Engineering Commons^™

An Analysis Of A Standardized Digital Circuit Driving A Coaxial Cable, John Pitkin Lappington

Masters Theses

"The expense of developing new circuit designs has forced electronic manufacturers to develop and use multipurpose circuits that can be adapted to fit many requirements. Sometimes this procedure leads to problems that would not have occurred if a circuit, designed to fit a particular application, had been developed. One problem of this type deals with the effect of improperly terminated coaxial cables loading output signals from a digital computer. The unterminated cable reflected the signal back in the computer. This did not affect the putout stage, but the preceeding [sic] driving stage was affected. The degradation of the output of …

Stochastic Simulations Analysis And Determination Of Iteration Requirements, James Walter Smith

Masters Theses

"A thorough analysis of computerized stochastic simulation problems has been undertaken to determine the number of iterations (or random draws) necessary to achieve a required degree of output accuracy. The basic problem is to determine when the sampled output mean and standard deviation are within specified accuracy limits. An error analysis is made of the statistical properties of deterministic-probablistic [sic] and logic (random walk) type problems. A recommendation for determining the number of problem iterations required is then presented"--Abstract, page ii.

A Lyapunov Designed Model-Referenced Control System With Signum Function Adaptive Control Laws, James Steven Epstein

Masters Theses

"An examination of a model-referenced adaptive control system designed to satisfy the requirements of Lyapunov's direct method is made. It is found that each adaptive control loop requires a multiplier for its implementation. A new design is proposed which replaces the multipliers in the control loops by switches, thereby gaining a significant hardware advantage. A first order system designed by the new method is simulated on an analog computer and some refinements are made. The method is then generalized to include nth order systems. The poles of the model, however, are subject to some restrictions. Finally, the problems associated with …

Investigation Of Target Detection In Noncoherent Systems With Colored Noise, Edward Windsor Bailey

Masters Theses

"Design efforts concerning the problem of detecting moving ground targets from an airborne platform with a noncoherent radar have been concentrated in the area of video filter design. The filter formulation generally follows an empirical path with no generally acceptable criterion for an optimum processor. This Thesis considers several problem formulations which are based on a Neyman-Pearson detection criteria. A square-law second detector is assumed and the resulting likelihood ratio shown to be too complex for closed form solution. The problem is reformulated in terms of sequences using complex random variable representations and the likelihood ratio is investigated. A test …

Failure Analysis Of Binary Address Decoders, Kanaiyalal Jekisondas Gandhi

Masters Theses

"This paper describes the organization and failure analysis of various types of binary address decoders. Logical type faults are considered and all possible faulty output patterns, resulting from these faults, are derived. A basic theory is developed, showing that these failure patterns are independent of the decoder size and organization. Digital simulation programs were used as an aid in the development of this theory. Results of the simulation are provided in the appendix"--Abstract, page ii.

Models For The Pn Diode And The Npn And Pnp Transistor For Use In Computer Aided Design And Analysis Programs, Glenn Ronald Case

Doctoral Dissertations

"This work is concerned with the problem of developing suitable mathematical representations for the pn junction diode and npn and pnp transistors for use in computer aided design and analysis programs. The Ebers-Moll model as used in the Net-1 program has been considerably improved, particularly regarding base resistance prediction, prediction of high forward current behavior, and the addition of reverse breakdown terms. The resulting models show substantial improvement in representation of d-c and transient characteristics. Some improvement in a-c characteristics has also been obtained. Methods of obtaining parameters for the new model and several of the present models, given measured …

Signal Distortion In A Regenerative Frequency Divider, Carl Ray Ryan

Doctoral Dissertations

"A regenerative frequency divider can be constructed with one integrated circuit and a single-pole tuned circuit. The divider can be used as a means for reducing the modulation index of either deterministic or random signals. This reduction in modulation index can simplify many signal processing schemes. This technique can be used up to S-band frequencies. The mathematical model of the regenerative frequency divider corresponds very closely to that of a first order Phase Locked Loop (PLL). The loop gain is determined in part by the nonlinear element used in the feedback loop. The loop gain is also proportional to the …

Spherical Antenna Array, Narong Yoothanom

Doctoral Dissertations

"The far field radiation pattern of an isotropic spherical antenna array with two types of element distributions, a latitude-longitude distribution and an approximately equally-spaced distribution, has been analyzed using Poisson's Sum Formula. Beamwidth expressions of both element distributions are found in various planes. All numerical results are given only for the case of 21 rings"--Abstract, page ii.

Improvement In Target Detection With A Frequency Agile Pulsed Non-Coherent Radar, Kenneth Lee Horn

Doctoral Dissertations

"Frequency agile tracking radars have received considerable attention in the literature. Frequency agility is useful in reducing target scintillations, thereby reducing tracking errors under certain conditions. However, little attention has been devoted to the improvement that can be expected in target detection with a frequency agile radar. In the past, complete pulse-to-pulse decorrelation of the target returns has been assumed for all of the analyses concerning target detection with frequency agile radars. This assumption always implies a transmitter with a large bandwidth.

This dissertation analyses a pulsed non-coherent frequency agile radar applied to Swerling's Case I target. The target model …

Direct Measurement Of Dynamic Capacitance, Norman G. Dillman

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

An Analysis And Comparison Of Linear Phase Bandpass Filters, Darrell L. Ash

Theses and Dissertations

The ideal bandpass filter is defined as one which uniformly attenuates and delays all frequency components within the passband and effects zero transmission of all components outside the passband. For reasons which will be subsequently discussed, it is impossible to realize a stable lumped-element filter having this ideal characteristic. This has made it necessary to find ways to physically approximate such a characteristic. Some of the more widely used methods will be compared and analyzed in this paper.

Semiconductor Nuclear Detectors, Lulio V. Guevara R.

Electrical and Computer Engineering ETDs

For the last 8 years the development of nuclear detectors have been shown to have the best potentialities over the other kind of nuclear counters. In this report we studied in general the characteristics of semiconductor nuclear counters and then we experimented with two types of semiconductor detectors, the surface barrier and the diffused junction detectors. Several materials were analyzed for the fabrication of these detectors. Silicon was finally chosen because of its advantages over other materials for fabrication of semiconductor counters, such as low cost and grade of purity. Silicon wafers, n-and p- type, were obtained from Monsanto Company. …

The Mechanism Of Second Breakdown In Transistors, Eugene David Fabricius

Dissertations

The purpose of this dissertation is to examine the behavior of electrons and holes in a semiconductor or diode under conditions of high current density as a function of temperature, and to relate this behavior to the phenomenon of Second Breakdown. The approach used is that of magnetohydrodynamics, the electrons and holes being treated as a plasma "gas" embedded in the dielectric of the semiconductor.

This approach is unique in the following respects:

1. This is the first attempt to explain second breakdown in terms of magnetohydrodynamics.
2. This is the first time an explanation of pinching in a solid at room …

Realization Of Transfer Impedances Using Distributed Rc Elements In A Common Ground Linvill Configuration, Walter Woronka

Theses

One of several synthesis procedures available for the realization of a transfer admittance is that of Linvill. This synthesis procedure employs an active element, a negative impedance converter (NIC), to shift the poles of passive immittance functions from the negative real axis into the complex plane to realize the desired transfer immittance function.

The Linvill synthesis procedure is extended to networks containing cascaded distributed RC elements and the conditions which must be satisfied to realize a transfer impedance using these distributed elements are defined.

A Study Of Delta Modulation And Its Application To Control Communication, Robert H. Maschhoff

Electrical and Computer Engineering ETDs

This thesis is a study of certain aspects of delta modulation which are of particular interest or significance in control system communication. Delta Modulation is a discrete difference encoding method in which the amplitude difference between the signals occurring at two points in time can be transmitted as a plus one or a minus one bit. Such a method of encoding has a rate of change capacity limit rather than a hard amplitude bound.

A determination of the sampling rates, and therefore bit rates, necess­ary to encode several types of signals is reported. Signals which themselves have a rate-limited characteristic …

The Development Of An Instrument For Three Dimensional Analysis Of Micron Quantities Of Tooth Movement, M. Clark Lamberton

Loma Linda University Electronic Theses, Dissertations & Projects

In order to quantitate initial tooth movement in response to forces applied to the tooth crown, an instrument for intraoral use has been developed. The photomicrometer consists of nine photosensitive cells mounted in an assembly of two layers. Eight of the cells were mounted to form X and Y axes, top layer and bottom layer, to measure horizontal movements. The ninth cell was mounted in the center of the bottom layer and was used for alignment and for measurements in the Z or vertical axis. The photocell assembly was approximately 10 mm diameter and 6 mm high. This assembly when …

Design Of Linear Control Systems With Distributed Parameter Elements By Parameter Plane Techniques, Murray Weinberg

Dissertations

This dissertation extends the application of parameter plane techniques to a number of areas. Specifically, the parameter plane technique can now be used to determine absolute stability, relative stability, and the location of roots of the closed-loop characteristic equation of systems containing both lumped and distributed parameter elements. The advantages of utilizing this technique are that results can be obtained as two system parameters are varied simultaneously and higher order systems can be treated as easily as low order ones.

Investigation of the mapping of real roots resulted in the derivation of a theorem which relates the number of real …

Noise Spectral Density As A Diagnostic Tool For Reliability Of P-N Junctions, Young Duck Kim

Dissertations

The feasibility of choosing noise-voltage spectral density as a prediction parameter for the degradation of p-n junctions has been examined both theoretically and through a series of life-tests.

Experimental facts show that the noise-voltage spectral density, S_v(w), observed in a p-n junction under the breakdown condition tends to be "white" (which contradicts the 1/f-noise theory), and S_v(w) is inversely proportional to the breakdown current (which contradicts the shot-noise theory). Furthermore, some p-n junctions display one or more multiple peaks of S_v(w) at different current levels which can not be explained by any of the …

An Analysis Of The Effects Of Ionizing Radiation In One-Dimensional Metal-Oxide-Semiconductor Structures, Charles William Gwyn

Electrical and Computer Engineering ETDs

Previous investigations of the radiation effects in Metal­Oxide-Semiconductor (MOS) devices have shown that ionizing radiation produces a trapped space charge in the oxide which causes a shift in the electrical characteristics of the device. Several models have been proposed to explain the observed change in the MOS device characteristics as a function of nuclear radiation exposure. Although these models have qualitatively explained the change in device characteristics, they have not adequately explained the physical processes producing the charge buildup nor have they considered the detailed conduction and charge trapping processes which exist in the various regions of an MOS structure. …

Magnetic Control Of Carrier Concentration In Semiconductors, S. Lee Hight

Electrical and Computer Engineering ETDs

Magnetic control of carrier lifetime in semiconductors has been examined from a standpoint of applying this phenomenon to low-voltage, high-current switching devices. The continuity equation is extensively examined for intrinsic semiconductors, and limits are derived on the magnitude of the switching effects in terms of material parameters. Experiments have been conducted on undoped indium antimonide which tend to verify these limits. A cursory examination is made of the control of the lifetime of injected carriers. The indications are that this effect may be useful in a wider range of materials than the effect in intrinsic semiconductors.

Electromagnetic Scattering From A Statistically Rough Spherical Surface With Shadowing, James Albert Doran

Electrical and Computer Engineering ETDs

Significant errors may be introduced into the theoretical calculation of scattered fields from a roughened sphere by the use of erroneously derived shadowing probabilities. These shadowing probabilities, of recent appearance in the literature, had been derived using an infinite plane as the mean surface. This paper undertakes the derivation of shadowing probabilities using a spherical mean surface. Although closed form expressions could not be obtained, computer evaluation of a "correction factor" showed that the errors incurred through use of the infinite plane probabilities (rather than the spherical surface) are insignificant. The class of rough surfaces considered was with a gaussian …

A Study Of The Properties Of The Biconical Antenna, Kurt Frank Hafner Jr.

Theses

Expressions are found for the fields produced by TM and TEM modes along a finitely conducting biconical antenna. Expressions are also found for the TM and TEM fileds along a biconical antenna having a lossy dielectric coating. It is shown that the antenna losses produce an anntenuation of the the fields along the antenna. It is found that because there is a dispersion of the fields along the biconical antenna, the attenuation produced by the losses is, in genaral, not characterized by simple exponential.

A solution is obtained for the fields of the TEM wave along a biconical antenna coated …

Fault Protection With A Digital Computer, George D. Rockefeller

Theses

A fundamental basis has been developed for the use of a time-shared stored-program digital computer to perform many of the electrical power-system protective-relay functions in a substation. Logic operations are given to detect a fault, locate it and initiate the opening of the appropriate circuit breakers, whether the fault is in the station or on lines radiating from the station.

The instantaneous value of the station voltages and currents are sampled at a 0.5 ms rate, converted to digital form and stored for computer main-frame use. Operating times are compatible with the 25 ms breaker trip capability of modern two-cycle …

A Technique For Determining Transistor Spall Thresholds., Herbert L. Floyd Jr.

Electrical and Computer Engineering ETDs

ABSTRACT

The purpose of the work described in this report was to develop a technique for determining the mechanical robustness of small electronic components when subjected to short duration stress waves. Techniques employed by other experimenters., which include flyer­plate impaction and pulsed-electron deposition., are difficult to control and to analyze. The procedure described herein overcomes these difficulties by restricting the variables that control accuracy to those which can be precisely measured.

The wave equation was derived and solved for deformable bodies subjected to unidimensional strain. In addition to providing insight into the dependence of high-tensile stress es on stress -wave …

The Gaussian Mode In Optical Resonators With A Radial Gain Profile, Lee W. Casperson, Amon Yariv

Electrical and Computer Engineering Faculty Publications and Presentations

The dependence of the parameters of the Gaussian mode in laser resonators on the properties of the medium in the cavity is studied. Experimental verification of the theoretical results is presented. It is found that the modes in a high‐gain laser may differ widely from the usual free space resonator results. Also, resonator configurations which in free space are unstable may, with a suitable medium, support low‐loss Gaussian modes.

Automation In The Design Of Asynchronous Sequential Circuits, Richard T. Smith, James H. Tracey, W. L. Schoeffel, G. K. Maki

Electrical and Computer Engineering Faculty Research & Creative Works

Sequential switching circuits are commonly classified as being either synchronous or asynchronous. Clock pulses synchronize the operations of the synchronous circuit. The operation of an asynchronous circuit is usually assumed to be independent of such clocks. The operating speed of an asynchronous circuit is thus limited only by basic device speed. One disadvantage of asynchronous circuit design has been the complexity of the synthesis procedures for large circuits.

Ptimal Feedback Control Of The Radioactive Voltage Standard, David William Braudaway

Electrical and Computer Engineering ETDs

The quest for new and different techniques of establishing and maintaining the electrical values is continual Among the techniques desired are those for producing highly predictable sources of voltage. Described in this dissertation is a working device developed around one such technique, the research done to define the system and the synthesis of the automatic control which makes it practical. In this system, the reproducibility of the voltage output is derived from the predictability of the decay of a radioactive heat source.

Transient Pulse Transmission Using Impedance Loaded Cyclindrical Antennas, David E. Merewether

Electrical and Computer Engineering ETDs

Two aspects of the problem of pulse transmission using impedance loaded cylindrical antennas have been considered. First, an approximate solution is obtained for the current distribution on a thin cylindrical antenna driven at an arbitrary point along its length. This solution may be applied to an antenna of any length, and its simplicity makes the current distribution rapidly computable. This solution is ideal for the prediction of the transient electromagnetic field radiated when an arbitrary voltage transient is impressed across the input terminals of a long, thin, cylindrical antenna loaded with lumped im­pedances. Second, an antenna synthesis procedure was evolved. …

A High Current Density Pulse-Mode Proton Source: Preliminary Study, Warren D. Smith

Electrical and Computer Engineering ETDs

A neutron source which produces high density pulses is useful, for example, in the simulation of an atomic blast or in neutron activation chemical analysis. Rather than forming pulses by deflecting the deuteron beam emitted from a continuous source of deuterons onto and off of a tritium target, it was decided to investigate the possibility of transient deuteron production. Proton sources were studied in place of deuteron sources because of the availability of hydrogen gas for experimentation. An experimental system was set up in which transient electrical discharges through hydrogen could take place. It was hoped that discharges could be …

The Effect Of Transient Ionizing Radiation Upon Schottky Barrier Diodes, Robert H. Schnurr

Electrical and Computer Engineering ETDs

The theory of operation of the Schottky barrier diode was reviewed. The complications caused by a more accurate space charge formulation were discussed. Consideration of image effects, tunneling, interfacial dielectric layers, surface states, and minority carrier current was also included.

The interaction of ionizing radiation with semiconducting materials was reviewed. The behavior of a Schottky barrier diode in an ionizing radiation environment was considered. The resultant model for the Schottky barrier diode is analogous to a p-n diode with one side having a very high dopant concentration.

Tests were performed upon GaAs and silicon Schottky barrier diodes, using a 2 …