Sistema de transmissão rádio UWB para amplificação digital de áudio com modulação sigma-delta

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresEm resposta às novas necessidades do mercado da electrónica de consumo, as evoluções das tecnologias sem fios são contínuas. Novas técnicas de transmissão rádio têm sido estudadas de modo a permitir o desenvolvimento de sistemas com taxas de transmissão crescentes e em simultâneo permitir o aumento da sua autonomia. Uma destas técnicas promissoras consiste na utilização de sinais Ultra WideBand (UWB). Estes sinais ocupam bandas de frequência bastante superiores aos sistemas já existentes embora com limitações na potência de transmissão devido às restrições regulamentares. Não havendo ainda um modelo ou tecnologia totalmente aceite por todos os grupos de estudo, a maioria das arquitecturas UWB já existentes são de grande complexidade. Um dos primeiros objectivos desta tese é demonstrar que a utilização de sinais UWB não implica necessariamente ritmos de transmissão elevados nem arquitecturas demasiado complexas. É possível implementar uma arquitectura UWB simplificada, que baseada na transmissão de impulsos pode atingir taxas de transmissão moderadas. Uma proposta de utilização deste conceito é outro objectivo da tese. Aliar à transmissão UWB a amplificação de um sinal áudio, com recurso a um amplificador eficiente em potência com modulação digital sigma-delta. No final espera-se obter um sistema de transmissão sem fios para áudio com uma amplificação eficiente e consumo reduzido

大出力システム実現のためのパワー半導体デバイスおよび回路技術に関する研究

The thesis summarizes the power semiconductor device and circuit technologies to realize high power systems. For realizing high power systems, both device technology for high breakdown voltage and circuit design technology to utilize the devices are needed. In power semiconductor devices, because the maximum electric field varies depending on material and device structure, it is indispensable to analyze electric field strength distribution to achieve high breakdown voltage. Then, it is usual that semiconductor devices are designed by applying appropriate electric field relaxation methods, but existing electric field relaxation methods are not sufficient to realize higher breakdown voltage. In the thesis, methodologies to relax maximum electric field for high-k will be described, while applying existing electric field relaxation methods. In the circuit design technology, output voltage range can be extended by changing a source voltage up and down. To vary source voltages, it is necessary to add large size components, which causes increased area for the whole system. In the thesis, a novel circuit configuration which can generate outputs that is higher than source voltage range without changing source voltages. Another techniques needed for digital speaker systems to apply to high output systems will be also presented.博士(工学)法政大学 (Hosei University

High Bandwidth Phase Voltage and Current Control Loop of a Permanent Magnet Synchronous Motor based on Delta Sigma Bitstreams

Delta-Sigma-Umsetzer sind aus der Audio-Technik für ihren hohen Signal-zu-Rausch Abstand bei Abtastraten im 10 bis 100 kHz Bereich bekannt und werden zunehmend auch in der Stromregelung von elektrischen Antrieben als Analog-Digital-Umsetzer eingesetzt. Delta-Sigma-Umsetzer bestehen aus einem Modulator und einem digitalen Tiefpassfilter. Die Auswirkungen des digitalen Filters auf die Stromregelung eines elektrischen Antriebs werden hinsichtlich der erreichbaren Bandbreite des Stromregelkreises und der Unterdrückung von Störungen in der Strommessung untersucht. In dieser Arbeit werden zwei Ansätze zur Steigerung der Bandbreite des Stromregelkreises verfolgt. Der Stromregler wird direkt in dem hochfrequenten Zeitraster (10 MHz) der Delta-Sigma-Modulatoren gerechnet, so dass auf einen digitalen Tiefpassfilter verzichtet werden kann. Dieses Vorgehen erfordert eine neuartige Signalverarbeitung, da der Ausgang des Delta-Sigma-Modulators aus einem gering quantisierten Delta-Sigma-Bitstrom mit einer Auflösung von einem Bit besteht. Die vorhandenen Ansätze zur direkten Signalverarbeitung des Delta-Sigma-Bitstroms werden verglichen und erweitert. Der zweite Ansatz zur Steigerung der Bandbreite besteht darin, die hochfrequenten Delta-Sigma-Bitströme breitbandig in PWM Signale für eine Leistungselektronik im 4 - 40 kHz Bereich umzusetzen. Das grundsätzliche Prinzip wird an einer einphasigen Last untersucht. Die im Stand der Forschung bekannte Lösung für eine dreiphasige Last weist erhebliche Nachteile auf. In dieser Arbeit wird ein Verfahren für einen hochdynamischen dreiphasigen Leistungselektronik-Modulator zur direkten Verarbeitung von Delta-Sigma-Bitströmen vorgestellt, welcher die Nachteile der bekannten Lösung aufhebt. Zusätzlich wird eine direkte Rückführung der Strom- und Spannungsmesswerte über Delta-Sigma-Bitströme realisiert. Dies ermöglicht eine hochdynamische Strom- und Spannungsregelung einer permanenterregten Synchronmaschine.Delta sigma converters are established in communication and audio high fidelity applications due to their high signal to noise ratio and sampling frequency range of 10 to 100 kHz. In the phase current control of electrical drives, delta sigma converters are more commonly used. They comprise a modulator and a digital low pass filter. The effects of the digital low pass filter on the achievable bandwidth and the suppression of disturbances of the electrical drive are analyzed in this thesis. Two measures are proposed to increase the bandwidth of the phase current control loop. The phase current controller is executed at the high frequent (10 MHz) sampling rate of the delta sigma modulator so that the digital filter can be omitted. This method requires a new signal processing, since the output of the delta sigma modulator, a delta sigma bitstream, features only a one bit resolution. Existing solutions for this direct processing of delta sigma bitstreams are compared and extended. A highly dynamic conversion of the high frequent delta sigma bitstream into pulse width modulated signals for power electronics is the second method to increase the bandwidth. The high frequent sampling rate of the delta sigma modulator is reduced to an average switching frequency range of 4 to 40 kHz. A single-phase load is used for a first analysis. The solution for a three-phase load in literature reveals some disadvantages. A power electronics modulator with high bandwidth, which directly processes the delta sigma bitstreams without these disadvantages, is presented. In addition, a direct feedback of phase currents and voltages is achieved by delta sigma bitstreams. This enables a highly dynamic phase current- and voltage control of a permanent magnet synchronous machine