Electrical and Computer Engineering Commons^™

Real-Time Implementation Of An Adaptive Control System For A 3-Zone Rapid Thermal Processing Station, David Hur

Theses

In this thesis, the implementation details of a real time adaptive control system for a TI 3-zone RTP station, as well as the simulation and the experimental results are presented. Extensive simulation of the system is performed in order to ensure proper operation of the system. The experimental results are used to verify proper operation of the closed loop control system. Initial experiments were conducted using two thermocouples. Further experiments were conducted using one thermocouple for the purpose of testing the performance of the system using Extended Kalman Filter as the state estimator.

The implementation of the control system is …

Residual Stress Analysis Of Sputtered Tantalum Silicide Thin Film, Young Joo Song

Theses

The influence of different argon pressures on the residual stress, microstructure, and resisitivity of sputtered tantalum silicide thin films has been investigated. TaSi₂ films were deposited onto Si wafers by dc magnetron sputtering. The deposition temperature was assumed to be 300°C. The thickness was about 0.5 μm. The residual stresses in the films deposited at different argon pressures were determined by curvature measurement method. The compressive intrinsic stress of 1033.4MPa was measured at P_Ar = 0.5 mTorr. The intrinsic stress in the films seemed to change from compression to tension as P_Ar increased above 8mTorr. A maximum …

A Digital Signal Processor Based Optical Position Sensor And Its Application To Flexible Beam Control, Thomas J. Spirock

Theses

A Digital Signal Processor (DSP) based optical position sensor was developed. The sensor system consists of the following components: 1) analog electronics, 2) the DSP based synchronous demodulation software, 3) PC based interface software which samples and saves the data, and 4) PC based control codes for a flexible beam. experiment.

The ability of the system to determine the distance from the optical sensor to the power modulated light source was assessed by the following tests: 1) a stationary drift test to evaluate the system's noise, 2) a short-range test to determine the resolution of the optical sensor over a …

The Study Of Sige-Channel Heterojunction Mos Device, Yunchen Qiu

Theses

The advances in the growth of pseudomorphic silicon-germanium epitaxial layer combined with the strong need for high-speed CMOS VLSI circuit have led to increased interest in silicon-based heterojunction MOSFET's transistors. The high-performance heterostructure SiGe MOSFET exhibits higher channel mobility than its bulk Si counterpart. The most critical and challenging process for fabricating a SiGe MOSFET device is that for making a gate oxide with sufficient quality for useful conductivity modulation. PECVD methods was employed to deposit the gate oxide and C-V method was used to investigate the electrical characteristics of the film. For PECVD gate oxide, a film refractive index …

Remote Measurement Calibration In Power System, Xiaofeng Li

Theses

Power system reliability and economy of operation require accurate measurements of current, voltage, real and reactive powers. These measurements are transmitted to a control center of a power system for monitoring, display, and use in power system real-time analysis. The number of measurements is in thousands. Routinely field technicians must calibrate transducers and/or determine other sources of metering errors. Due to the large number of measurements and the time required to check each individual measurement, field calibration procedures are impractical, expensive, and not timely.

There has been a need for a more efficient approach to measurement calibration and identification of …

Simple Fast Vector Quantization Of The Line Spectral Frequencies, Jin Zhou

Theses

Speech coding has been of interest to communication specialists for years. A number of technologies for describing and transmitting the speech spectral envelope have been studied. Among them, the Vector Quantization (VQ) of Line Spectral Frequencies (LSF) is receiving more attention because of its good rate-distortion performance. Typically, about 30 bits are assigned to code 10-dimensional LSF vectors with a resulting spectral distortion of less than ldB. However, 30-bit full-search VQ is totally impractical in terms of both computational complexity and memory space. Various standard suboptimal, low-complexity VQ techniques have been used for coding the LSF's in the literature. The …

The Development Of An Embedded Wireless Modem Conforming To Advanced Mobile Phone System And Cellular Digital Packet Data Standards, Xin Ren

Theses

Introduced by AT&T Bell Labs in 1970s, today Advanced Mobile Phone Systems (AMPS) - a first generation analog cellular system serve millions of customers in the United States and 55 other countries, and the number of subscribers is still rapidly increasing. Although digital cellular systems are emerging in recent years, research efforts are still being made to the enhancement of AMPS systems because of their popularity. An example is the new Cellular Digital Packet Data (CDPD) standard announced in 1994. CDPD is an overlay of the existing AMPS, and has the capability of transmitting data packets over such an analog …

Comparison Of Adaptive Radar Algorithms : Transformed Smi, Eigencanceler, And Smi, Chaitanya H. Kathiari

Theses

Advanced airborne radars must perform target detection in the presence of interference and heavy clutter. In many applications, the practical usefulness of adaptive arrays is limited by their convergence rate. In this paper, we first analyze the performance of the SMI method. Then, two other methods, the transformed SMI and the eigencanceler, both based on the principle component inversion (PCI) technique, are described and analyzed by simulation. It is shown by simulation based comparison that the transformed SMI and the Eigencanceler outperform the SMI method. It is also shown that the transformed SMI and the eigencanceler has higher convergence rate …

Linearly Tapered Slot Antenna, Luis Alberto Tumialan

Theses

Design procedure for Linearly Tapered Slot Antennas (LTSA) has been developed and implemented using High Frequency Structure Simulator (HFSS) code based on a finite-element analysis.

A CAD study of two variations of a LISA based on either a stripline or a microstrip feed has been carried out. Circular and radial stubs have been considered in these designs for an antenna operating at 10 Ghz. LTSA on a Duroid substrate fed by a stripline has been designed to operate with better than 12 dB return loss. Fabricated antenna was characterized and had even a wider response than the CAD design. Radiation …

Numerical Simulation Of Clipping Distortion In Lightwave Catv Systems, Luay Al-Nadi

Theses

Clipping induced distortion is an essential limit for modulation depth and number of channels in subcarrier multiplexed lightwave video transmission systems. Two different types of laser clipping are compared (single-clipping vs. double-clipping). In this work, the distortion limits imposed by clipping effects, in both directly (single-clipping) and externally (double-clipping) modulated systems, are examined. Numerical simulations were performed to test the efficiency of Saleh's Model. A comparison of results with clipping induced distortion in directly modulated lightwave systems (single-clipping) and clipping induced distortion in externally modulated lightwave systems (double-clipping) is presented, it is shown through numerical simulation that the total non-linear …

Implementation Of A Friction Estimation And Compensation Technique, Jayesh N. Amin

Theses

This thesis reports implementation of a friction estimation and compensation technique on a special laboratory apparatus. In this work, experimental results are reported for the Coulomb friction observer.

The Coulomb friction observer estimates the total friction present in a system, assuming it to be a constant function of velocity. An extension of the observer, utilizing a coupled velocity observer, is used when velocity is not measurable. A modification to the velocity observer is also implemented. Experimental results show a remarkable improvement in the friction estimates which are also compared to the actual friction measurements. The estimates are qualitatively similar to …

Analysis Of Calibration, Robustness, Detection Of Space-Time Adaptive Rada Using Experimental Data, Murat O. Berin

Theses

Signal cancellation effects in adaptive array radar are studied under non ideal conditions when there is a mismatch between the true desired signal and the presumed theoretical desired signal. This mismatch results in decreased performance when the estimated correlation matrix has a large desired signal component. The performance of the sample matrix inversion (SMI) method is compared to the eigenanalysis-based eigencanceler method. Both analytical results and the processing on the experimental data from the Mountaintop Program, show that eigenanalysis-based adaptive beamformers have greater robustness to signal cancellation effects than the SMI method. Also, the calibration of the recorded data, and …

Adaptive Radar In Heterogeneous Environment, Albert Futernik

Theses

Radar performance in heterogeneous clutter has been a much studied topic. In all the studies so far, various forms of the sample matrix inversion (SMI) technique where used to calculate the weight vector of the processor. In this thesis an eigenanalysis-based technique known as the eigencanceler, is used. Performance of this technique is compared to the performance of the generalized likelihood ration (GLR) processor. This comparison is done using the clutter edge model, in which there is an abrupt change in the clutter power in the reference window. It is shown that the false alarm rate fluctuations, of the cell …

Gabor Expansion Of An Equivalent Dipole Antenna, Oksana Manzhura

Theses

The Gabor representation in the context of an aperture problem is an expansion of a radiated field in terms of a discrete set of linearly shifted and spatially rotated elementary Gaussian beams. The parameters that can be varied in this summation are the number of beams and corresponding beam widths. As the difficulty associated with the unique determination of the expansion coefficients was alleviated, the method has been successfully applied to one and two dimensional apertures. Although, the asymptotic evaluation of expansion functions has reduced the computational burden drasticallym it was at the expense of some loss in accuracy. The …

Small Computer System Interface (Scsi) Universal Services For The Turbonet Parallel Computer, Artak Ohan Melkonian

Theses

TurboNet is a parallel computer with shared-memory and message-passing hybrid architecture. It employs two boards, with four digital signal processors (DSPs) each, and a host FORCE SPARC CPU-2CE board with a SCSI bus.

Software has been developed in this thesis to provide SCSI services to programs running on the DSPs. DSP programs can therefore fully control assigned SCSI devices at the SCSI command level. Transfer control modifiers ensure compatibility with most SCSI devices.

The software provides service for three SCSI access levels. The "su" SCSI universal device driver is built into the host computer's kernel and is a gateway to …

Design And Development Of Four To Sixteen Channel Video Multiplexers, Ronan Rahimi

Theses

Video multiplexer series were successfully designed and built for prototype and evaluation both in terms of hardware and software. The hardware platform was designed to accommodate up to sixteen color video input channels for time lapse or real time recording on a single video cassette recorder. This product implements four modes of operation; Live, Record, Playback and Menu mode, which is not a full mode of operation. Menu mode is a series of on-screen programming menus which appears on Live, Record and Playback modes. Menu mode enables the user to program the machine to work under specific modes of application. …

Configuring The Radial Basis Function Neural Network, Insoo Sohn

Theses

The most important factor in configuring an optimum radial basis function (RBF) network is the training of neural units in the hidden layer. Many algorithms have been proposed, e.g., competitive learning (CL), to train the hidden units. CL suffers from producing "dead-units." The other major factor Which was ignored in the past is the appropriate selection of the number of neural units in the hidden layer. The frequency sensitive competitive learning (FSCL) algorithm was proposed to alleviate the problem of dead-units, but it does not alleviate the latter problem. The rival penalized competitive learning (RPCL) algorithm is an improved version …

A Comparative Study Of Image Compress Schemes, Kui Wang

Theses

Image compression is an important and active area of signal processing. All popular image compression techniques consist of three stages: Image transformation, quantization (lossy compression only), and lossless coding (of quantized transform coefficients).

This thesis deals with a comparative study of several lossy image compression techniques. First, it reviews the well-known techniques of each stage. Starting with the first stage, the techniques of orthogonal block transformation and subband transform are described in detail. Then the quantization stage is described, followed by a brief review of the techniques for the third stage, lossless coding.

Then these different image compression techniques are …

Flash Adc Using 2Μm Cmos P-Well Technology : Design And Test, Joseph E. Levinson

Theses

This thesis describes the design, implementation and test for a new CMOS analog-to-digital converter IC chip. In designing the analog-to-digital converter in this thesis a radically different comparator design that is only available with CMOS logic. The design utilizes a single CMOS inverter as an ultra-high gain amplifier. This approach reduces the circuit dependence upon matching of the transistors similar to the traditional method. This new design requires less area since the comparator utilizes fewer transistors.

Flash analog-to-digital converters use 2" - 1 comparators to do a single conversion where n is the number of bits used. These comparators are …

A Simulation Environment For Cdma Wireless Communication Systems In Awgn Channels, Muzaffer Kanaan

Theses

The goal of this work is the development of a, wireless communication system simulator. The simulator has been developed primarily to aid in the studies of Code Division Multiple Access (CDMA) digital cellular systems. We begin by introducing the fundamentals of spread spectrum communications and the motivation for this work. We then take a detailed look at CDMA systems and their structure. We then verify the accuracy of the simulator by using it to simulate some familiar system scenarios. We end this work by presenting conclusions and suggestions for further work.

Asynchronous Multiuser Decorrelating Detector For Awgn Channel, Ashwini A. Borkar

Theses

Decorrelating detector is one of the sub-optimum detectors for CDMA applications that generally has better performance than the conventional detector and is near-far resistant. Synchronous decorrelating detector employing DPSK modulation is considered and its simulation results are presented.

Attention is focussed on one-shot decorrelating detector for a two user case for asynchronous transmission, where each symbol interval is considered seperately. Initially the performance of the detector with exact estimation of the relative delay is analyzed and then the effect of inaccurate estimation on the probability of error is discussed.