Engineering Commons^™

Theory And Experiment Of High-Speed Cross-Gain Modulation In Semiconductor Lasers, Xiaomin Jin, T. Keating, Shun-Lien Chuang

Electrical Engineering

We present theory and experiment for the high-speed modulation response of a quantum-well (QW) laser in the presence of an external microwave modulated optical pump in the gain region. The model includes the effects of pump-induced stimulated recombination and cross-gain saturation. Expressions for the small-signal modulation response of the test laser under gain modulation are derived. We also present experimental results using a multiple-QW InGaAlAs Fabry-Perot (FP) laser at 1.552 μm as the test laser and an external pump by a 1.542 μm DFB laser. Comparison between electrical modulation and optical cross-gain modulation (XGM) of the test laser is also …

A Technique For Analyzing Radiation From Conformal Antennas Mounted On Arbitrarily-Shaped Conducting Bodies, Dean Arakaki, Douglas H. Werner, Raj Mittra

Electrical Engineering

This paper presents an efficient method to solve the problem of radiation from conformal aperture and microstrip antennas mounted on arbitrarily-shaped conducting bodies. The method, based on the surface equivalence and reciprocity principles, uses a combination of the Finite Difference Time Domain (FDTD) and Method of Moments (MoM) techniques to substantially improve the computational efficiency of the radiation pattern calculation. When the geometry and location of the radiating element are modified, only a small portion of the overall analysis requires re-simulation. This leads to a significant improvement in computational efficiency over presently used techniques, and can substantially improve design efficiency …

Multi-Wavelength Polarization Scrambling Device, James R. Stimple, Dennis J. Derickson, Eugene Rudkevich

Electrical Engineering

A polarization scrambling device randomly varies the polarization states of multiple applied optical signals. The scrambling device includes a polarization scrambler coupled to a wavelength-dependent polarization randomizer having cascaded birefringent elements in which the axes of polarization of the cascaded elements are rotationally offset. The scrambling device causes random variations in the relative and the absolute polarization states of the applied optical signals. The birefringence, lengths, and number of cascaded birefringent elements are chosen to assure that the polarization states of optical signals at the different wavelengths are sufficiently randomized, even when the applied optical signals are closely spaced in …

A Multidisciplinary Polymer Electronics Laborary, David Braun, Kevin Kingsbury, Linda Vanasupa

Electrical Engineering

Semiconducting polymers blend several attractive features that enable inexpensive and unique applications. Forming the subjects of numerous research and development projects, semiconducting polymers also make excellent teaching tools. Since the materials and their applications benefit from intrinsically multidisciplinary approaches, polymer electronics exposes both students and faculty to fruitful interdisciplinary collaboration. This paper introduces semiconducting polymers, tours the Cal Poly polymer electronics lab facility, and summarizes lab projects and course modules completed to date.

Output Current Ripple Factor Performance Of Half-Wave Rectifier With And Without Freewheeling Diode, Taufik, Ali O. Shaban, Ahmad Nafisi

Electrical Engineering

The objective of this work is to investigate the ripple factor of half-wave rectifier circuits. The ripple factor is one of the important characteristics necessary when designing a power electronic converter. The ripple factor measures how much deviation the converter output parameter has, such as the output current, from its nominal designed value. In this paper the ripple factor of the output current of half-wave rectifiers is investigated. More specifically, the ripple factor of output current from more practical half-wave rectifiers that include inductive load with or without a freewheeling diode are analyzed and then compared to that of the …

Lip Feature Extraction Towards An Automatic Speechreading System, Xiaozheng Zhang, Russell M. Mersereau

Electrical Engineering

The use of color information can significantly improve efficiency and robustness of lip feature extraction capability over purely grayscale-based methods. Edge information provides another useful tool in characterizing lip boundaries. In this paper we present a method of integrating both types of information to address the problem of lip feature extraction for the purpose of speechreading. We first examine various color models and view hue as an effective descriptor to characterize the lips due to its invariance to luminance and human skin color, and its discriminative properties. We use prominent red hue as an indicator to locate the position of …

Relative Intensity Noise Characteristics Of Injection-Locked Semiconductor Lasers, Xiaomin Jin, Shun-Lien Chuang

Electrical Engineering

An experimental and theoretical study of relative intensity noise (RIN) spectra of side-mode injection-locked Fabry–Perot semiconductor lasers is reported. It is shown that the injection-locking technique effectively increases the relaxation oscillation frequency from 4.5 GHz (free-running mode) to 12 GHz (injection-locked mode) and enhances relaxation peaks of the slave laser RIN spectra. Results from our theoretical model, which include the key parameters for semiconductor quantum-well lasers, such as the linewidth enhancement factor, the nonlinear gain saturation coefficients, and optical confinement factor, show good agreement with our experimental results.

A Technique For Analyzing Radiation From Conformal Antennas Mounted On Arbitrarily-Shaped Conducting Bodies, Dean Arakaki, Douglas H. Werner, Raj Mittra

Electrical Engineering

This paper presents an efficient method to solve the problem of radiation from conformal aperture and microstrip antennas mounted on arbitrarily shaped conducting bodies. The method, based on the surface equivalence and reciprocity principles, uses a combination of the finite difference time domain (FDTD) and method of moments (MoM) techniques to substantially improve the computational efficiency of the radiation pattern calculation. When the geometry and location of the radiating element are modified, only a small portion of the overall analysis requires re-simulation. This leads to a significant improvement in computational efficiency over presently used techniques, and can substantially improve the …

A Method For Reducing The Variation In "On" Resistance Of A Mos Sampling Switch, A. K. Ong, Vladimir I. Prodanov, M. Tarsia

Electrical Engineering

Variation in the “on” resistance of a MOS sampling switch can introduce distortion into the front end of a switched-capacitor filter or analog-to-digital converter. We review three methods commonly used to linearize the resistance of a MOS switch and propose a new technique that addresses their limitations. A practical method for implementation is also suggested.

V-I Converters With Transconductance Proportional To Bias Current In Any Technology, Vladimir I. Prodanov

Electrical Engineering

In this paper we discuss circuits comprised of multiple differential pairs driven in parallel. We show that high linearity and linear with bias current tunability are intrinsic properties of any equidistant-offset multi-pair circuit. We argue that these two properties could potentially allow us to implement designs of analog filters, multipliers and other circuits that are (in first-order) technology independent. Simulations results are provided in support of presented simple intuitive explanation.

Steady State Operating Characteristics Of Hybrid Loaded Resonant Power Converter, Taufik

Electrical Engineering

No abstract provided.

Profiling The Performance Of Tcp/Ip On Windows Nt, P. Xie, M. Liu, J. Harris, C. Scheiman

Electrical Engineering

This paper presents detailed network performance measurements of a prototype implementation of the TCP/IP network software on Windows NT. The measurements include latency, throughput, and CPU utilization of the protocol stack and for some key operations within the stack

A Technique For Analyzing Radiation From Conformal Antennas Mounted On Arbitrarily-Shaped Conducting Bodies, Dean Arakaki, Douglas H. Werner, Raj Mittra

Electrical Engineering

This paper presents an efficient method to solve the problem of radiation from conformal aperture and microstrip antennas mounted on arbitrarily-shaped conducting bodies. The method, based on the surface equivalence and reciprocity principles, uses a combination of the Finite Difference Time Domain (FDTD) and Method of Moments (MoM) techniques to substantially improve the computational efficiency of the radiation pattern calculation. When the geometry and location of the radiating element are modified, only a small portion of the overall analysis requires re-simulation. This leads to a significant improvement in computational efficiency over presently-used techniques, and can substantially improve design efficiency when …

A Conformal Finite Difference Time Domain (Cfdtd) Algorithm For Modeling Perfectly Conducting Objects, Wenhua Yu, Raj Mittra, Dean Arakaki, Douglas H. Werner

Electrical Engineering

In this paper, the authors present a new and robust conformal Finite Difference Time Domain (FDTD) algorithm for the accurate modeling of perfectly conducting objects with curved surfaces and edges. We illustrate the application of this approach by analyzing a number of representative antenna and cavity problems. These include a quarter wave monopole mounted on a perfectly conducting elliptic disk, a circular patch antenna, and a cylindrical cavity. We validate the me~od by comparing the results for the pattern, impedance and resonant frequency, etc., with those derived by using other techniques.

Evaluation Of Infrared And Millimeter-Wave Imaging Technologies Applied To Traffic Management, C. Arthur Maccarley, Brian M. Hemme, Lawrence Klein

Electrical Engineering

This paper reviews the findings of a study commissioned by the California Department of Transportation to evaluate the potential of infrared and passive millimeter-wave imaging technologies for traffic surveillance and automated detection. Images formed from radiation at infrared and millimeter wavelengths are characterized by fundamentally different information compared with visible-spectrum images, and generally improved ability to penetrate obscured atmospheres such as fog or dust.

Ten examples of commercially available infrared (IR) imaging technologies and one experimental passive millimeter-wave (MMW) radiometric imaging apparatus were evaluated with respect to the specific requirements of highway monitoring and traffic management. A suite of traffic …

Electroluminescent Display Device Including Active Polymer Layer, Aemilianus G. J. Staring, David Braun, Karel E. Kuijk

Electrical Engineering

Control device for an electroluminescent display device, comprising an active layer of a semiconducting polymer of, for example pixels arranged in the form of a matrix, reducing flicker and crosstalk. The control device may be based on voltage control at which voltages across the pixels are at least 1.6 V, but is preferably based on current control, at which the duration of the data pulses determines the grey level.

A Review Of Battery Exchange Technology For Refueling Of Electric Vehicles, C. Arthur Maccarley

Electrical Engineering

The limited energy storage and long recharge time and of electric vehicle batteries have motivated several alternatives to in-vehicle slow charging. Solutions generally fall into three categories: (1) fast charging, in which batteries are charged in-vehicle at an accelerated rate, (2) battery material reloading or refueling, in which the energy-carrying elements of the battery are physically replaced or replenished, and (3) battery interchange, involving the complete exchange of the battery pack, usually with the aid of some semi-automated mechanism. Among these options, the last, battery interchange, has tended to receive the least industry attention, but has been an expansive topic …