published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

The growing demand of portable electronic equipment and system-on-a-chip has been pushing the industry to design circuits with very low power supply voltage and low power consumption. The Hard Disk drive industry is looking for developments in the read channel chip to push the data rates to higher speed, along with a low voltage and low cost solution. Read channel requires high-speed linear phase filters to meet these objectives. The primary objective of this project is to design, layout, and characterize a 4th-order continuous-time equiripple linear phase filter with automatic tuning system. The main requirements for design are high speed, low group delay variations, good linearity and power efficiency. This filter features wide cut-off frequency 500MHz, which is far beyond the current state-of-the-art. The linear phase filter is based on Gm-C biquadratics. Higher speed has been achieved by minimizing the parasitics and a complementary input stage OTA. A common mode feedback (CMFB), which ensures stability at such high frequencies, has also been designed. The inaccuracies of the filter are compensated by using a simple automatic tuning system. The design is fabricated in 0.35 um TSMC CMOS process technology. The design was simulated in Cadence using SPICE models provided by MOSIS for the 0.35 um TSMC process in the presence of parasitic capacitance and transistor non-idealities. Cut-off frequency of 500 MHz was achieved along with a 9% variation in the group delay.

The aim of this research is to study the work function (Фm) tuning of the HfxSiyNz metal films through the incorporation of nitrogen. The Hf and the Si targets were co-sputtered in nitrogen (N2) and argon (Ar) plasma at 12mTorr. The gas flow ratio, RN = N2/ (N2+Ar), was adjusted to vary the nitrogen concentration in HfSiN films. The work function (Фm) of HfSiN gate extracted from the capacitance-voltage (CV) and the internal photoemission (IPE) measurements was found to decrease (from ~ 4.64eV to ~ 4.42eV) for increasing gas flow ratios (from 10% to 30%). X-ray photoelectron spectroscopy (XPS) was used for material characterization. During XPS analysis, the nitrogen (N 1s) peak intensity was observed to increase with increasing gas flow ratios. The results indicate that adjusting the nitrogen concentration in HfSiN films can be used to tune the HfSiN gate work function over ~ 0.2 eV tuning window.

The aim of this research is to study the work function (Фm) tuning of the HfxSiyNz metal films through the incorporation of nitrogen. The Hf and the Si targets were co-sputtered in nitrogen (N2) and argon (Ar) plasma at 12mTorr. The gas flow ratio, RN = N2/ (N2+Ar), was adjusted to vary the nitrogen concentration in HfSiN films. The work function (Фm) of HfSiN gate extracted from the capacitance-voltage (CV) and the internal photoemission (IPE) measurements was found to decrease (from ~ 4.64eV to ~ 4.42eV) for increasing gas flow ratios (from 10% to 30%). X-ray photoelectron spectroscopy (XPS) was used for material characterization. During XPS analysis, the nitrogen (N 1s) peak intensity was observed to increase with increasing gas flow ratios. The results indicate that adjusting the nitrogen concentration in HfSiN films can be used to tune the HfSiN gate work function over ~ 0.2 eV tuning window.

The purpose of this study was to make a comprehensive examination of factors concerning the intonation and methods of tuning the wind instruments in the university wind ensemble. The study concerned itself with the following issues:1. Temperaments and tunings used in tuning the university wind ensemble2. Pitch discrimination of the individual ensemble member3. Collective intonation variances of the instruments of the university wind ensemble, and how may they be corrected4. Methods of tuning the university wind ensembleThe study assumed that the musicians in the university wind ensemble are selected upperclass and graduate students auditioned from the university band program, who possess professional or near professional playing ability.Furthermore, the musicians have been exposed to university theory courses, which include melodic and harmonic ear training. The instruments played in the ensemble are of professional quality, and the environments in which the wind ensemble performs are the rehearsal hall and the concert stage.Information for this study was obtained from essentially two sources. A survey of literature pertaining to tuning systems and temperaments, the pitch discrimination ability of the individual, intonation variances of musical instruments in the wind ensemble and tuning methodology provided the first source of information.The expert testimony of eminent university wind ensemble directors was the second source of information. The directors interviewed for this purpose were John Paynter of Northwestern University, Mark Hindsley (Director Emeritus) of the University of Illinois, Harry Begian of the University of Illinois, Mark Kelly of Bowling Green State University and Frederick Ebbs of Indiana University. Each director was asked to read the first part of the study and subsequently to comment on how he felt the information applied to the tuning of the university wind ensemble. A set of interview topics was used to guide the wind ensemble directors over the given subject matter. Their answers were tape recorded and transcribed for the study. Conclusions were then drawn from these two sources.The findings and conclusions of this study are as follows:1. A survey of literature revealed that theories concerning the overall tuning system of the wind ensemble vary. Furthermore, university wind ensemble directors interviewed in this study were not in agreement as to what intonation system the wind ensemble should utilize. This study was therefore inconclusive in identifying a single method of tuning the wind ensemble that is universally accepted.2. Different components of musical sound were found to affect the pitch discrimination ability of the individual. The individual's perception of intonation was found to be influenced by the range of pitch, phenomenon of beats, vibrato, duration of musical tones and timbre. The influence of first order combination tones and increased volume on pitch was found to be a controversial issue in both written and interviewed sources of intonation.3. The wind ensemble is composed of a large number of wind instruments capable of emitting a wide range of musical pitches, which in turn represent a great number of possible intonation variances and deficiencies. Both conductor and performer must have a comprehensive knowledge of these-problems and their remedies in order to attain uniform ensemble intonation.4. Tuning practices do vary according to the ensemble's needs and the director's rehearsal procedure. However, proper attention must be given to warm-up procedure, level of pitch, selection of reference pitch or pitches, method of relaying the pitch to the ensemble and methods of correcting faulty intonation to insure consistent intonation within the ensemble.

Detailed discussion of tuning the classical guitar within the context of equal temperament's development. Alternative models for tuning systems are discussed along with accurate and practical guidelines on how to tune the conventional classical guitar using equal temperament.

Detailed discussion of tuning the classical guitar within the context of equal temperament's development. Alternative models for tuning systems are discussed along with accurate and practical guidelines on how to tune the conventional classical guitar using equal temperament.

Thesis (M.Mus.T.)--University of Tulsa, 1990. / Bibliography: leaves 153-159.

Thesis (Ph. D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1987. / Includes bibliographical references (leaves 329-348).

Thesis (Ph.D.)--Virginia Commonwealth University, 2010. / Prepared for: Dept. of Electrical Engineering. Title from title-page of electronic thesis. Bibliography: leaves 177-185.