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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
In the university setting, when a person wants to conduct research that deals with human subjects, they are required to receive the approval of their Institutional Review Board (IRB). This process takes place to ensure the proposed research is ethical and poses minimal risks to the willing subject. In Indian Country, there is a growing trend where American Indian nations are taking control over regulating research that is conducted within their jurisdictional boundaries.
In my thesis, I discuss the historical background that has led to the IRBs academics are familiar within universities they see today. In addition, I discuss the body of literature that addresses IRBs, human subjects, and the debate on which research should or should not be regulated by universities. I will then, critically analyze the established research protocols that exist in Arizona American Indian tribes. I use Darrell Posey's (1996) idea of Community Controlled Research (CCR) as the framework for my analysis. CCR dictates the people of the community decide the ways in which research is conducted. The purpose of my research is to create recommendations that will assist and inform tribes how to either, strengthen their existing protocols, or create a research protocol that will promotes Community Controlled Research.
In my thesis, I discuss the historical background that has led to the IRBs academics are familiar within universities they see today. In addition, I discuss the body of literature that addresses IRBs, human subjects, and the debate on which research should or should not be regulated by universities. I will then, critically analyze the established research protocols that exist in Arizona American Indian tribes. I use Darrell Posey's (1996) idea of Community Controlled Research (CCR) as the framework for my analysis. CCR dictates the people of the community decide the ways in which research is conducted. The purpose of my research is to create recommendations that will assist and inform tribes how to either, strengthen their existing protocols, or create a research protocol that will promotes Community Controlled Research.
ContributorsTom, Naomi (Author) / Vicenti Carpio, Myla (Thesis advisor) / Killsback, Leo (Committee member) / Tippeconnic, John (Committee member) / Arizona State University (Publisher)
Created2015
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
Through the lens of a Jewish family in the early 20th century, histories of resilience, rescue, and resistance are shown. The Loewys were a Jewish family who migrated from Poland to Germany then France and ending up in the United States following World War II. In their travels they experienced many of which other Jewish experiences were, while also differentiating from the overall story. The family also experienced life as refugees and interns during the Holocaust. Arrested in Vichy following the Armistice between Germany and France, the Loewys were later granted their freedom which they used to help free others from the camp. One of the few stories of Jews rescuing Jews, the family began its life as resistors to the Vichy and German occupation. Participating in both passive and active resistance from 1940-1944, they witnessed the highs and lows of this new life. The end of the war saw the family make it to the United States beginning their next chapter as survivors of the Holocaust and the war. With the use of primary source material provided by the Loewys, along with scholarly work about the different periods, the story of the Loewys is one of resilience in the face of mounting adversity, rescuing of internes from camps, and resistance against an occupational force that furthers the research of the Jewish experience in the early 20th century.
ContributorsVance, Marc (Author) / Benkert, Volker (Thesis advisor) / Cichopek-Garaja, Anna (Committee member) / LePore, Paul (Committee member) / Arizona State University (Publisher)
Created2020
Description
In theory, all that are involved in same-sex practices in Islam based on thecommon and mainstream interpretation of the story of the people of Lut are treated the same. In reality, however, and in the Arab world today, the penetrated and penetrator are not equally abnormal and deviant. Although Western activism involved in gay rights in the Middle East and local communities in several countries who call themselves Mujtamaa Al Meem, the community of the letter Meem, which is a localization of the term LGBTQA+ community, are advocating for gay rights for all Middle Eastern/Arab/Muslim “gay men” whatever role they play in those practices. The local culture of those societies does not do the same, nor do they believe in their normality. By looking at different interpretations of religious scripture, role of Westernization in local “gayness” and “homosexuality”, and how a penetrator/society-forced womanhood status, this thesis will discuss their effect on how a Muslim man, who takes on a penetrated role in same-sex activities navigate faith and sexual practices, and how religiosity, my existence as a Muslim, and my gender identity and/or expression are not measured by how sinless/sinful I am or by which sin I commit.
ContributorsAlhaoli, Yousef (Author) / Swadener, Elizabeth (Thesis advisor) / Haines, Chad (Committee member) / Lee, Charles (Committee member) / Arizona State University (Publisher)
Created2021