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- All Subjects: engineering
- Creators: Bakkaloglu, Bertan
Description
Pulse Density Modulation- (PDM-) based class-D amplifiers can reduce non-linearity and tonal content due to carrier signal in Pulse Width Modulation - (PWM-) based amplifiers. However, their low-voltage analog implementations also require a linear- loop filter and a quantizer. A PDM-based class-D audio amplifier using a frequency-domain quantization is presented in this paper. The digital-intensive frequency domain approach achieves high linearity under low-supply regimes. An analog comparator and a single-bit quantizer are replaced with a Current-Controlled Oscillator- (ICO-) based frequency discriminator. By using the ICO as a phase integrator, a third-order noise shaping is achieved using only two analog integrators. A single-loop, singlebit class-D audio amplifier is presented with an H-bridge switching power stage, which is designed and fabricated on a 0.18 um CMOS process, with 6 layers of metal achieving a total harmonic distortion plus noise (THD+N) of 0.065% and a peak power efficiency of 80% while driving a 4-ohms loudspeaker load. The amplifier can deliver the output power of 280 mW.
ContributorsLee, Junghan (Author) / Bakkaloglu, Bertan (Thesis advisor) / Kiaei, Sayfe (Committee member) / Ozev, Sule (Committee member) / Song, Hongjiang (Committee member) / Arizona State University (Publisher)
Created2011
Description
ABSTRACT To meet stringent market demands, manufacturers must produce Radio Frequency (RF) transceivers that provide wireless communication between electronic components used in consumer products at extremely low cost. Semiconductor manufacturers are in a steady race to increase integration levels through advanced system-on-chip (SoC) technology. The testing costs of these devices tend to increase with higher integration levels. As the integration levels increase and the devices get faster, the need for high-calibre low cost test equipment become highly dominant. However testing the overall system becomes harder and more expensive. Traditionally, the transceiver system is tested in two steps utilizing high-calibre RF instrumentation and mixed-signal testers, with separate measurement setups for transmitter and receiver paths. Impairments in the RF front-end, such as the I/Q gain and phase imbalance and nonlinearity, severely affect the performance of the device. The transceiver needs to be characterized in terms of these impairments in order to guarantee good performance and specification requirements. The motivation factor for this thesis is to come up with a low cost and computationally simple extraction technique of these impairments. In the proposed extraction technique, the mapping between transmitter input signals and receiver output signals are used to extract the impairment and nonlinearity parameters. This is done with the help of detailed mathematical modeling of the transceiver. While the overall behavior is nonlinear, both linear and nonlinear models to be used under different test setups are developed. A two step extraction technique has been proposed in this work. The extraction of system parameters is performed by using the mathematical model developed along with a genetic algorithm implemented in MATLAB. The technique yields good extraction results with reasonable error. It uses simple mathematical operation which makes the extraction fast and computationally simple when compared to other existing techniques such as traditional two step dedicated approach, Nonlinear Solver (NLS) approach, etc. It employs frequency domain analysis of low frequency input and output signals, over cumbersome time domain computations. Thus a test method, including detailed behavioral modeling of the transceiver, appropriate test signal design along with a simple algorithm for extraction is presented.
ContributorsSreenivassan, Aiswariya (Author) / Ozev, Sule (Thesis advisor) / Kiaei, Sayfe (Committee member) / Bakkaloglu, Bertan (Committee member) / Arizona State University (Publisher)
Created2011
Description
The partially-depleted (PD) silicon Metal Semiconductor Field Effect Transistor (MESFET) is becoming more and more attractive for analog and RF applications due to its high breakdown voltage. Compared to conventional CMOS high voltage transistors, the silicon MESFET can be fabricated in commercial standard Silicon-on-Insulator (SOI) CMOS foundries without any change to the process. The transition frequency of the device is demonstrated to be 45GHz, which makes the MESFET suitable for applications in high power RF power amplifier designs. Also, high breakdown voltage and low turn-on resistance make it the ideal choice for switches in the switching regulator designs. One of the anticipated applications of the MESFET is for the pass device for a low dropout linear regulator. Conventional NMOS and PMOS linear regulators suffer from high dropout voltage, low bandwidth and poor stability issues. In contrast, the N-MESFET pass transistor can provide an ultra-low dropout voltage and high bandwidth without the need for an external compensation capacitor to ensure stability. In this thesis, the design theory and problems of the conventional linear regulators are discussed. N-MESFET low dropout regulators are evaluated and characterized. The error amplifier used a folded cascode architecture with gain boosting. The source follower topology is utilized as the buffer to sink the gate leakage current from the MESFET. A shunt-feedback transistor is added to reduce the output impedance and provide the current adaptively. Measurement results show that the dropout voltage is less than 150 mV for a 1A load current at 1.8V output. Radiation measurements were done for discrete MESFET and fully integrated LDO regulators, which demonstrate their radiation tolerance ability for aerospace applications.
ContributorsChen, Bo (Author) / Thornton, Trevor (Thesis advisor) / Bakkaloglu, Bertan (Committee member) / Goryll, Michael (Committee member) / Arizona State University (Publisher)
Created2013
Description
This focuses on recent changes in Arizona eminent domain law regarding the question of whether a use be "truly public." In light of the landmark decision in Bailey v City of Mesa--often lauded as a great victory for proponents of private property rights-- a few sources will be reviewed to provide an indication of the extent redevelopment in Arizona has been affected by the decision. While the result in Bailey, precluding the City from taking the subject property may have been the correct outcome, the test to which the case now subjects any similar case involving redevelopment has made it unnecessarily difficult for political subdivisions of the state to carry out legislated redevelopment goals. The Bailey case only served to convolute the question of "public use" in the context of economic development, rather than create a workable body of law. In addition to providing a historical context and analyzing the effect of new interpretations on redevelopment generally, this paper will critique the Bailey decision in order to resolve the conflict that the decision created: that of the redevelopment goals of the state and municipalities and the authorized use of condemnation to achieve these goals with the judiciary's decision to greatly restrict the use of condemnation for the achievement of redevelopment goals. Arguably this conflict arose from a failure to fully understand the complexities of the use of the power of eminent domain for redevelopment purposes. Unaware of the need to use eminent domain in order to speed along and make possible economic redevelopment, overzealous proponents of property rights have reduced the issue to a narrow view of the state vs. the individual. Hopefully this paper can offer a more moderate and unbiased view of the use of eminent domain in light of the charge of the state and municipalities to facilitate economic growth.
ContributorsStern-Sapad, Zalman Badi (Author) / Birnbaum, Gary (Thesis director) / Braselton, James (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor)
Created2015-05
Description
Abstract I sought out a project that would be able to intertwine the topics of business law and the business of sports. After reading and researching a few different options, one combination of law and sports that stood out to me was the frequent labor disputes between NHL owners and the players' union. The main goal of this project was to examine whether or not the lockouts that were instituted by National Hockey League owners during the labor disputes that occurred in 2004 and 2012 actually left the league with a better long term financial and social landscape. Through the examination of the stakeholders that were involved in each dispute and their resulting situations, I presented my answer to the above question. In order to properly study the overall situation, I also discussed the history of sports business, the history of the National Hockey League's business landscape, and collective bargaining in sports amongst other topics.
ContributorsNix, Eric Anthony (Author) / Eaton, John (Thesis director) / Kutz, Elana (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor) / W. P. Carey School of Business (Contributor)
Created2015-05
Description
This thesis will focus on the organizational structures and leadership challenges within private law firms. It begins by explaining the different roles within the organizational structure. It will then discuss various other duties that are carried out by lawyers in addition to legal work. Through the use of qualitative methodology, including a review of scholarly literature and semi-formal interviews with private firm partners, this research mainly focuses on the challenges that exist in private law firms. The study concludes with possible solutions to address the discussed challenges in private law firms.
ContributorsKrikorian, Dikranouhi (Author) / Trujillo, Rhett (Thesis director) / Waldman, David (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Department of Management (Contributor)
Created2015-05
Description
Contributing to the small but growing body of research on linguistic discrimination in legal settings, this thesis conducts a sociolinguistic investigation of the impact of an individual's accent on juror perceptions of defendant favorability and innocence. The study used an online questionnaire in which sixty mock jurors were each asked to evaluate the audio testimony of a defendant representing one of three English ethnolects: African American, British South African, or Caucasian American. In addition to rating the defendant's persuasiveness, honesty, credibility, trustworthiness, and guilt, participants were also asked to determine an appropriate punishment (if any) for the defendant. Results indicate a preference of participants to issue an unsure or caveat opinion for the African American speaker but not to the British South African or Caucasian American speaker. The implications of these findings, as well as the correlations between each variable are discussed. The paper concludes with a recommendation for legal training and a revision of courtroom practices.
ContributorsMaerowitz, Max Robert (Author) / Prior, Matthew (Thesis director) / Adams, Karen (Committee member) / Barrett, The Honors College (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / Department of English (Contributor)
Created2014-05
Description
Certain laws relating to self-defense were created known as "Stand Your Ground" laws. The public has interpreted these laws in ways that expand them beyond their original scope. To gain an understanding of self-defense laws, a look at the origins of self-defense is needed. Following the historical background, several cases will be examined that illustrate how the public has interpreted "Stand Your Ground" laws, and how these interpretations clash with elements of self-defense. Several philosophical principles including natural rights, the social contract, and some form of utilitarianism, will be discussed in relation to "Stand Your Ground" laws. A possible conclusion can be drawn that by misinterpreting "Stand Your Ground" laws, people compromise the philosophical ideals they hold, and infringe on other people's natural rights, break the social contract, and create societal unhappiness. Finally, some people are calling for reform of "Stand Your Ground" laws. These reforms focus on correcting public perception of "Stand Your Ground" laws.
ContributorsSmith, Geramya Joseph (Author) / Sigler, Mary (Thesis director) / Stanford, Michael (Committee member) / Kader, David (Committee member) / Barrett, The Honors College (Contributor) / Sandra Day O'Connor College of Law (Contributor) / W. P. Carey School of Business (Contributor)
Created2013-05
Description
Volume depletion can lead to migraines, dizziness, and significant decreases in a subject's ability to physically perform. A major cause of volume depletion is dehydration, or loss in fluids due to an imbalance in fluid intake to fluid excretion. Because proper levels of hydration are necessary in order to maintain both short and long term health, the ability to monitor hydration levels is growing in clinical demand. Although devices capable of monitoring hydration level exist, these devices are expensive, invasive, or inaccurate and do not offer a continuous mode of measurement. The ideal hydration monitor for consumer use needs to be characterized by its portability, affordability, and accuracy. Also, this device would need to be noninvasive and offer continuous hydration monitoring in order to accurately assess fluctuations in hydration data throughout a specified time period. One particular method for hydration monitoring that fits the majority of these criteria is known as bioelectric impedance analysis (BIA). Although current devices using BIA do not provide acceptable levels of accuracy, portability, or continuity in data collection, BIA could potentially be modified to fit many, if not all, desired customer specifications. The analysis presented here assesses the viability of using BIA as a new standard in hydration level measurement. The analysis uses data collected from 22 subjects using an existing device that employs BIA. A regression derived for estimating TBW based on the parameters of age, weight, height, sex, and impedance is presented. Using impedance data collected for each subject, a regression was also derived for estimating impedance based on the factors of age, weight, height, and sex. The derived regression was then used to calculate a new impedance value for each subject, and these new impedance values were used to estimate TBW. Through a paired-t test between the TBW values derived by using the direct measurements versus the calculated measurements of impedance, the two samples were found to be comparable. Considerations for BIA as a noninvasive measurement of hydration are discussed.
ContributorsTenorio, Jorge Antonio (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
ABSTRACT Ongoing research into wireless transceivers in the 60 GHz band is required to address the demand for high data rate communications systems at a frequency where signal propagation is challenging even over short ranges. This thesis proposes a mixer architecture in Complementary Metal Oxide Semiconductor (CMOS) technology that uses a voltage controlled oscillator (VCO) operating at a fractional multiple of the desired output signal. The proposed topology is different from conventional subharmonic mixing in that the oscillator phase generation circuitry usually required for such a circuit is unnecessary. Analysis and simulations are performed on the proposed mixer circuit in an IBM 90 nm RF process on a 1.2 V supply. A typical RF transmitter system is considered in determining the block requirements needed for the mixer to meet the IEEE 802.11ad 60 GHz Draft Physical Layer Specification. The proposed circuit has a conversion loss of 21 dB at 60 GHz with a 5 dBm LO power at 20 GHz. Input-referred third-order intercept point (IIP3) is 2.93 dBm. The gain and linearity of the proposed mixer are sufficient for Orthogonal Frequency Division Multiplexing (OFDM) modulation at 60 GHz with a transmitted data rate of over 4 Gbps.
ContributorsMartino, Todd Jeffrey (Author) / Kiaei, Sayfe (Thesis advisor) / Bakkaloglu, Bertan (Committee member) / Aberle, James T., 1961- (Committee member) / Arizona State University (Publisher)
Created2010