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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Uppochnervända roller hemma hos Martina : En undersökning av den självförringande humorns subversiva kraft i Martina Haags Hemma hos Martina

Bonnard, Erika January 2006 (has links)
Martina Haag’s method of self-mockery used in her chronicles is characterized by her wish to live up to various ideals. This essay brings out the subversive power of self-deprecatory hu-mor expressed in her book Hemma hos Martina. The author’s strategies and kinds of humor are being studied, leading up to what this humor accomplishes. General theories on humor, by Mary Ann Rishel, Maria Ohlsson, Henri Bergson, Joannne R. Gilbert and Simon Critchley are being applied to find the essence of her craftsmanship in writing comedy. The analysis also goes more closely into the style and language, to give a deeper understanding of how she creates jokes, and also how she relates to her ideals through language. The main thrust of the analysis, though, builds on theories on self-deprecatory humor. Haag is included into Joanne R. Gilbert’s theory on self-deprecation and The Whiner within the field of stand-up comedy. Some American feminist critics have rejected self-deprecatory humor as being anti-feminist, stating that women applying this particular kind of humor merely reinforce stereoty-pes, and put themselves down. This paper objects to those critics, leaning on Haag’s book. I wish to show that Haag is not demeaning towards herself, but towards the cultural norms and expectations in our present society. In this context, I show how Haag manages to demystify and criticize ideal representations of women, by lampooning them and revolting against them. In this way, her book turns into a satirical critique of cultural values. My essay illustrates how Haag objectifies herself, making regular use of stereotypes. This is necessary, since these two elements are essential to most humor. Haag confirms stereotypes to make people laugh. This laughter brings about awareness in the reader, making Haag’s work a social critique of current values and norms concerning women.
152

Facies Architecture and Stratigraphy of Tidal Ridges in the Eocene Roda Formation, Northern Spain

Michaud, Kain 02 May 2011 (has links)
ABSTRACT The Eocene Roda Formation in northern Spain documents the deposits from a range of coastal depositional environments. These include alluvial plains, distributary channels, mouth bars, upper to lower-shorefaces, and tidal shelf ridges. Eighteen progradational sand tongues that are interpreted as parasequences compose two third-order sequences. Sequence 1 accumulated in an environment with strong tidal currents and high rates of progradation, while Sequence 2 was deposited under relatively weaker currents and higher rates of aggradation, which produced a higher mudstone:sandstone ratio. The stratigraphy highlights the transgressive origin of six tidal shelf ridges, three in each sequence, that overlie regressive deltaic tongues. Sequence 1 shelf ridges are composed almost entirely of cross-bedded sandstones, whereas Sequence 2 ridges are composed of a mixture of cross-bedded and ripple-laminated deposits. Ridges in both sequences contain bioturbation that is typical of the Cruziana Ichnofacies, and that indicates a marine origin. The tidal ridges are stratigraphically located at or near the point of maximum third-order regression, and are not found within early highstand or late transgressive deposits― times of high relative sea level when the deltaic shoreline did not protrude significantly. Tidal currents were accentuated at the coast when the delta complex had prograded several kilometres into the basin, while during times of high relative sea level, the basin was wider and tidal currents were weaker, consequently leading to a lack of tidal deposits. The tidal ridges are, thus, interpreted as being headland-associated deposits. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2011-04-29 17:10:10.008
153

The Angel in the House och dess motsats i Virginia Woolfs författarskap : En jämförande och analytisk närläsning av kvinnliga karaktärer i The Voyage Out och To the Lighthouse / The Angel in the House and its contrast in the work of Virginia Woolf : A close reading of female characters in The Voyage Out and To the Lighthouse

Bergqvist, Sandra January 2014 (has links)
No description available.
154

Transmitting Quantum Information Reliably across Various Quantum Channels

Ouyang, Yingkai January 2013 (has links)
Transmitting quantum information across quantum channels is an important task. However quantum information is delicate, and is easily corrupted. We address the task of protecting quantum information from an information theoretic perspective -- we encode some message qudits into a quantum code, send the encoded quantum information across the noisy quantum channel, then recover the message qudits by decoding. In this dissertation, we discuss the coding problem from several perspectives.} The noisy quantum channel is one of the central aspects of the quantum coding problem, and hence quantifying the noisy quantum channel from the physical model is an important problem. We work with an explicit physical model -- a pair of initially decoupled quantum harmonic oscillators interacting with a spring-like coupling, where the bath oscillator is initially in a thermal-like state. In particular, we treat the completely positive and trace preserving map on the system as a quantum channel, and study the truncation of the channel by truncating its Kraus set. We thereby derive the matrix elements of the Choi-Jamiolkowski operator of the corresponding truncated channel, which are truncated transition amplitudes. Finally, we give a computable approximation for these truncated transition amplitudes with explicit error bounds, and perform a case study of the oscillators in the off-resonant and weakly-coupled regime numerically. In the context of truncated noisy channels, we revisit the notion of approximate error correction of finite dimension codes. We derive a computationally simple lower bound on the worst case entanglement fidelity of a quantum code, when the truncated recovery map of Leung et. al. is rescaled. As an application, we apply our bound to construct a family of multi-error correcting amplitude damping codes that are permutation-invariant. This demonstrates an explicit example where the specific structure of the noisy channel allows code design out of the stabilizer formalism via purely algebraic means. We study lower bounds on the quantum capacity of adversarial channels, where we restrict the selection of quantum codes to the set of concatenated quantum codes. The adversarial channel is a quantum channel where an adversary corrupts a fixed fraction of qudits sent across a quantum channel in the most malicious way possible. The best known rates of communicating over adversarial channels are given by the quantum Gilbert-Varshamov (GV) bound, that is known to be attainable with random quantum codes. We generalize the classical result of Thommesen to the quantum case, thereby demonstrating the existence of concatenated quantum codes that can asymptotically attain the quantum GV bound. The outer codes are quantum generalized Reed-Solomon codes, and the inner codes are random independently chosen stabilizer codes, where the rates of the inner and outer codes lie in a specified feasible region. We next study upper bounds on the quantum capacity of some low dimension quantum channels. The quantum capacity of a quantum channel is the maximum rate at which quantum information can be transmitted reliably across it, given arbitrarily many uses of it. While it is known that random quantum codes can be used to attain the quantum capacity, the quantum capacity of many classes of channels is undetermined, even for channels of low input and output dimension. For example, depolarizing channels are important quantum channels, but do not have tight numerical bounds. We obtain upper bounds on the quantum capacity of some unital and non-unital channels -- two-qubit Pauli channels, two-qubit depolarizing channels, two-qubit locally symmetric channels, shifted qubit depolarizing channels, and shifted two-qubit Pauli channels -- using the coherent information of some degradable channels. We use the notion of twirling quantum channels, and Smith and Smolin's method of constructing degradable extensions of quantum channels extensively. The degradable channels we introduce, study and use are two-qubit amplitude damping channels. Exploiting the notion of covariant quantum channels, we give sufficient conditions for the quantum capacity of a degradable channel to be the optimal value of a concave program with linear constraints, and show that our two-qubit degradable amplitude damping channels have this property.
155

Revival types : a look at the leaders of the Great Awakening through the lens of psychological type and temperament

Garcia, Yvette D. January 2007 (has links)
Thesis (D. Min.)--Gordon-Conwell Theological Seminary, 2007. / Includes bibliographical references.
156

The myth of the vampire and blood imagery in Bram Stoker's Dracula

Zanini, Claudio Vescia January 2007 (has links)
O objetivo deste trabalho é apresentar uma leitura do romance Drácula, do escritor irlandês Bram Stoker, publicado em 1897. O propósito do estudo é identificar os arquétipos e imagens predominantes em Drácula, mostrando em que medida eles representam questões pertinentes à sociedade vitoriana e aos públicos receptores que obra teve desde então. A obra é publicada em um momento histórico que se configura ponto crucial na conflituada transição entre os antigos valores rurais britânicos e os da moderna sociedade urbana contemporânea, e a conseqüência desta transição é uma mudança drástica no código comportamental britânico. Diversos elementos desta transformação podem ser identificados nas representações simbólicas encontradas no romance de Stoker, e a voracidade com que a obra é consumida pelos leitores desde a época vitoriana se configura sintoma das premências decorrentes da excessiva repressão daquele período. A análise do arquétipo do vampiro e das imagens arquetípicas apresentadas em Drácula se dará predominantemente através do exame das implicações psicológicas e antropológicas ligadas ao imaginário do Sangue. O embasamento teórico se ampara nas contribuições prestadas por Carl Gustav Jung e Gilbert Durand. A dissertação vem subdividida em três capítulos. Na primeira parte do capítulo um apresento as contextualizações referentes a certos fenômenos observados na sociedade vitoriana, especialmente no que tange às implicaturas de gênero no código comportamental da época, e na segunda apresento contextualizações referentes a personagens históricos que influenciaram Bram Stoker na criação de seu personagem principal. No segundo capítulo, remeto ao embasamento teórico, apresentando os conceitos definidos por Jung nos quais a leitura do capítulo 3 se ampara, bem como analiso símbolos, imagens e arquétipos em Drácula de acordo com os regimes da imaginação propostos por Durand. No terceiro capítulo ofereço minha leitura do romance, na qual identifico e analiso imagens e símbolos do Sangue presentes no romance. Na conclusão, apresento as últimas considerações, com o intuito de ratificar as fortes ligações que se estabelecem entre os significados velados inscritos no romance e as vivências da sociedade receptora, tendo como base o mito do vampiro e sua associação com o imaginário do sangue na tentativa de explicar a bemsucedida e contínua recepção do romance. / The aim of this thesis is to present a reading of Dracula, published in 1897 by the Irish author Bram Stoker. The purpose of the investigation is to identify the predominant archetypes and images in Dracula, showing to what extent they represent relevant issues to Victorian society and the audiences the novel has had since then. The work is published in a crucial historical moment, during which the British traditional rural values are replaced by modern and urban ones. A major consequence of such a transition is a drastic change in the British behavioral code. Several elements in such a transformation can be identified in Stoker’s novel, and the eagerness with which the work was accepted by Victorian audiences is a symptom of the needs that resulted from the excessive repression from that period. The analysis of the archetype of the vampire and the archetypal images presented in Dracula unfolds predominantly through the examination of the psychological and anthropological implications connected to blood imagery. The main theoretical tools come from the studies of Carl Gustav Jung and Gilbert Durand. The thesis is subdivided in three chapters. In the first part of chapter one I present some contextualization referring to certain phenomena perceived in the Victorian society, mainly the ones regarding the gender implications in the behavioral code of the time, and in the second part I present contextualization connected to historical characters who influenced Bram Stoker in the creation of his main character. In chapter two I present the theoretical approach, introducing the concepts defined by Jung upon which the reading in chapter 3 is based. I also analyze symbols, images and archetypes in Dracula according to the orders of the image proposed by Durand. In chapter three I offer my reading, identifying and analyzing blood images and symbols in the novel. In the conclusion, I present the final considerations, with the purpose of ratifying the strong bonds connecting the underlying meanings present in the novel and the life experience of the audience, having as a basis the myth of the vampire and its association to the blood imaginary, in an attempt to explain the successful and continuous reception of the novel.
157

Design of CMOS active downconversion mixers for gigahertz multi-band and multiple-standard operation / Um misturador ativo CMOS para conversão a baixas frequências com operacão multi-banda e multi-protocolo

Cordova Vivas, David Javier January 2014 (has links)
Os requisitos de linearidade e ruído em aplicações multi-banda e multi-protocolo fazem que o projeto de misturadores RF seja uma tarefa muito desafiadora. Nesta dissertação dois misturadores com base na topologia célula de Gilbert são propostas. Linearidade e ruído foram as principais figuras de mérito consideradas para o misturadores propostos. Para aumento linearidade, foi utilizada uma técnica de cancelamento de harmônicas pós-distorção (PDHC). E, para redução de ruído, foi utilizado um circuito de redução dinâmica de corrente combinada com um filtro LC sintonizado na frequência do LO e cancelamento de ruído térmico. A análise por séries Volterra do estágio transcondutância do misturador proposto é reportada para mostrar a eficácia da técnica de cancelamento de harmônicos com pósdistorção. O circuito de linearização adicionado não aumenta o tamanho do misturador, nem degrada ganho de conversão, figura de ruído, ou consumo de potência. Simulações elétricas foram realizadas em nível de pós-layout para a primeira topologia e nível esquemático para a segunda topologia, usando processo CMOS de 0.13 mm da IBM. As melhorias em IIP2 e IIP3 são apresentadas em comparação com o misturador do tipo célula de Gilbert convencional. Para a primeira topologia, foi obtido um ganho de conversão de 10.2 dB com uma NF de 12 dB para o misturador projetado funcionando a 2 GHz, com uma frequência intermediária de 500 kHz. E um IIP2 e IIP3 de 55 dBm e 10.9 dBm, respectivamente, consumindo apenas 5.3 mW de uma fonte de 1.2 V. Para a segunda topologia, foram obtidos um ganho de conversão de [13.8 ~11] dB, um coeficiente de reflexão na entrada (S11) de [-18 ~-9.5] dB e um NF de [8.5 ~11] dB no intervalo de 1 a 6 GHz. Para as especificações de linearidade, um valor médio de IIP3 de 0 dBm foi alcançado para toda a faixa de frequência, consumindo 19.3 mW a partir de uma fonte de 1.2 V. Especificações adequadas para operação multi-banda e multi-protocolo. / The linearity and noise requirements in multi-band multi-standard applications make the design of RF CMOS mixers a very challenging task. In this dissertation two downconversion mixers based on the Gilbert-cell topology are proposed. Linearity and noise were the principal figures of merit for the proposed mixers. For linearity improvement, post distortion harmonic cancellation (PDHC) was employed. And, for noise reduction, dynamic current injection combined with an LC filter tuned at the LO frequency and thermal-noise cancellation were used. A Volterra series analysis of the transconductance stage is reported to show the effectiveness of the post-distortion harmonic cancellation technique. The added linearization circuitry does not increase the size of the mixer, nor does it degrade conversion gain, noise figure, or power consumption. Electrical simulations were performed on extracted layout level from the first topology and schematic level from the second topology. Using an IBM 0.13 mm CMOS process improvements on IIP3 and IIP2 in comparison to the conventional Gilbert-cell mixer are demonstrated. For the first topology, we achieved a conversion gain of 10.2 dB with a NF of 12 dB for the designed mixer working at 2 GHz, with a low-IF of 500 kHz and an IIP2 and IIP3 of 55 dBm and 10.9 dBm, respectively, while consuming only 5.3 mW from a 1.2 V supply. For the second topology, we achieved a conversion gain range of [13.8 ~11] dB, an input reflection coefficient (S11) of [-18 ~-9.5] dB and a NF of [8.5 ~11] dB in the frequency range of 1 to 6 GHz. For the linearity specs, an IIP3 of 0 dBm was achieved for the whole frequency range, while consuming 19.3 mW from a 1.2 V supply, making the second topology well suited for multi-band and multi-standard operation.
158

Culpado ou inocente : o supense de Poe, Chesterton e Hitchcock

Silva, Daniel Lukan Schimith 01 December 2017 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Letras, Departamento de Teoria Literária e Literaturas, Programa de Pós-Graduação em Literatura, 2017. / Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2018-04-09T18:44:02Z No. of bitstreams: 1 2017_DanielLukanSchimithSilva.pdf: 1788519 bytes, checksum: 8f4472fbd46866d98610ec9a2fd1f3fc (MD5) / Approved for entry into archive by Raquel Viana (raquelviana@bce.unb.br) on 2018-04-17T21:21:39Z (GMT) No. of bitstreams: 1 2017_DanielLukanSchimithSilva.pdf: 1788519 bytes, checksum: 8f4472fbd46866d98610ec9a2fd1f3fc (MD5) / Made available in DSpace on 2018-04-17T21:21:39Z (GMT). No. of bitstreams: 1 2017_DanielLukanSchimithSilva.pdf: 1788519 bytes, checksum: 8f4472fbd46866d98610ec9a2fd1f3fc (MD5) Previous issue date: 2018-04-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). / Essa pesquisa tem como objetivo principal investigar a composição do suspense narrativo – suas origens e implicações – a partir da análise das obras de Edgar Allan Poe, G.K. Chesterton e Alfred Hitchcock. Tendo como base o levantamento feito na obra de dois grandes nomes da crime-fiction literária e uma análise na obra cinematográfica do ‘mestre do suspense’, definiu-se os contos The Black Cat, de Poe, e The Honour of Israel Gow, de Chesterton, além do filme The Lodger, de Hitchcock, como modelos de narrativas paradigmáticas no conjunto das obras de cada um dos artistas em questão. Desse modo, com base nas análises narrativas e no aporte teórico acerca do suspense, colocar-se-á o embate entre culpa e inocência como elemento comum às narrativas dos três autores; bem como será discutida a hipótese de que, a partir da convergência entre elementos peculiares à obra de Poe e os particulares à obra de Chesterton, Hitchcock conseguiu criar um suspense moral bastante característico ao seu estilo de crime-fiction cinematográfico. Ou seja, como base numa simples ligação inicial – a crime-fiction – essa pesquisa pretende levantar o máximo de informações e conexões nos contos e no filme em análise a fim de compreender o suspense e o medo originados no conflito entre culpa e inocência, tanto na literatura quanto no cinema. / This research has as main objective investigating the composition of suspense narratives – their origins and implications – from the analysis of the works of Edgar Allan Poe, G.K. Chesterton and Alfred Hitchcock. On the basis of the survey on the works of two great names in literary crime-fiction and the examination on the filmography of ‘the master of suspense’: Poe’s Black Cat, Chesterton’s The Honor of Israel Gow and Hitchcock's The Lodger are defined as models of paradigmatic narratives in the oeuvres of each artist in question. Thus, based on the narrative analysis and the theoretical support about suspense, the contrast between blame and innocence will be assigned as a common element to the narratives of the three authors; as well as it will be discussed the hypothesis that Hitchcock created a moral suspense, quite characteristic to his cinema style of crime-fiction, from the convergence between peculiar elements of Poe’s work and odd elements of Chesterton’s work. In other words, based on a simple initial connection – the crime-fiction – this research intends to collect the maximum information on the stories under analysis in order to comprehend the suspense and the fear originated in the conflict between guilt and innocence, in both arts (cinema and literature).
159

The myth of the vampire and blood imagery in Bram Stoker's Dracula

Zanini, Claudio Vescia January 2007 (has links)
O objetivo deste trabalho é apresentar uma leitura do romance Drácula, do escritor irlandês Bram Stoker, publicado em 1897. O propósito do estudo é identificar os arquétipos e imagens predominantes em Drácula, mostrando em que medida eles representam questões pertinentes à sociedade vitoriana e aos públicos receptores que obra teve desde então. A obra é publicada em um momento histórico que se configura ponto crucial na conflituada transição entre os antigos valores rurais britânicos e os da moderna sociedade urbana contemporânea, e a conseqüência desta transição é uma mudança drástica no código comportamental britânico. Diversos elementos desta transformação podem ser identificados nas representações simbólicas encontradas no romance de Stoker, e a voracidade com que a obra é consumida pelos leitores desde a época vitoriana se configura sintoma das premências decorrentes da excessiva repressão daquele período. A análise do arquétipo do vampiro e das imagens arquetípicas apresentadas em Drácula se dará predominantemente através do exame das implicações psicológicas e antropológicas ligadas ao imaginário do Sangue. O embasamento teórico se ampara nas contribuições prestadas por Carl Gustav Jung e Gilbert Durand. A dissertação vem subdividida em três capítulos. Na primeira parte do capítulo um apresento as contextualizações referentes a certos fenômenos observados na sociedade vitoriana, especialmente no que tange às implicaturas de gênero no código comportamental da época, e na segunda apresento contextualizações referentes a personagens históricos que influenciaram Bram Stoker na criação de seu personagem principal. No segundo capítulo, remeto ao embasamento teórico, apresentando os conceitos definidos por Jung nos quais a leitura do capítulo 3 se ampara, bem como analiso símbolos, imagens e arquétipos em Drácula de acordo com os regimes da imaginação propostos por Durand. No terceiro capítulo ofereço minha leitura do romance, na qual identifico e analiso imagens e símbolos do Sangue presentes no romance. Na conclusão, apresento as últimas considerações, com o intuito de ratificar as fortes ligações que se estabelecem entre os significados velados inscritos no romance e as vivências da sociedade receptora, tendo como base o mito do vampiro e sua associação com o imaginário do sangue na tentativa de explicar a bemsucedida e contínua recepção do romance. / The aim of this thesis is to present a reading of Dracula, published in 1897 by the Irish author Bram Stoker. The purpose of the investigation is to identify the predominant archetypes and images in Dracula, showing to what extent they represent relevant issues to Victorian society and the audiences the novel has had since then. The work is published in a crucial historical moment, during which the British traditional rural values are replaced by modern and urban ones. A major consequence of such a transition is a drastic change in the British behavioral code. Several elements in such a transformation can be identified in Stoker’s novel, and the eagerness with which the work was accepted by Victorian audiences is a symptom of the needs that resulted from the excessive repression from that period. The analysis of the archetype of the vampire and the archetypal images presented in Dracula unfolds predominantly through the examination of the psychological and anthropological implications connected to blood imagery. The main theoretical tools come from the studies of Carl Gustav Jung and Gilbert Durand. The thesis is subdivided in three chapters. In the first part of chapter one I present some contextualization referring to certain phenomena perceived in the Victorian society, mainly the ones regarding the gender implications in the behavioral code of the time, and in the second part I present contextualization connected to historical characters who influenced Bram Stoker in the creation of his main character. In chapter two I present the theoretical approach, introducing the concepts defined by Jung upon which the reading in chapter 3 is based. I also analyze symbols, images and archetypes in Dracula according to the orders of the image proposed by Durand. In chapter three I offer my reading, identifying and analyzing blood images and symbols in the novel. In the conclusion, I present the final considerations, with the purpose of ratifying the strong bonds connecting the underlying meanings present in the novel and the life experience of the audience, having as a basis the myth of the vampire and its association to the blood imaginary, in an attempt to explain the successful and continuous reception of the novel.
160

Design of CMOS active downconversion mixers for gigahertz multi-band and multiple-standard operation / Um misturador ativo CMOS para conversão a baixas frequências com operacão multi-banda e multi-protocolo

Cordova Vivas, David Javier January 2014 (has links)
Os requisitos de linearidade e ruído em aplicações multi-banda e multi-protocolo fazem que o projeto de misturadores RF seja uma tarefa muito desafiadora. Nesta dissertação dois misturadores com base na topologia célula de Gilbert são propostas. Linearidade e ruído foram as principais figuras de mérito consideradas para o misturadores propostos. Para aumento linearidade, foi utilizada uma técnica de cancelamento de harmônicas pós-distorção (PDHC). E, para redução de ruído, foi utilizado um circuito de redução dinâmica de corrente combinada com um filtro LC sintonizado na frequência do LO e cancelamento de ruído térmico. A análise por séries Volterra do estágio transcondutância do misturador proposto é reportada para mostrar a eficácia da técnica de cancelamento de harmônicos com pósdistorção. O circuito de linearização adicionado não aumenta o tamanho do misturador, nem degrada ganho de conversão, figura de ruído, ou consumo de potência. Simulações elétricas foram realizadas em nível de pós-layout para a primeira topologia e nível esquemático para a segunda topologia, usando processo CMOS de 0.13 mm da IBM. As melhorias em IIP2 e IIP3 são apresentadas em comparação com o misturador do tipo célula de Gilbert convencional. Para a primeira topologia, foi obtido um ganho de conversão de 10.2 dB com uma NF de 12 dB para o misturador projetado funcionando a 2 GHz, com uma frequência intermediária de 500 kHz. E um IIP2 e IIP3 de 55 dBm e 10.9 dBm, respectivamente, consumindo apenas 5.3 mW de uma fonte de 1.2 V. Para a segunda topologia, foram obtidos um ganho de conversão de [13.8 ~11] dB, um coeficiente de reflexão na entrada (S11) de [-18 ~-9.5] dB e um NF de [8.5 ~11] dB no intervalo de 1 a 6 GHz. Para as especificações de linearidade, um valor médio de IIP3 de 0 dBm foi alcançado para toda a faixa de frequência, consumindo 19.3 mW a partir de uma fonte de 1.2 V. Especificações adequadas para operação multi-banda e multi-protocolo. / The linearity and noise requirements in multi-band multi-standard applications make the design of RF CMOS mixers a very challenging task. In this dissertation two downconversion mixers based on the Gilbert-cell topology are proposed. Linearity and noise were the principal figures of merit for the proposed mixers. For linearity improvement, post distortion harmonic cancellation (PDHC) was employed. And, for noise reduction, dynamic current injection combined with an LC filter tuned at the LO frequency and thermal-noise cancellation were used. A Volterra series analysis of the transconductance stage is reported to show the effectiveness of the post-distortion harmonic cancellation technique. The added linearization circuitry does not increase the size of the mixer, nor does it degrade conversion gain, noise figure, or power consumption. Electrical simulations were performed on extracted layout level from the first topology and schematic level from the second topology. Using an IBM 0.13 mm CMOS process improvements on IIP3 and IIP2 in comparison to the conventional Gilbert-cell mixer are demonstrated. For the first topology, we achieved a conversion gain of 10.2 dB with a NF of 12 dB for the designed mixer working at 2 GHz, with a low-IF of 500 kHz and an IIP2 and IIP3 of 55 dBm and 10.9 dBm, respectively, while consuming only 5.3 mW from a 1.2 V supply. For the second topology, we achieved a conversion gain range of [13.8 ~11] dB, an input reflection coefficient (S11) of [-18 ~-9.5] dB and a NF of [8.5 ~11] dB in the frequency range of 1 to 6 GHz. For the linearity specs, an IIP3 of 0 dBm was achieved for the whole frequency range, while consuming 19.3 mW from a 1.2 V supply, making the second topology well suited for multi-band and multi-standard operation.

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