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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Creators: Peterson, Cory
- Member of: ASU Electronic Theses and Dissertations
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
This thesis analyzes how several well-known biographies of popular nineteenth-century British literary figures overturned and upset the usual heroic literary biographies that typified the genre during the Victorian era. Popular public opinion in the nineteenth century was that literary biographies existed as moral guideposts--designed to instruct and edify readers. Richard D. Altick's theory of biographical conventions of reticence--which contends that ultimately literary biographies were committed to establishing or preserving an idealized image of the author--is utilized to explore the nuances of how certain radical biographies in which the biographer is forthright about the subject's private life displeased and disturbed the public. In order to illustrate this study's central argument, several literary biographies that were considered among the most radical of the late Victorian period--John Forster's Life of Charles Dickens, James Anthony Froude's Life of Carlyle, Mathilde Blind's George Eliot, and John Cordy Jeaffreson's The Real Shelley--are analyzed as case studies. These biographies of writers' lives made heroic figures appear human, vulnerable, petty, et cetera by exposing private life matters in a public biography--something that was not done in an age that called for discreet biographies of its literary icons. Victorian periodicals such as magazines and newspapers assist in ascertaining just how the British public reacted to these biographies, and the ramifications they possessed for worshipping literary idols. Additionally explored are the implications that candid literary biographies had for Victorian author-worship and the role of literature, authors, and biography in British society. This study concludes with a discussion of the implications that these candid literary biographies had into the early twentieth century with the publication of Lytton Strachey's "deflated" biography, Eminent Victorians, published in 1918, and summarizes overall findings and conclusions.
ContributorsLeTourneur-Johnson, Jessica Ann (Author) / Warren-Findley, Jannelle (Thesis advisor) / Codell, Julie F. (Committee member) / Szuter, Christine (Committee member) / Arizona State University (Publisher)
Created2011
Description
Tobias Smollett was an eighteenth-century surgeon, writer, novelist, and editor. He was a Scotsman who sought his fortune in south Briton. Throughout his life and career he experienced many of the cultural and political influences that helped to shape the British identity. His youth as a Lowland Scot, student and apprentice, and naval surgeon enabled him to embrace this new identity. His involvement in nearly every aspect of the publishing process in London enabled him to shape, define, and encourage this identity. His legacy, through his works and his life story, illustrates the different ways in which the United Kingdom and its inhabitants have been perceived throughout the centuries. As a prominent man of his time and an enduring literary figure to this day, Smollett offers an ideal prism through which to view the formation of the British identity.
ContributorsKeough, Megan (Author) / Warnicke, Retha (Thesis advisor) / Szuter, Christine (Committee member) / Wright, Kent (Committee member) / Arizona State University (Publisher)
Created2011
Description
The Victorian era was the age of museum development in the United States. In the wake of these institutions, another important figure of the nineteenth century emerged--the flâneur. The flâneur represents the city, and provided new mechanisms of seeing to the public. The flâneur taught citizens how to gaze with a panoptic eye. The increasing importance of cultural institutions contributed to a new means of presenting power and interacting with the viewing public. Tony Bennett's exhibitionary complex theory, argues that nineteenth-century museums were institutions of power that educated, civilized, and through surveillance, encourage self-regulation of crowds. The flâneur's presence in the nineteenth century informed the public about modes of seeing and self-regulation--which in turn helped establish Bennett's theory inside the museum. The popular writing and literature of the time provides an opportunity to examine the extent of the exhibitionary complex and the flâneur. One of the most prominent nineteenth-century authors, Henry James, not only utilizes museums in his work, but he often uses them in just the manner Bennett puts forth in his theory. This is significant because the ideas about museums in James's work shaped the minds of an expanding literary public in the United States, and further educated, civilized, and regulated readers. James also represents the flâneur in his writing, which speaks to broader cultural implications of the both exhibitionary complex on the outside world, and the effects of broader cultural influences on the museum. Beyond the impact of James's work, in the late nineteenth century American culture increasingly became centered around the printed word. The central position of books in American culture at the end of the nineteenth century allowed books and libraries to appropriate the exhibitionary complex and become tools of power in their own right. The book and the library relate to the museum as part of a larger cultural environment, which emerged as a result of modernity and a response to the ever-changing nineteenth-century world.
ContributorsHarrison, Leah Gibbons (Author) / Szuter, Christine (Thesis advisor) / Warren-Findley, Jannelle (Committee member) / Toon, Richard (Committee member) / Arizona State University (Publisher)
Created2011
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015
Description
In the preface to his 1852 Dictionary of Domestic Medicine and Household Surgery, Spencer Thompson wrote: "But health will fail, either in old or young, and accidents will happen, in spite of the most careful precaution." With this concise statement, Thompson summarized the universal human desire to combat illness, injury, and hurt with action and knowledge. The more efficient ability to spread ideas and technology in nineteenth-century Britain led to increased production and use of home remedy books. Although women traditionally represented the agents of remedy and care within the domestic sphere (centuries prior to the nineteenth century), a struggle between the supposed inherent nurturing capabilities of womanhood and the professional medical realm occurred within the rhetoric of the home remedy genre during this period. Cultural mores allowed and pushed women to take up duties of nursing in the home, regardless of advice given by male physicians like Thomas John Graham, W.B. Kesteven, and Ralph Gooding. Despite remedy book physician-authors' attempts to dictate appropriate medical care in the home through the writing of home remedy books, British women read, interpreted, and used home remedy books in ways that undermined medical control.
ContributorsJacobson, Emily (Author) / Green, Monica (Thesis advisor) / Szuter, Christine (Thesis advisor) / Warren-Findley, Jannelle (Committee member) / Arizona State University (Publisher)
Created2011