In modern telecommunications, there is a need for quadrature oscillator exhibiting an accurate and stable phase relation. For example, identical two mutually coupled relaxation oscillator can generate identical quadrature signals, and have extremely accurate and stable phase relation. In this thesis, we propose a current cross-coupled relaxation oscillator with quadrature outputs. The oscillator consists of two identical current relaxation oscillators and a current comparator. The circuit takes the high frequency advantage of current mode circuit. Because of cross-coupled feedback, this oscillator have highly accurate ( <1¢X) and stable quadrature outputs. It is implemented by using TSMC 0.35£gm 2P4M CMOS technology.

A 2.5V 8-bit 100MSample/sec folding and interpolation analog to digital converter is described in this thesis. First, a cascoding folding amplifier is used for improve power consumption. The differential pairs of the folding amplifier are cascoded to reduce the numbers of reference current source, so the power consumption is reduced. In order to reduce more power consumption, we drop the power supply down to 2.5V. However, the power supply is not large enough to keep the folding amplifier working normally and it causes the output signal aberration. Hence, we propose a back-end amplifier to connect the folding amplifier to overcome the problem. Therefore, the power consumption of all circuit is reduced to 15.292mW. Moreover, the capacitive loading at the output of the cascoded differential pairs is smaller than that of conventional cascaded differential pairs, and we employ a distributed folding technique to reduce the folding factors of each folding amplifier. Therefore, we improve the frequency multiplication effect to increase the analog input signal bandwidth. Beside, in order to heave the input signal range of the voltage mode comparator, we employ an n-channel input stage. Because the input signal range of n-channel is higher than that of p-channel input stage. By using these techniques, the input signal bandwidth and the power consumption of overall circuit are improved greatly. The proposed analog to digital converter is designed by TSMC 0.35£gm 2P4M CMOS process, and it operates at 2.5V power supply voltage with 1V to 2.4V reference voltage. The simulation results show that the power consumption is 15.292mW, DNL is +/- 0.55LSB, and INL is 1.7LSB ~ -0.8LSB.

The thesis proposes an integrator with an OPAMP in the feedback loop to fulfill 1MHz bandwidth SI Sigma Delta modulator. The OPAMP is used to pull down the input impedance and get high speed and high resolution. Oversampling and noise shaping are the two keys of Sigma Delta modulator. In structure, multistage is helpful for depressing noises and we use three stages to fulfill this 4-order proposed Sigma Delta modulator. The proposed Sigma Delta modulator uses TSMC 0.18£gm CMOS process and it is a 4-order and three stages SI Sigma Delta modulator. The sampling rate is 32MHz, bandwidth is 1MHz, and oversampling ratio is 16.

[pt] Esta Dissertação de Mestrado apresenta uma metodologia para analisar transformadores para instrumentos (TI) em geral, e vários tipos de transformadores de corrente (TC-s) para medição. O funcionamento e as características dos transformadores de potencial (TP-s) e dos TC-s estão sendo analisados, usando-se as ferramentas tradicionais (circuito equivalente e representação fasorial). O tratamento generalizado facilita a comparação entre TP-s e TC-s e a análise qualitativa dos parâmetros que influenciam os erros de relação e de ângulo de fase.Após verificação geral, quatro tipos de TC-s estão sendo estudados detalhadamente. Para analisar construções eletromagnéticas mais complexas, um método não tradicional está sendo aplicado. Usando-se as representações fasoriais,realiza-se o cálculo baseando-se nas equações elétricas e nas equações magnéticas. O erro complexo do TC é o resultado das soluções destas equações, e vem expresso em função dos parâmetros de construção. Os resultados facilitam comparar o desempenho de vários tipos de TC-s existentes e/ou a serem projetados. Um programa de simulação, utilizando a linguagem C no ambiente LabWindows/CVI - C for Virtual Instrumentation (National Instruments), foi desenvolvido com base nas equações para o cálculo do erro. O programa analisa o comportamento de 4 tipos de TC-s, existentes e/ou a serem projetados, quanto ao erro de relação e ao ângulo de fase. A partir do tipo de material, da dimensão do núcleo e do tipo de enrolamentos, em modo interativo, pode-se escolher várias combinações dos parâmetros em etapas repetidas. A eficiência do método aplicado foi verificada e comprovada. Os resultados são coerentes e quando usados no programa de simulação, resultam em um novo método para analisar, projetar ou escolher um TC para uma finalidade específica. / [en] This dissertation for a master degree presents a methodology to analyse Instrument Transformers in general terms and several types of Current Transformers (CT`s) for measurements, in details.At first, operation and characteristics of Potential Transformers (PT` s) and that of CT` s are analysed, using traditional tools (as equivalent circuits and fasorial representation). The generalised treatment facilitates the comparison between PT` s and CT` s as well as a qualitative analysis of the parameters influencing the ratio and phase errors. After giving a general view, four types of CT` s are studied in details. To analyse complex electromagnetic constructions, a non-traditional method is applied. By using fasorial representations, calculus is based on defining separate groups of electrical and magnetic equations to describe a device. The result of the solution of this set of equations is the complex error of the CT, which is being expressed exclusively in terms of parameters of the construction. The results facilitate the comparison of the performance of various types of CT` s, that exist or are to be designed. A simulation program, using language C, in the ambient of LabWindows/CVI - C for Virtual Instrumentation (National Instruments), was developed, in order to calculate the errors, based upon the equations obtained. The program is capable of specifying the parameters and analysing the characteristics of four types of CT` s, representing finally the ratio and phase errors, in terms of the variation of the current or that of the load. Characteristics of various magnet ic materials, dimensions ofstandardized toroidal cores and that of wires can be specified, stored and selected thereafter. The program facilitates experimenting with various combinations of parameters in an interactive mode and to approximate optimised constructions in iterative steps. Efficiency of the method was verified and proved. The results are coherent and when are used in the simulation program, represent a new method to analyse an existing CT or to design a new one, or to select the most adequate model for a specific purpose.

Dans un contexte de besoin grandissant en précision dans la mesure des faibles courants pour les instituts nationaux de métrologie, l’industrie, les fabricants d’instruments et la physique fondamentale, l’étude des dispositifs à un électron (SET) capables de générer un courant continu directement proportionnel à une fréquence et la charge élémentaire, couplés à un amplificateur de courant très performant, le comparateur cryogénique de courant (CCC), devient pertinente pour réaliser un étalon quantique de courant. Dans ce contexte, les travaux ont été poursuivis au LNE sur l’étude de nouveaux dispositifs SET et le développement de nouveaux CCC. Durant cette thèse, un montage expérimental a été mis en place afin d’évaluer les performances d’un nouveau CCC, constitué d’une conception originale et de 30 000 tours. Les résultats expérimentaux obtenus sont satisfaisant par rapport aux objectifs fixés, que ce soit en termes de résolution en courant, d’erreurs, de stabilité des mesures et de reproductibilité. Le CCC développé durant la thèse peut donc être utilisé pour quantifier de manière métrologique les dispositifs à un électron. De plus, une modélisation réalisée à partir d’un schéma électrique équivalent a été mis en place afin de simuler le comportement réel du CCC en prenant en compte les aspects magnétiques et électriques mis en jeu. Cette simulation a permis la quantification de l’erreur due aux fuites de courants au travers des capacités parasites entourant les enroulements. Les résultats de la simulation indiquent que cette erreur atteint 10 10 à la fréquence de travail, ce qui est inférieure de deux ordres de grandeurs à l’erreur maximale tolérable : 10-8. Les résultats expérimentaux et de modélisation fournissent de nouveaux éléments d’amélioration de la conception de CCCs de grand gain. Enfin, la modélisation développée, une fois insérée dans une routine d’optimisation, pourra aussi être un outil de conception des CCCs très utile. / In a context of growing need of precision in measuring low currents for national metrology institutes, industry, instrument manufacturers and fundamental physics, study of single-electron tunneling (SET) devices capable of generating a direct current directly proportional to the frequency and the elementary charge, coupled with a high performance current amplifier, the cryogenic current comparator (CCC), becomes relevant to realize a quantum current standard. In this framework, at LNE, study of new SET devices and the development of CCCs continues. In this thesis, an experimental setup was implemented to evaluate the performance of a new CCC, consisting of a new design and 30 000 turns. The experimental results fulfill our goals, whether in terms of current resolution, errors, measurement stability and reproducibility. The CCC developed during the thesis can thus be used to metrologically quantify SET devices. In addition, a model based on an equivalent circuit diagram has been developed to simulate the actual behavior of the CCC, taking into account the magnetic and electrical aspects involved. This simulation allows the quantification of the error due to currents leakage through parasitic capacitances surrounding the windings. Results of the simulation indicate that this error reaches 10 10, which is less, by two orders of magnitude, than the maximum tolerable error: 10 8. Results obtained experimentally and by simulation provide new improvement elements in the design of high ratio CCCs. The developed model, once inserted into an optimization routine, can also be a very useful design tool of CCCs.

The thesis is focused on the research and development of a new hybrid one-wire bus with special use enabling microelectronic integration. The bus, its physical layer and protocol have been developed based on applied research to meet the complex requirements of a new application group. These requirements are especially laid on the bus robustness and its immunity to interference and to work under real operating conditions. Part of the thesis is a description of existing solutions of one-wire buses, definition of current solutions and setting of goals for research of the new bus. Further are made the design of protocol and operating parameters of the bus operating in low power and power mode. In conclusion, the thesis deals with the practical verification of the proposed solution and there is also suggested a perspective of follow-up research in this area.

<p>U ovoj doktorskoj disertaciji prikazana je koncepcija, realizacija i potvrda nove metode<br />jednovremenog etaloniranja strujnih mernih transformatora sa dve različite merne<br />aparature. Pregledom stručne literature ne postoji podatak da je ova metoda ranije<br />primenjivana. U disertaciji su prikazane različite merne metode za ispitivanje i<br />etaloniranje mernih transformatora koje imaju primenu u savremenoj praksi i koje<br />podrazumevaju i različite merne mogućnosti. Takođe je i ekperimentalno potvrđeno<br />jednovremeno ispitivanje i etaloniranje strujnih mernih transformatora sa nekoliko<br />mernih aparatura koje su zasnovane na različitim metodama. Sprovedna istraživanja i<br />eksperimentalni rezultati pokazuju i potvrđuju niz prednosti ovakvog načina<br />etaloniranja. Detaljna analiza komponenti merne nesigurnosti pokazala je da se<br />primenom ove metode postiže poboljšanje merne nesigurnost etaloniranja za skoro red<br />veličine u odnosu na klasično pojedinačno etaloniranje sa dve različite merne<br />aparature. Analiza uticajnih veličina na mernu nesigurnost pokazuje da se po ovoj novoj<br />metodi etaloniranja eliminiše niz komponenti od kojih su najznačajnije: uticaj<br />nejednakosti referentnih struja i ispitnog opterećenja. Istraživanja su takođe pokazala<br />da jednovremena metoda osim što doprinosi podizanju tačnosti etaloniranja strujnih<br />transformatora, ima primenu i u etaloniranju mernih aparatura za ispitivanje tačnosti<br />mernih transformatora i interkonparaciji strujnih etalon transformatora. Kroz<br />konkretne primere realizovane u praksi, razmotreni su i prikazani načini etaloniranja<br />mernih aparatura za ispitivanje tačnosti ovom novom metodom. Interkomparacijom dva<br />merna sistema visoke klase tačnosti Nacionalnog merološkog instituta Kanade<br />(National Research Council Canada), od kojih je jedna razvijena u Elektrotehničkom<br />Institutu &quot;Nikola Tesla&quot;, pokazana je i prednost primene jednovremene metode u oblasti<br />primarne metrologije strujnih mernih transformatora.</p> / <p>The dissertation presents the concept, its realisation and verification of the new method<br />of simultaneous comparison of the current transformers by two different measuring<br />apparatus. It is shown by searching the literature, that this method has not been used<br />before. In this dissertation different measuring methods for testing and calibration of<br />current transformers, with their different measuring capabilities are presented. Most of<br />them have been used in recent practice. Furthermore, the experimental verification of<br />new simultaneous calibration method is presented. For this reason some measuring<br />apparatus based on different measuring methods were used. Conducted research and<br />experimental results confirmed a number of advantages of this calibration method.<br />Detailed analysis of the components of the uncertainty of measurements shown that<br />using simultaneous method uncertainty of measurements have been improved<br />comparing to method with two individual calibration by different apparatus. In that case<br />some of the measuring uncertainty components can be neglected. The most significant<br />is component caused by variation of referent current and component caused by variation<br />of burden. The research has also showed that simultaneous method can be used for<br />calibration of measuring apparatus for current transformer accuracy testing and their<br />inter-comparisons. The ways of calibration of apparatus for current transformer accuracy<br />testing are considered and presented, through concrete examples realized in practice.<br />A high-accuracy comparison of two NRC (National Research Council Canada)<br />calibration systems were carried out by new simultaneous method. One measuring<br />system is developed at Electrical Engineering institute Nicola Tesla, Belgrade.<br />Accordingly the advantage of simultaneous method applied at the primary metrology of<br />current transformer is verified.</p>