Electrical and Computer Engineering Commons^™

Design Of A Photoelectric Transient Torque And Speed Meter, Raojibhai A. Patel

Masters Theses

"There are many situations in which it is desirable to know the speed of the shaft and the torque it is transmitting, when it is equally undesirable to make any mechanical connection to the shaft. This thesis describes the development and design of a device for measuring the torque and speed by photo-electric means. The basic principle is that a light beam parallel to the shaft may be used to pick up the desired information without adding friction to the system. The deflection of a torque tube inserted in the shaft opens or closes a set of apertures arranged in …

A Circularly Polarized Corner Reflector Antenna, Walter Ronald Koenig

Masters Theses

"Image theory is used to develop the far field and polarization equations for a ninety degree corner reflector antenna. These equations are in terms of spherical coordinates, the length of the dipole element, the distance of the dipole from the corner of the reflector, and the angle of tilt of the dipole element with the apex of the corner. The equations are simplified to give the far fields in the vertical and horizontal planes for the special case of a half-wavelength dipole. An expression to calculate the distance of the dipole from the corner necessary to give circular polarization broadside …

Design Of Non-Uniform Linear Antenna Arrays With Digitized Spacing And Amplitude Levels, Jack F. Morris

Masters Theses

"Recent developments in space exploration have shown a need for high resolution, high gain antennas. The introduction of non-uniform linear array theory has provided a means by which arrays may be designed to produce narrow main beams with fewer elements than required by uniform arrays. A general theory has not been developed, however, and the design engineer has been left with only trial-and-error methods with which to work. In this study a technique has been developed by which non-uniform antenna arrays may be synthesized to meet a given set of specifications with reasonable accuracy. The elements of the array are …

Optimum Finite Memory Nonlinear Filter, Ching-Chyoun Yang

Masters Theses

"This thesis investigates the possibility of using the Zadah theory and a machine type computer to design an optimum finite memory nonlinear filter for extraction of Poisson distributed signal pulses from a background of Gaussian noise. Basically the procedure involves the technique of solving simultaneous equations by the computer. We demonstrate that it is possible to find the limitation of the filter of class N₁ in terms of an absolute minimum mean square error. However, due to the capacity of the computer we do not actually determine the absolute minimum. Nevertheless we do show that the mean square error decreases …

Analog Simulation Of A Synchronous Machine, J. Derald Morgan

Masters Theses

"The problem presented here is a study by an analog computer simulation of a synchronous machine under balanced three phase, short-circuit conditions. The purpose is to obtain a solution that is more accurate than one obtained by approximate methods using transient and subtransient reactances as is often done. This simulation is accomplished by using an idealized synchronous machine. The equations relating voltage and currents in the machine, as well as speed and torque, are presented for simulation. The equations for the machine include the saliency of one member, as well as the effect of speed and the damper windings. A …

A Feedback Compensator Design For Linear Control Systems, Thsai-Ten Lin

Masters Theses

"The compensation process in control system engineering is indispensable. The addition of a compensator to a fixed plant can often make the system meet certain specifications easily. In this study an attempt was made to use a general purpose digital computer to design a feedback compensator. The method developed is first to determine the minimum gain of the amplifier and the number of compensator poles and zeros based on the given specifications. then free hand root-loci are plotted, with several combinations of possible compensation variables. These data are used as the open-loop transfer function from which the poles and zeros …

Circular Polarization From A Corner Reflector Antenna With Tilted Dipole Of Arbitrary Length, Ruben A. Carrizo M.

Masters Theses

"The problem consists of the development of the electric far field equations for a forty-five degree corner reflector antenna with a tilted dipole, of arbitrary length, centered at the corner bisector plane to produce circularly-polarized radiation. The far field expression was developed as a function of the spherical coordinate system variables and placed in Fortran language in order to determine the dipole locations which would produce circularly-polarized radiation. At such dipole locations the field patterns were plotted in the [theta] = [pi]/2 and [phi] = 0.0 planes. Computations were made by the IBM 1620 digital computer"--Abstract, page ii.

Linvill's Model As Applied To P-N Junction Photo-Diodes, Rudy Michael Chittenden

Masters Theses

"The problem undertaken in this study is to present a performance evaluation of Linvill's model as it pertains to the p-n junction photo-diode. The evaluation is performed by comparing the distributed mathematical solutions, the solution obtained using Linvill's lumped model, and the experimental measurement of the transient voltage rise across a photo-diode due to a unit-step pulse of light incident on the junction. Despite the absence of a suitable light source for use in the experimental measurement, it is concluded that Linvill's model provides an excellent means to determine the risetime of a photo-diode. This is provided that the photo-diode …

On Time-Optimal Second Order Discrete Control Systems, Chao-Tai Li

Masters Theses

"The time optimal control problem in unforced discrete systems is studied in this thesis. Comparison is made between the discrete and the continuous control systems by means of minimum time isochrones. concerning optimal time, it is shown that using the discrete control system will take at most one more sampling period of time to go to equilibrium. An investigation is also made for the case when the time constant of the physical plant, G(s), and the control model are different. In such a case, an optimal trajectory can not be obtained. An adaptive process is proposed to adjust the model …

An Evaluation Of Demonstrations On Inductor Theory, Boyd Warner Wasson

Dissertations and Theses @ UNI

The writer sought an improved approach for teaching theory of electronics to high school students. This approach was intended to require less expense and time needed to provide classroom instruction on electrical theory.

The purpose of this study were to:

(1) Prepare a number of demonstrations to illustrate phenomena associated with coils or inductors and their use in practical electronics.

(2) Prepare equipment and gather parts needed to perform demonstrations. Ease of construction and economy were important considerations.

(3) Evaluate the effectiveness of the demonstrations on student comprehension and the ability to apply information taught.

Stability Determination By Liapunov's Method In Nonlinear Control Systems, Neng-Chung Liao

Masters Theses

"An introduction to Liapunov's second method as it applies to control system stability is presented in this work. Main theorems and definitions of Liapunov's method are treated. In particular, Lur'e's method and Szego's method for testing the stability of a nonlinear system are presented, and several examples are used to illustrate these procedures"--Abstract, page ii.

Analog Computer Study Of Unequally Spaced Antenna Arrays, Fred M. Dickey

Masters Theses

"The problem undertaken in this thesis was to study the basic properties of unequally spaced antenna arrays. The study was done on a trial and error basis by simulating the expression for the far field pattern of a general array on an analog computer. Many patterns were obtained from the analog computer for the purpose of comparison. The patterns of two spacing schemes that are typical of unequally spaced arrays are presented for the purpose of illustration"--Abstract, page ii.

Transient Gamma Radiation Effects On Resistors, Harold T. Cates

Electrical and Computer Engineering ETDs

If a resistor in a circuit is exposed to a transient gamma radiation pulse, the condition of the circuit will be modified by passing from its steady state condition before radiation to a state of excitation that will depend upon the intensity and duration of the radiation pulse. When the radiation pulse is over, the circuit will then relax to its previous condition of equilibrium within a characteristic time constant.

When energetic radiation, such as gamma radiation, charged particles, or neutrons, strikes matter, it causes several effects which alter the properties of the target material. Some of the effects that …

Antennas In Or At The Surface Of A Conducting Medium At Vlf, George R. Swain

Electrical and Computer Engineering ETDs

To meet the requirements of a number of military operations and to facilitate some types of geophysical exploration, it is necessary to communicate between points beneath or at the surface of the earth or of the ocean. This need has led to the investigation of antennas for use in or at the surface of conducting media. The purpose of this paper is to briefly survey the previous work on such antennas, to extend the concepts of effective length and other merit factors to antennas in or near a conducting medium, and to analyze the electrical behavior of the toroid and …

An Experimental Determination Of Ultrasonic Wave Velocities In Plastics As Functions Of Temperature, Ned D. Arnold

Electrical and Computer Engineering ETDs

This thesis reports the results of an experimental investigation into the effects of temperature on the velocity of ultrasonic longitudinal acoustic waves through various plastics.

The Driving-Point Impedance Of An Electrically Short Cylindrical Antenna In The Ionosphere, William E. Blair

Electrical and Computer Engineering ETDs

1.0 Since the advent of satellites, there has been con­siderable interest in both military and peacetime uses of satellites as research instruments, communication relays, and transportation vehicles. In most cases, it is necessary to communicate with the satellites for purposes of trans­mitting and receiving information.

A Method Of Process Identification Of Certain Linear Control Systems, Eugene A. Aronson

Electrical and Computer Engineering ETDs

No abstract provided.

A Study Of Electro-Magnetic Wave Propagation In Inhomogeneous Media, Thomas N. C. Wang

Electrical and Computer Engineering ETDs

The central problem of this work will be the development of several approximation methods and the application thereof to the solution of second order linear differential equations which arise in connection with the propagation of electromagnetic radiation in inhomogeneous media. Chapter I is an introduction to the problem. Maxwell’s equations are written down and it is assumed that both σ, the conductivity, and ɛ, the permittivity, are scalar functions or position. Often the above function characterizing some or the properties of matter vary in physical situations. For example, in waveguides, there may be inserted layers of dielectric material along the …

The Multi-Terminal Hall Generator, Sang S. Pak

Electrical and Computer Engineering ETDs

This thesis describes a study undertaken to maximize the Hall generator efficiency. A mathematical solution is obtained for a multi-terminal Hall generator, and an analytical technique is developed for determining the optimum values of parameters to maximize the generator efficiency. An equivalent circuit is developed for an N output-terminal Hall generator, and the efficiency expression is obtained as a function of sample dimension, conductivity and Hall coefficient of the material, and magnetic field strength. Some of the results have been checked experimentally with indium antimonide and fields up to 21.5 kilogauss. An efficiency of 40% was obtained experimentally for a …

A Kerr Cell System For Measuring The Amplitude Of High-Voltage Nonrecurring Pulses, Donald C. Wunsch

Electrical and Computer Engineering ETDs

There are at present several conventional techniques and systems to measure the peak amplitude of high-voltage pulses. Three of the prin­cipal techniques are:

1. Potential dividers in conjunction with some type of low-voltage recording system.

2. High-voltage oscilloscopes with low sensitivity.

3. Sphere gaps with predetermined breakover voltages.

Potential dividers of many types have been developed. These include resistive voltage dividers, capacitive voltage dividers, and combination resistive and capacitive dividers. The different designs have usually been developed to eliminate some error in measurement. Different types of resistive windings have been designed to minimize self-inductance. Shields have been designed to reduce …

Predicting Current Gain Degradation In Npn Silicon Transistors After Irradiation By High-Energy Neutrons, Jerry A. Hood

Electrical and Computer Engineering ETDs

The damage discussed in this report is permanent and remains after all transient ionization has decayed. The damage which predominantly affects the electrical characteristics of a transistor is the creation of "vacancies" and "interstitials" in the lattice structure. These defects are created when an atom is knocked from its position and leaves a vacancy in the lattice. The atom comes to rest in a position out of the lattice structure and is known as interstitial. These atoms are knocked from their positions by the irradiating neutrons or by an interstitial traveling through the crystal. These defects occur in localized clusters …

The Design Criteria Of A Phoswich Transducer., Richard L. Crawford

Electrical and Computer Engineering ETDs

This dissertation is an experimental and theoretical treatise on the design criteria of a phoswich transducer. The major emphasis is on the application in a gamma-ray spectrometer. The conversion efficiency, gamma-ray cross sections, response to charged particles, luminescence decay time, spectral response and physical qualities are discussed, in considerable detail, in making the optimum choices for the inorganic crystal and the organic phosphor which will act as the charged particle anticoincident shield. The effect of the thickness of the anticoincident shield on resolution, the percentage of gamma-rays absorbed, the percentage of gamma-rays that are atten­uated in energy and the lower …

Electric Fields From Airborne Vertical And Horizontal Dipoles At Very-Low Frequencies, A. H. Garry Gibson

Electrical and Computer Engineering ETDs

A gap exists in present-day knowledge of the electric fields in the earth which are radiated from elevated antenna structures in the earth-air-ionosphere waveguide. It is the purpose of this paper to present a method of estimating the electric field at the earth-air boundary, caused by elevated antenna structures, and to show the existence of new phenomena that may lead to an improved design of communication systems.

On Optimum Receiver Using Decision Theory, Philip T. Tai

Masters Theses

“In recent years communication engineers have given increased attention to the study of communication through random media. The name random is used to describe a medium the properties of which are stated only in a statistical sense. For example the impulsive response of a certain medium may only be known as one of an ensemble of possible impulsive responses; the particular member of interest being drawn up according to some statistical rule. In other words there exists some "uncertainty" concerning the characteristic description of the medium. Significant work on these problems has been done by Price and Turin. Related work …

An Analysis Of The Simulated Inductande Obtained From Forward Biased Semiconductor Diodes., Everett Harold Vannoy

Masters Theses

"The problem undertaken in this thesis is to study the simulated inductance observed in forward-biased abrupt junction p-n diodes with a highly doped p region and a nearly intrinsic n region and show that it is due to conductivity modulation. Unlike other analyses of this phenomenon, a voltage step is applied to the diode in such a direction as to forward bias it and the behavior of the injected minority carriers are observed. By comparing the resultant current through the diode to the relationship predicted by the equivalent circuit of the diode, an expression is obtained for the simulated inductance. …

The Resolution Of Two Known Signals In White Gaussian Noise., Peter Cheng-Fang Wang

Masters Theses

"The problem of resolving two signals F1(t) and F2(t) in white Gaussian noise n(t) is treated here as a problem in statistical decision theory. We assume a situation in which one of two similar signals is present and an observer is asked to make a decision concerning which of the signals is present with a tolerable probability of error. The observer is allowed to use the best system which he can design for this particular purpose. Of course, this observation will be disturbed by noise and therefore, the observer is led to ambiguous selections. It is apparent that the optimum …

Optimum Zero-Memory Nonlinear Filter, Benjamin Shaw-Hu Wang

Masters Theses

“The purpose of this report is to review the basic work described by Zadeh insofar as systems of class N₁ are concerned and to apply his general results to a specific problem in which a non-linear filter is mandatory simply because the linear filter is essentially ineffective. The ineffectiveness stems from the fact that the autocorrelation function of the signal plus the noise has essentially the same variational character as the signal alone. Therefore, the transfer function of the linear filter turns out to be simply a constant. Thus, the output of the linear filter is just an attenuated …

Radiation Characteristics Of A U-Slot Antenna., Richard Paul Brueggemann

Masters Theses

"The radiation equations for a simple rectangular slot antenna are derived as a function of the field distribution in the slot. The electric field distribution in the slot is then formulated as a function of the aperture dimensions. The U-shaped slot antenna is described as an extension of the rectangular slot theory and the actual field is measured in the slot for comparison.

The far field equations a.re derived for the U-slot antenna similar to those for the rectangular slot antenna and are evaluated using the formulated distributions in the slot for antennas of two different electrical sizes. The equations …

Synthesis Of Unity-Gain Rc Networks From Second Degree Transfer Functions., Ronald L. Mcnally

Masters Theses

"A synthesis procedure is presented which realizes second order open circuit transfer functions. This procedure is developed using parallel networks. The transfer functions for each parallel network are obtained by use of separation parameters. Two constraints are used in the development: first, the realized network must be an RC network; second, the desired multiplicative gain constant must be realized. With these constaints a parameter space is developed which aids in the selection of the proper parallel networks to be combined. Necessary and sufficient conditions are developed which are used to test the transfer functions. The realization simply consists of the …

Compensator Design For Unity Feedback Systems Using An Analytical Method, Chang-Yu Wu

Masters Theses

“In control systems engineering it is frequently necessary to compensate a fixed plant whose transfer function cannot be changed. Usually the characteristics of the resulting system are established in terms of steady-state and transient performance specifications. Generally it is necessary to insert a compensator which insures stability as well as satisfies the specifications.

In this thesis an analytical method is developed to determine the transfer function of the compensator in order to satisfy the following set of specifications. The fixed system is assumed to contain one non-linearity, saturation. The input to the saturable device is constrained in a statistical …