu Shi May 2013

Hs3dpg: Hierarchical Simulation For 3d P/G Network, Shuai Tao, Xiaoming Chen, Yu Wang, Yuchun Ma, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

As different chips are stacked together in 3D ICs, the power/ground (P/G) network simulation becomes more challenging than that of 2D cases. In this paper, we propose a hierarchical simulation method suitable for 3D P/G network (HS3DPG), which can ensure full parallelism and good scalability with the number of tiers. In the IR drop analysis, when there are 9 tiers, the hierarchical method can be 6.5 times faster than the direct full network simulation. The accuracy of HS3DPG has been verified by a 3D P/G network from the industrial design. Besides, we introduce the 'locality' property into HS3DPG to further …

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Localization Of Rfid Tags Using Stochastic Tunneling, M. R. Basheer, S. Jagannathan May 2013

Localization Of Rfid Tags Using Stochastic Tunneling, M. R. Basheer, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel localization scheme in the 3D wireless domain that employs cross correlation in backscattered signal power from a cluster of radio frequency identification (RFID) tags to estimate their location. Spatially co-located RFID tags, energized by a common tag reader, exhibit correlation in their received signal strength indicator (RSSI) values. Hence, for a cluster of RFID tags, the posterior distribution of their unknown radial separation is derived as a function of the measured RSSI correlations between them. The global maxima of this posterior distribution represent the actual radial separation between the RFID tags. The radial separations are …

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Surface Waves In Three-Dimensional Electromagnetic Composites And Their Effect On Homogenization, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Vadim A. Markel, Igor Tsukerman May 2013

Surface Waves In Three-Dimensional Electromagnetic Composites And Their Effect On Homogenization, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Vadim A. Markel, Igor Tsukerman

Electrical and Computer Engineering Faculty Research & Creative Works

Reflection and transmission of electromagnetic waves at the boundaries of periodic composites (electromagnetic/optical metamaterials) depends in general on both bulk and surface waves. We investigate the interplay of these two contributions using three-dimensional full-wave numerical simulations and a recently developed non-asymptotic homoge-nization theory. © 2013 Optical Society of America.

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A Numerically Efficient Formulation For Time-Domain Electromagnetic- Semiconductor Cosimulation For Fast-Transient Systems, Quan Chen, Wim Schoenmaker, Guanhua Chen, Lijun Jiang, Ngai Wong May 2013

A Numerically Efficient Formulation For Time-Domain Electromagnetic- Semiconductor Cosimulation For Fast-Transient Systems, Quan Chen, Wim Schoenmaker, Guanhua Chen, Lijun Jiang, Ngai Wong

Electrical and Computer Engineering Faculty Research & Creative Works

We report recent progress in developing a numerically efficient formulation for electromagnetic-technology computer-aided design cosimulation for fast-transient computations. The difficulties underlying the currently existing transient formulation stemming from the vector potential-scalar potential (A-V) framework are analyzed. A time-domain electric field-scalar potential (E-V) framework is then developed via equation and variable transformations. This results in better-conditioned systems that are friendly to iterative solutions at fast switching times. Numerical examples show that the proposed E-V solver renders a useful tool for addressing multidomain simulation. © 1982-2012 IEEE.

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Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn Apr 2013

Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn

Electrical and Computer Engineering Faculty Research & Creative Works

We demonstrate a device process combining two photo patternable polymers, poly (ethylene glycol) (PEG)-diacrylate-based-hydrogel and epoxy-based photoresist SU-8, to implement an optofluidic bioanalytical platform through a surface anchoring technique. As an exemplary sensor application, optical dissolved oxygen sensors are fabricated and their performance characterized. The PEG-rich hydrogel is used as a matrix material for the immobilization of oxygen-responsive fluorophore, dichlorotris (1, 10-phenanthroline) ruthenium (II) hydrate. This hydrogel is chemically anchored on the surface of negative-tone photoresist, SU-8, through a free radical reaction in which 1-hydroxycyclohexyl phenyl ketone served as the surface bound photo initiator. The sensor exhibits a reversible Stern-Volmer …

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A Wideband Microstrip To Bilateral Slotline Transition Using Constant Impedance Bilateral Slotline And Heart-Shaped Irregular Cavity, Fenghan Lin, Yong Chang Jiao, Yihong Qi Apr 2013

A Wideband Microstrip To Bilateral Slotline Transition Using Constant Impedance Bilateral Slotline And Heart-Shaped Irregular Cavity, Fenghan Lin, Yong Chang Jiao, Yihong Qi

Electrical and Computer Engineering Faculty Research & Creative Works

A microstrip to bilateral slot line (BS) transition is proposed in this letter, which contains a 50-Ω constant impedance BS and a heart-shaped slot line cavity. Unlike traditional slot line transitions, the proposed transition does not suffer from matching issues when losses are incurred by multi-section impedance transformers and this transition has a potential to operate from 530 MHz to over 20 GHz if a K-connector is used. This letter will illustrate the discovery of BS with constant impedance first and then its application in design of the 50-Ω BS. The heart-shaped slot line cavity is proposed for bandwidth improvement. …

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Modeling Local Via Structures Using Innovative Peec Formulation Based On Cavity Green's Functions With Wave Port Excitation, Hanfeng Wang, Jun Fan Apr 2013

Modeling Local Via Structures Using Innovative Peec Formulation Based On Cavity Green's Functions With Wave Port Excitation, Hanfeng Wang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Complex via structures such as noncircular antipads are rigorously studied, in the local region close to vias, using an innovative partial-element equivalent-circuit (PEEC) formulation based on the cavity Green's functions. The problem under study is an essential building block that can be used to model complex multilayer structures. With the usage of the cavity Green's functions, the number of unknowns is significantly reduced. Further, nonorthogonal quadrilateral mesh is used to better accommodate the complex shape of the antipads in practical designs. A novel wave port excitation method is proposed, which is new for the PEEC formulations. Singularity extraction in self-element …

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Economic Modeling Of Compressed Air Energy Storage, Yang Gu, James D. Mccalley, Ming Ni, Rui Bo Apr 2013

Economic Modeling Of Compressed Air Energy Storage, Yang Gu, James D. Mccalley, Ming Ni, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES) in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system …

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Neural Network-Based Optimal Adaptive Output Feedback Control Of A Helicopter Uav, David Nodland, Hassan Zargarzadeh, Sarangapani Jagannathan Apr 2013

Neural Network-Based Optimal Adaptive Output Feedback Control Of A Helicopter Uav, David Nodland, Hassan Zargarzadeh, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Helicopter unmanned aerial vehicles (UAVs) are widely used for both military and civilian operations. Because the helicopter UAVs are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via an output feedback for trajectory tracking of a helicopter UAV, using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers and an NN observer. The online approximator-based dynamic controller learns the infinite-horizon Hamilton-Jacobi-Bellman equation in continuous time and calculates the corresponding optimal control input by minimizing a cost function, forward-in-time, without using the …

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Quantum Network Theory Of Computing With Respect To Entangled Flux Qubits And External Perturbation, C. A. Cain, Cheng-Hsiao Wu Apr 2013

Quantum Network Theory Of Computing With Respect To Entangled Flux Qubits And External Perturbation, C. A. Cain, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we attempt to show the differences between traditional qubit-based spintronic methodology for quantum computation and the possible ballistic quantum network implementations. Flux qubits can be considered topologically similar to the persistent currents possessed as the angular momentum in Aharonov-Bohm loops, which can be coupled and thus entangled together. Since entanglement is guaranteed for coupled quantum networks, starting from a point-contacted situation, we first investigate how varying the degree of entanglement strength can affect the superposition of the four possible states for two isolated flux qubits being brought together. In general, the superposition is destroyed once the degree …

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Simulation And Detection Of Unintended Electromagnetic Emissions From Super-Regenerative Receivers, Jake Hertenstein, S. Jagannathan Mar 2013

Simulation And Detection Of Unintended Electromagnetic Emissions From Super-Regenerative Receivers, Jake Hertenstein, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel method for detecting the presence of the unintended electromagnetic emissions (UEE) from radio receivers is examined without a priori data or training. As an extension of previous research, the behavior of the super-regenerative receiver (SRR) is modeled and simulated with fractional Brownian noise to verify the detection model. This model shows that the presence of noise in the feedback circuit of the SRR is responsible for the characteristic frequency distribution of the receiver's UEE. A second-order self-similarity model is used to estimate the Hurst parameter as a detection threshold for the presence of long-range dependent noise that is …

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Modeling And Application Of Multi-Port Tsv Networks In 3-D Ic, Wei Yao, Siming Pan, Brice Achkir, Jun Fan, Lei He Mar 2013

Modeling And Application Of Multi-Port Tsv Networks In 3-D Ic, Wei Yao, Siming Pan, Brice Achkir, Jun Fan, Lei He

Electrical and Computer Engineering Faculty Research & Creative Works

Through-silicon-via (TSV) enables vertical connectivity between stacked chips or interposer and is a key technology for 3-D integrated circuits (ICs). While arrays of TSVs are needed in 3-D IC, there only exists a frequency-dependent resistance, inductance, conductance and capacitance circuit model for a pair of TSVs with coupling between them. In this paper, we develop a simple yet accurate circuit model for a multiport TSV network (e.g., coupled TSV array) by decomposing the network into a number of TSV pairs and then applying circuit models for each of them. We call the new model a pair-based model for the multiport …

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An Analytical Placement Framework For 3-D Ics And Its Extension On Thermal Awareness, Guojie Luo, Yiyu Shi, Jason Cong Mar 2013

An Analytical Placement Framework For 3-D Ics And Its Extension On Thermal Awareness, Guojie Luo, Yiyu Shi, Jason Cong

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we present a high-quality analytical 3-D placement framework. We propose using a Huber-based local smoothing technique to work with a Helmholtz-based global smoothing technique to handle the nonoverlapping constraints. The experimental results show that this analytical approach is effective for achieving tradeoffs between the wirelength and the through-silicon-via (TSV) number. Compared to the state-of-the-art 3-D placer ntuplace3d, our placer achieves more than 20% wirelength reduction, on average, with a similar number of TSVs. Furthermore, we extend this analytical 3-D placement framework with thermal awareness. While 2-D thermal-aware placement simply follows uniform power distribution to minimize temperature, we …

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Ff-Bond: Multi-Bit Flip-Flop Bonding At Placement, Chang Cheng Tsai, Yiyu Shi, Guojie Luo, Iris Hui Ru Jiang Mar 2013

Ff-Bond: Multi-Bit Flip-Flop Bonding At Placement, Chang Cheng Tsai, Yiyu Shi, Guojie Luo, Iris Hui Ru Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Clock power contributes a significant portion of chip power in modern IC design. Applying multi-bit flip-flops can effectively reduce clock power. State-of-the-artwork performs multi-bit flipflop clustering at the post-placement stage. However, the solution quality may be limited because the combinational gates are immovable during the clustering process. To overcome the deficiency, in this paper, we propose multi-bit flip-flop bonding at placement. Inspired by ionic bonding in Chemistry, we direct flipflops to merging friendly locations thus facilitating flip-flop merging. Experimental results show that our algorithm, called FF-Bond, can save 27% clock power on average. Compared with state-of-the-art post-placement multi-bit flip-flop clustering, …

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Real Time Bridge Scour Monitoring With Magneto-Inductive Field Coupling, Andriy V. Radchenko, David Pommerenke, Genda Chen, Pratik Maheshwari, Satyajeet R. Shinde, Viswa Pilla, Y. Rosa Zheng Mar 2013

Real Time Bridge Scour Monitoring With Magneto-Inductive Field Coupling, Andriy V. Radchenko, David Pommerenke, Genda Chen, Pratik Maheshwari, Satyajeet R. Shinde, Viswa Pilla, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Scour was responsible for most of the U.S. bridges that collapsed during the past 40 years. The maximum scour depth is the most critical parameter in bridge design and maintenance. Due to scouring and refilling of river-bed deposits, existing technologies face a challenge in measuring the maximum scour depth during a strong flood. In this study, a new methodology is proposed for real time scour monitoring of bridges. Smart Rocks with embedded electronics are deployed around the foundation of a bridge as field agents. With wireless communications, these sensors can send their position change information to a nearby mobile station. …

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Low-Complexity Turbo Detection For Single-Carrier Low-Density Parity-Check-Coded Multiple-Input Multiple-Output Underwater Acoustic Communications, Longbao Wang, Jun Tao, Chengshan Xiao, T. C. Yang Mar 2013

Low-Complexity Turbo Detection For Single-Carrier Low-Density Parity-Check-Coded Multiple-Input Multiple-Output Underwater Acoustic Communications, Longbao Wang, Jun Tao, Chengshan Xiao, T. C. Yang

Electrical and Computer Engineering Faculty Research & Creative Works

A low-complexity turbo detection scheme is proposed for single-carrier multiple-input multiple-output (MIMO) underwater acoustic (UWA) communications using low-density parity-check (LDPC) channel coding. The low complexity of the proposed detection algorithm is achieved in two aspects: first, the frequency-domain equalization technique is adopted, and it maintains a low complexity irrespective of the highly dispersive UWA channels; second, the computation of the soft equalizer output, in the form of extrinsic log-likelihood ratio, is performed with an approximating method, which further reduces the complexity. Moreover, attributed to the LDPC decoding, the turbo detection converges within only a few iterations. The proposed turbo detection …

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A Hybrid Electromagnetics-Circuit Simulation Method Exploiting Discontinuous Galerkin Finite Element Time Domain Method, Ping Li, Li (Lijun) Jun Jiang Feb 2013

A Hybrid Electromagnetics-Circuit Simulation Method Exploiting Discontinuous Galerkin Finite Element Time Domain Method, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid electromagnetics (EM)-circuit simulation method employing the discontinuous Galerkin finite element time domain (DGFETD) method is developed to model single lumped port networks comprised of both linear and non-linear elements. The whole computational domain is split into two subsystems: one is the EM subsystem that is analyzed by DGFETD, while another is the circuit subsystem that is modeled by the Modified Nodal Analysis method to generate a circuit subsystem. The coupling between the EM and circuit subsystems is achieved through a lumped port. Due to the local properties of DGFETD operations, only small coupling matrix equation systems are involved. …

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The Serial Resonant Antenna For The Large Field Of View Magnetic Resonance Imaging, Bo Zhu, Ed Xuekui Wu, Patrick Peng Gao, Peng Cao, Lijun Jiang Feb 2013

The Serial Resonant Antenna For The Large Field Of View Magnetic Resonance Imaging, Bo Zhu, Ed Xuekui Wu, Patrick Peng Gao, Peng Cao, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A serial resonant antenna for the large field of view (FOV) magnetic resonance imaging (MRI) is presented. It consists of metallic patches cascaded through lumped capacitors in serial on the top layer of a grounded dielectric substrate. The theoretical analysis show that at the resonant frequency, uniformly distributed current with zero phase delay is produced independent of the antenna length, hence a uniform magnetic field for large FOV MRI can be achieved. Integrated with the L-shaped tunable matching network, the antenna can be tuned easily to operate rigorously at the working frequency of the MRI system. The numerical modeling, physical …

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Online Optimal Control Of Nonaffine Nonlinear Discrete-Time Systems Without Using Value And Policy Iterations, Hassan Zargarzadeh, Qinmin Yang, S. Jagannathan Feb 2013

Online Optimal Control Of Nonaffine Nonlinear Discrete-Time Systems Without Using Value And Policy Iterations, Hassan Zargarzadeh, Qinmin Yang, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Online optimal control of nonlinear discrete-time systems in a forward-in-time manner is a challenging problem due to a lack of closed-form solution to the Hamilton- Bellman-Jacobi (HJB) equation. Traditionally, value and policy iteration-based approximate optimal control schemes are developed in the literature by assuming that a significant number of iterations can be performed within a sampling interval which is not practical. By contrast, this book chapter introduces a novel online time-based optimal framework for nonlinear discrete-time systems by using both: (a) reinforcement learning and (b) online neural network approximation-based forward-in-time dynamic programming without using iterative methodology. The overall stability proof …

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Joint Frequency-Domain Multiuser Turbo Equalization With Successive Interference Cancellation For Doubly-Selective Fading Channels, Jian Zhang, Yahong Rosa Zheng Feb 2013

Joint Frequency-Domain Multiuser Turbo Equalization With Successive Interference Cancellation For Doubly-Selective Fading Channels, Jian Zhang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

A novel multiuser separation and equalization scheme is proposed for single carrier wireless communication systems integrating frequency-domain (FD) multiuser turbo equalization (MUTE) and successive interference cancellation (SIC). The proposed iterative structure consists of multiple layers of detection, and at each layer the user with strongest power is processed by a frequency-domain multiuser equalizer to yield the soft extrinsic information on the coded bits of that user, which is delivered to a channel decoder after deinterleaving. The extrinsic information gleaned by the decoder is fed back to both the current and previous multiuser equalizers for the next iteration as a-priori information. …

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A Novel Fast Solver For Poisson's Equation With Neumann Boundary Condition, Zuhui Ma, Weng Cho Chew, Lijun Jiang Jan 2013

A Novel Fast Solver For Poisson's Equation With Neumann Boundary Condition, Zuhui Ma, Weng Cho Chew, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we present a novel fast method to solve Poisson's equation in an arbitrary two dimensional region with Neumann boundary condition, which are frequently encountered in solving electrostatic boundary problems. The basic idea is to solve the original Poisson's equation by a two-step procedure. In the first stage, we expand the electric field of interest by a set of tree basis functions and solve it with a fast tree solver in O(N) operations. The field such obtained, however, fails to expand the exact field because the tree basis is not curl-free. Despite of this, we can retrieve the …

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