Electrical and Electronics Commons^™

Design Of A Yig-Tuned Oscillator, Tien Liang Jin

Theses

A technique for designing YIG (yttrium-iron garnet) tuned transistor oscillators, tunable over the range of frequencies from 500 to 950 MHZ, is presented. The approach taken differs appreciably from that used in the design of conventional LC-tuned oscillators. One major difference is that the YIG tuning mechanism is electrically controlled. The YIG tuning element is treated as a single unit and is not resolved into an equivalent LC circuit. Instead, a direct method using reflection coefficients measured at network terminals to characterize various design stages is applied. The transistor is also characterized by reflection and transmission coefficients, i.e., S-parameters. Thus …

Steady State And Dynamic Performance Of Anisotropic Reluctance Motor, S. Chandrasekhara Rao

Theses

The paper deals with a special type of reluctance motor called Anisotropic rotor reluctance motor. As the name implies, advantage is taken of the internal anisotropy of the rotor magnetic structure. Axially laminated grain oriented silicon steel is used in the rotor. This unconventional configuration of assembly of rotor laminations results in a high ratio of direct axis to quadrature axis reluctance. Compared to the conventional reluctance motor, pull out torque of more than three times and a power factor as high as in an induction motor is obtained. Several motors of ratings up to 60 HP. were built and …

Correlation Of Drain Breakdown With Excess Noise And Other Surface-Related Phenomena In Enhancement Mosfets, Jerry J. Rij

Theses

An investigation of semiconductor surface-related phenomena has been undertaken to correlate 1/F noise with drain breakdown in P-channel enhancement MOSFET's. Increases in the intensity of drain current fluctuations at 10Hz and at 1KHz, particularly at the higher frequency, was observed following accelerated life-testing for threshold voltage drift. It was also concluded that mobile ions near the oxide-semiconductor interface produce a sharp increase in fast trapping centers. It was also found that 1/F noise intensity consistently peaked at the threshold of drain breakdown and that it steadily decreased with further increases in drain current. Of all the transistors tested, those with …

Correlation Of 1/F Noise With Threshold Drift In Mosfet's, John Peter Rooney

Theses

A brief review of the fundamentals of MOSFET's is given. A correlation between threshold drift and surface states is made, with a following correlation between surface states and 1/f noise. It therefore follows that MOSFET's with a high 1/f noise level will drift more than those with a low level of 1/f noise. Experiments were carried out to show this effect, but no clear cut conclusions can be drawn from the experimental work.

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.

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 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 …

The Rimo Filter, Richard Thomas Modafferi

Theses

Up to the present time, there has existed no general method for obtaining the pole locations of minimum-phase constant time delay filters of desired selectivity. Since constant time delay filters are necessary for low distortion FM transmission, and minimum-phase filters are easy to construct and align, a general method for locating the poles of minimum-phase constant time delay filters would be of considerable importance. Presented in this paper is a procedure for locating the poles of minimum-phase constant time delay filters of desired selectivity, using a FORTRAN digital computer program. Two experimental FM receivers were built to test. the new …

The Effect Of Velocity On The Electrical Conductivity Of Blood, Judea Pearl

Theses

Although the change in the conductance of blood resulting from changes in its velocity has been noted by several investigators working with electrical impedance techniques, this parameter of measurement has heretofore not been investigated from the viewpoint of practical application to blood flow measurement.

In certain regions of the body such as the tooth pulp and the cranial cavity, the volume of the contained blood cannot fluctuate during a cardiac cycle because of the rigid wall of the chamber. Therefore, impedance pulses which have been obtained in studies on the tooth pulp, must be attributed to the rhythmical fluctuation of …

The Incandescent Lamp, E. F. Tenbroeke

Theses

A brief history of the development of the incandescent lamp.