This thesis describes compensation techniques for cascaded delta-sigma A/D converters (ADCs) and high-performance switched-capacitor (SC) circuits. Various correlated-double-sampling (CDS) techniques are presented to reduce the effects of the nonidealities, such as clock feedthrough, charge injection, opamp input-referred noise and offset, and finite opamp gain, in SC circuits. A CDS technique for the compensation of opamp input-referred offset and clock-feedthrough effect is examined and improved to achieve continuous operation. Experimental results show that after the compensation, the SC integrator's output signal swing is greatly increased. The effects of the analog circuitry nonidealities in delta-sigma ADCs are also analyzed. The analysis shows that the nonidealities in cascaded delta-sigma ADCs cause noise leakage, which limits the overall performance of the cascaded modulators. In order to reduce the noise leakage, a novel adaptive compensation technique is proposed. To verify the effectiveness of the proposed compensation techniques, a prototype 2-0 cascaded modulator was designed. Its first stage, a second-order delta-sigma modulator with test signal input circuit, was designed and fabricated in 1.2 ��m CMOS technology. The measurement results show that the noise leakage is reduced effectively by the compensation, and the performance of the cascaded delta-sigma modulator is greatly improved. / Graduation date: 1999

Pulse Width Modulation (PWM) has been used extensively for motor control, DC-AC converters, DC-DC converters and in audio applications. The conventional method of generating a pulse width modulated signal involves generating an accurate sawtooth or triangle wave using analog circuits. In CMOS, being analog circuit intensive puts extra constraints on the fabrication process used for manufacture, thus requiring a higher cost than digital CMOS. Delta-Sigma Modulation on the other hand is analog intensive, but requires only quality capacitor matching, which can be obtained with current digital CMOS processes. This thesis describes a method to generate a digital PWM with pulse dithering using a Delta-Sigma modulator. The Delta-Sigma modulator provides accuracy and allows the circuit to be implemented in a digital CMOS process, while the pulse dithering in the PWM spreads out harmonic noise generated from the PWM fundamental frequency. / Graduation date: 1998

Past experiences have relevant truths for the present. An uncommon work and living situation from this writer's undergraduate days shows how prejudice and stereotype can be subtly arranged, and participated in, by the nature of his surroundings. This thesis explores, through the combination of related past events with an interspersed imperative address to the reader, the ways in which the writer was stereotyped by those he served because of the limited nature of their interactions. This writer, in turn, formed prejudices against those for whom he worked. The imperative addresses to the reader advise one not to accept without question simple categories and judgments for people based solely upon circumstance and situation. / Graduation date: 1996

The main purpose of this thesis is to research High-Order Sigma-Delta Analog-to-Digital converter for precision measurement, a PI compensator and a third-order Sigma-Delta modulator has been proposed based on a second-order Sigma-Delta modulator. In accordance with the analysis result of frequency domain and time domain of system, we use third-order model because of better response with auxiliary software to simulate and implement the system, then measure modulator output variance for input variation. This converter circuit demonstrates that it can achieve the requirements of precision and linearity which the measure instrument demands.

For the fractional-N frequency synthesizers using delta-sigma modulation (DSM) techniques, higher PLL bandwidth is highly desirable in order to achieve faster settling time. As the PLL bandwidth is increased, more quantization noises pass through the PLL so that the output phase noise performance is degraded. There is a tradeoff between phase-noise performance and PLL bandwidth. To improve the problem, the thesis studies the quantization noise cancellation technique. With this technique, the PLL bandwidth can be increased without the cost of degrading phase-noise performance. With the help of Agilent EEsof¡¦s ADS, the phase-noise performance of the studied fractional-N frequency synthesizers can be predicted. For demonstration, this research implements a 2.6 GHz fractional-N frequency synthesizer hybrid module, and compares the measured phase noises with and without the technique under considering various combinations of MASH DSM orders and PLL bandwidth. Another demonstration of this thesis is to design a PLL IC using TSMC 0.18 £gm CMOS process, and make a discussion on the testing performance of the PLL IC.

Tissue-equivalent proportional counters are frequently used to measure dose and dose equivalent in cosmic radiation fields that include high-Z, high-energy (HZE) particles. The fact that particles with different stopping powers can produce the same energy deposition in the same detector means that the measure of lineal energy cannot provide enough information to evaluate the equivalent dose due to HZE particles. To characterize incident particles by mass and velocity, a multiple-detector system composed of three tissue-equivalent proportional counters simulating different size tissue volumes was proposed to be built. This system took advantage of the well-known fact that lineal energy (y) of a HZE particle depends on the site size, as well as the particle mass and energy. Monte Carlo calculations were used to evaluate lineal energy, using GEANT4, in grid-walled (wall-less) proportional counters with simulated unit density site diameter of 0.1, 0.5 and 2.5 micrometers in a uniform HZE particle field. Uniform beams of 1000 MeV/n and 100 MeV/n 56Fe26+, 28Si14+, 16O8+, 12C6+, 4He2+ ions and proton particles bombarding the detectors were simulated. The results of the calculations were used to determine how much additional information about particle charge and velocity could be obtained from such a detector system. Comparison of simulation results with those of walled detectors was included in the study to illustrate the wall effect. The results shows that the detector system is capable of characterizing HZE particles in a mixed unknown field based on the lineal energy spectra as well as the calculated mean lineal energy. This suggests that it may be practical to use such a system to measure the average particle velocity of HZE particles in space. The parameters used in the simulation are also good references for detector construction. There is only limited experimental data for lineal energy resulting from a large uniform field of HZE particles incident on a wall-less detector. However, the Monte Carlo results are consistent with the experimental data available.

The hepatitis delta virus (HDV), composed of ~1,700nt, is the smallest circular RNA pathogen known to infect humans. Understanding the mode of replication of HDV implies on investigating the host proteins that bind to its genome. The polypyrimidine tract-binding protein-associated splicing factor (PSF), an HDV interacting protein, was found to interact with the carboxy terminal domain (CTD) of RNA polymerase II (RNAPII), and to facilitate the interaction of RNA transcripts with the CTD of RNAPII. Both PSF and RNAPII were found to interact with both polarities of the terminal stem loop domains of HDV RNA, which possess RNA promoter activity in vitro. Furthermore, PSF and RNAPII were found to simultaneously interact with HDV RNA in vitro. Together, the above experiments suggest that PSF acts as a transcription factor during HDV RNA replication by interacting with both the CTD of RNAPII and HDV RNA simultaneously. PSF knockdown experiments were performed to indicate that PSF is required for HDV RNA accumulation. Mutagenesis experiments of PSF revealed that HDV RNA accumulation might require the N terminal domain, and the RNA recognition motifs RRM1 and RRM2. I propose that the RRM1 and RRM2 domains might interact with HDV RNA, while the N-terminal domain might interact with the CTD of RNAPII for HDV RNA accumulation. Together, the above experiments provide a better understanding of how an RNA promoter might be recognized by RNAPII.

In present day, digital signal processing (DSP) is a popular technology and widely used in many fields. There have increasing number of applications that need high resolution converters. Therefore, analog-to-digital converters play a major role in DSP, and a well-performed ADC will enhance the performance of a certain system. Different types of ADCs are available for various functions. Delta-sigma  converters are famous for high resolution. Dynamic parameters can be used to judge the performance of an ADC, this paper will focus on the critical parameters of spectrum analysis, which contains Signal-to-Noise-and-Distortion Ratio (SINAD), Effective Number of Bits (ENOB) and Spurious-free Dynamic Range (SFDR). The theory and test method of these critical parameters are proposed in this paper using the Evaluation Module and Matlab. The results we acquired from the Evaluation Module are SINAD=86.15dB, SFDR=109.2dB, ENOB=14.177bits; and the results we calculated from MATLAB are: SINAD=86.14dB, SFDR=108.8dB, ENOB=14bits.

A measurement of the azimuthal decorrelation in di-jet events in proton-proton collisions at $\sqrt{s}= 7\,$TeV is presented. Using $19.6\,$nb$^{-1}$ of data collected in the ATLAS detector this measurement uses the angle ($\Delta\phi$) in the transverse plane between the two leading $p_T$ jets to measure the normalized differential cross section $\frac{1}{\sigma_{tot}}\frac{d\sigma}{d(\Delta\phi)}$. An unfolding correction is a applied to give a jet-level result. The unfolded spectrum is compared to the predictions of two Monte Carlo event generators: Pythia and Herwig++.

A measurement of the azimuthal decorrelation in di-jet events in proton-proton collisions at $\sqrt{s}= 7\,$TeV is presented. Using $19.6\,$nb$^{-1}$ of data collected in the ATLAS detector this measurement uses the angle ($\Delta\phi$) in the transverse plane between the two leading $p_T$ jets to measure the normalized differential cross section $\frac{1}{\sigma_{tot}}\frac{d\sigma}{d(\Delta\phi)}$. An unfolding correction is a applied to give a jet-level result. The unfolded spectrum is compared to the predictions of two Monte Carlo event generators: Pythia and Herwig++.