Orientadores: Evandro Conforti, Cristiano de Melo Galle / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-07T05:52:16Z (GMT). No. of bitstreams: 1 Ribeiro_NapoleaodosSantos_M.pdf: 3461536 bytes, checksum: a62ed88dd69c1d4ba69dd6875b34f001 (MD5) Previous issue date: 2006 / Resumo: A utilização de redes ópticas com multiplexação de comprimento de onda (WDM) é uma solução para o aumento na taxa de transferência de dados em sistemas de telecomunicações. Para um bom funcionamento de tais redes, a utilização de um conversor em comprimento de onda com amplificador óptico a semicondutor é importante, pois facilita o processamento totalmente no domínio óptico, bem como uma maior flexibilidade na utilização de sinais em diferentes comprimentos de onda. Desta forma, apresenta-se, neste trabalho, um estudo de um conversor em comprimento de onda via modulação cruzada de ganho baseado em um amplificador óptico a semicondutor (SOA). Um estudo teórico do SOA e do conversor é apresentado, seguindo-se do estudo de montagens experimentais que permitem a obtenção de bons resultados para a conversão, comprovados com a comparação com resultados simulados. Para a realização da simulação, são estudados certos parâmetros e a relação destes com a conversão. Os resultados apresentados neste trabalho estão coerentes com os da literatura especializada. Melhorias no desempenho do conversor são apresentadas, bem como sugestões para trabalhos futuros / Abstract: The use of wavelenght-division multiplex (WDM) optical networks is a solution for the data-rate increasing in telecommunications systems. For a good performance of such networks, the use of wavelength converter based on semiconductor optical amplifier is important, since this one allows all-optical signal processing, as well as more flexibility in the spectral use of optical signals, assigned at different wavelengths. Therefore, the study of wavelength converters based on cross-gain modulation of semiconductor optical amplifier (SOA) is presented. The SOA and its converter¿s theoretical study are presented, followed by the experimental set-up for the conversion, and last by the comparison with simulated results. For simulation procedures, the study of certain parameters and its relation to conversion efficiency is carried out. Performance improvements in the converter operation are presented as well as indications for further works / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Esta dissertação apresenta o projeto de um amplificador de baixo ruído (LNA) para aplicação em 2,4 GHz na tecnologia CMOS 0,35 µm. A metodologia baseia-se na obtenção das dimensões dos dispositivos do circuito considerando o consumo de potência e o desempenho em relação ao ruído. Os resultados mostram que a metodologia implementada é eficaz no projeto de um LNA quando se comparam os resultados obtidos nos cálculos com os resultados obtidos no simulador. A expressão de corrente que considera canal curto impõe maior precisão nos resultados, pois se aplica o ajuste de curva com a curva de corrente obtida pelo simulador. Isto permite maior precisão nos resultados dos cálculos de ruído. O fluxo do projeto baseia-se na implementação de dispositivos ideais obtidos de projeto com o propósito de fazer-se comparações dos resultados de cálculos com as simulações, então, usa-se dispositivos reais e ajusta-se o circuito para encontrar melhores desempenhos quanto às especificações. Os resultados mostram a necessidade de ajuste do circuito quando inserido o modelo do indutor para que se consiga desempenhos próximos dos obtidos inicialmente. Em seguida, realiza-se o layout do circuito e sua extração parasitária para fins de fabricação. Verifica-se que a metodologia apresentada é capaz de direcionar a um projeto de um LNA na tecnologia com resultados finais satisfatórios de ganho, ruído e consumo. Assim os resultados esperados são 14,66 dB de ganho, 1,9 dB de fator de ruído e 2,99 mA de consumo de corrente (9,87 mW em 3,3 V de alimentação) ambos no primeiro estágio. / This work presents the design of a low-noise amplifier (LNA) for application at 2.4 GHz using CMOS 0.35 µm technology. The methodology is based on obtaining the dimensions of the devices taking into account of power consumption and performance on noise. Results show that the implemented methodology is efficient in the design of LNAs when it compares results obtained by calculation and simulation. The expression of current that considers short-channel effects increases the precision of results because curve fitting is applied with the current of the simulator. This permits precision on the results of the noise calculation. The design-flow firstly bases on implementation of ideal devices obtained by design on purposes of doing comparisons between calculated and simulated results, then real devices is used and the circuit is fixed to find better performance regarding the specifications. The results showed the necessity of adjusts in the circuit when the inductor is inserted to reach a closer initial performance. Afterwards, the layout of the circuit and its parasitic extraction are worked out for purposes of fabrication. It is verified that this methodology is capable of directing to the design of LNAs using the proposed technology with satisfactory final results of gain, noise and power consumption. Therefore, the expected results are 14,66 dB of gain, 1,9 dB of noise figure, 2,99 mA of current consumption (9,87 mW within 3.3 V of supply voltage) both of them at first stage.

Radar warning systems are life saving equipment in modern fighter aircraft. It is therefore vital that the system can tell the difference between a threat genuine frequency) and a false signal (spurious frequency). This thesis presents a model aimed at predicting the frequencies and other parameters in the RF converter of the radar warning system. The components of the RF converter have been studied, measured, and modelled. The modelling tool has been the Simulink toolbox for Matlab. Extreme accuracy has been sacrificed in order to make the model easy to use for the working engineer. Instead, this model presents a rough estimate of some of the most important properties of the radar warning system with just a few data sheet figures as input. The simulation results are satisfactory as a whole. Simulink is the limiting factor in the implementation of the model. Significantly improved results can probably be obtained by working in another software environment.

In this thesis, a new way of using predisortion for linearization of power amplifiers is evaluated. In order to achieve an adequate power level for the jamming signal, power amplifiers are used in military jamming systems. Due to the nonlinear characteristic of the power amplifier, distortion will be present at the output. As a consequence, unwanted frequencies are subject to jamming. To decrease the distortion, linearization of the power amplifier is necessary. In the system of interest, a portion of the distorted power amplifier output signal is fed back. Using this measurement, a predistortion signal is synthesized to allow suppression of the unwanted frequency components. The predistortion signal is updated a number of times in order to achieve a good outcome. Simulations are carried out in Matlab for testing of the algorithm. The evaluation of the new linearization technique shows promising results and that good suppression of distortion components is achieved. Furthermore, new predistortion features are possible to implement, such as predistorsion in selected frequency bands. However, real hardware testing needs to be carried out to confirm the results.

This thesis discusses the design, construction and testing of a highefficiency, 100 MHz, 1 kW, Class-E solid state power amplifier. The design was performed with the aid of computer simulations using electronic design software (ADS). The amplifier was constructed around Ampleon's BLF188XR LDMOS transistor in a single ended design. The results for 100 MHz operation show a power added efficiency of 82% at 1200 W pulsed power output. For operation at 102 MHz results show a power added efficiency of 86% at 1050 W pulsed power output. Measurements of the drain- and gate voltage waveforms provide validation of Class-E operation.

Les signaux des nouveaux standard de communications (LTE) ont une grande différence entre la puissance maximale et moyenne (PAPR), cela n'est pas favorable pour l'utilisation dans les amplificateurs conventionnels vu qu'ils présentent un rendement maximale seulement quand ils travaillent au niveau de puissance maximale. Des amplificateurs de puissance Doherty pour présenter une efficacité constante pour une large gamme de puissance constituent une solution favorable à ce problème. Ce travail présente la méthodologie de conception et des résultats de mesure d'un amplificateur de puissance Doherty entièrement intégré dans la technologie 65 nm CMOS avec une constante PAE sur un 7 dB de plage de puissance. Mesures de 2,4 GHz à 2,6 GHz montrent des performances constantes PAE à partir du niveau de 20% jusqu'à 24% avec une puissance de sortie maximale de 23,4 dBm. Le circuit a été conçu avec une attention particulière pour le faible coût. / The signals of the new communication standards (LTE) show a great difference between the peak and its average power (PAPR) being unsuitable for use with conventional power amplifiers because they present maximum efficiency only when working with maximum power. Doherty power amplifiers for presenting a constant efficiency for a wide power range represent a favorable solution to this problem. This work presents the design methodology and measurements results of a fully integrated Doherty Power Amplifier in 65 nm CMOS technology with constant PAE over a 7 dB backoff. Measurements from 2.4 GHz to 2.6 GHz show constant PAE performance starting in 20% level up to 24% with a maximum output power of 23.4 dBm.The circuit was designed with special attention to low cost.

Dans l’ère des systèmes de communication multi-standards, le besoin des circuits en radio fréquence (RF) flexibles et reconfigurables pousse l´industrie et le monde académique vers la recherche d´architectures alternatives d’émetteurs et de récepteurs RF. Dans cette thèse, nous nous intéressons aux émetteurs RF flexibles. Nous présentons une architecture basée sur l’utilisation d’un oscillateur de puissance composé d´un amplificateur de puissance dans une boucle de rétroaction positive. Pour des raisons de compatibilité avec des circuit numériques et dans le but de minimiser les coûts de fabrication, nous avons choisi la technologie CMOS. Ce choix génère des difficultés de conception des circuits en RF à cause des faibles tensions de claquage. Cette contrainte de conception a motivé le choix de la classe EF2 pour l’amplificateur de puissance afin de réduire le stress en tension sur les transistors. Nous présentons la conception de cet amplificateur de puissance de classe EF2, ainsi que la conception de l’oscillateur de puissance. Nous validons cette architecture avec une implémentation en technologie CMOS 0.13um de STMicroelectronics. Nous démontrons le bon comportement par une campagne de mesures des circuits fabriqués. Ce circuit répond aux contraintes de flexibilité de modulation et de puissance de sortie. Il peut donc être utilisé pour différents standards de communications. Les limitations inhérentes de cette architecture sont discutées et une modélisation mathématique est présentée. / This work presents the study, design and measurement of RF circuits aiming communication applications. The need for flexible and reconfigurable RF hardware leads to the need of alternative transmitter architectures. In the center of this innovative architecture, there is thepower oscillator. This circuit is composed of a power amplifier in a positive feedback loop soit oscillates. As the circuit under study is mainly composed of a power amplifier, a study on power amplifier is mandatory. Modern CMOS technologies impose difficulties in the efficient RF generation due to low breakdown voltages. In order to reduce the voltage stress on the transistors, wave form-engineering techniques are used leading to the use of class EF2. Thedesign and measurement of a class EF2 power amplifier and power oscillator are shown. Thecircuits were implemented in standard STMicroelectronics 0.13um CMOS. Correct behaviorfor the circuits was obtained in measurement, leading to a first implementation of class EF2 inRF frequencies. From a system perspective, the proposed architecture is shown to be flexible and able to generate different modulations without change in the hardware. Reconfigurability is shown not only in modulation but also in output power level. The limitations of this architecture are discussed and some mathematical modeling is presented.

Este informe técnico propone el diseño de un bloque llamado Amplificador Limitador que se encuentra en los equipos que trabajan con fibra óptica o con altas tasas de transmision de datos y que estan integrados en una pastilla de silicio. El objetivo principal es aumentar el ancho de banda de un Amplificador Limitador mediante la aplicación de la técnica Inductive Peaking para lograr velocidades que corresponden a una portadora óptica OC-192 equivalente a 10 Gbps bajo el estándar SONET. Haciendo uso de tecnología CMOS con transistores de 130 nm de ancho de canal. A su vez se propone disminuir el consumo de potencia y el área ocupada en la pastilla de Silicio utilizando inductores activos y la eliminación de los capacitores de desacople DC entre etapas. Los resultados finales Post Layout demuestran que es posible extender el ancho de banda con las técnicas mencionadas anteriormente, reducir el consumo total y el área ocupada en la pastilla de Silicio y cumplir con las especificaciones técnicas requeridas. This technical report proposes the design of a block called Limiting Amplifier which is found in equipment that works with optical fiber or with high rates of data transmission and that are integrated in a silicon wafer. The main objective is to increase the bandwidth of a limiter amplifier by applying the Inductive Peaking technique to achieve speeds that correspond to an OC-192 optical carrier equivalent to 10 Gbps under the SONET standard, making use of CMOS technology with 130 nm channel width transistors. At the same time, it is proposed to reduce the power consumption and the area occupied in the chip using active inductors and the elimination of DC decoupling capacitors between stages. The final results of Post Layout show that it is possible to extend the bandwidth with the techniques mentioned above, reducing the total consumption and the area occupied in the silicon pellet and accomplishing with the required technical specifications.

Cette thèse s’inscrit dans le domaine de l’amplification de puissance microonde linéaire et haut rendement en technologie GaN. Le premier chapitre décrit le contexte général de l’émission de signaux microondes de puissance pour les télécommunications sans fil, avec un focus particulier apporté sur l’amplificateur de puissance RF. Les différents critères de linéarité et d’efficacité énergétique sont introduits.Le second chapitre présente plus particulièrement la technologie GaN et le transistor de puissance comme brique de base pour l’amplification de puissance microonde. Une revue synthétique des différentes architectures relevées dans la littérature relative à l’amplification à haut rendement est faite.En troisième chapitre, le banc de mesure temporelle d’enveloppe développé et servant de support expérimental à cette étude est présenté. Les procédures d’étalonnage et de synchronisation sont décrites. En illustration, une nouvelle méthode de mesure du NPR large bande est présentée, et validée expérimentalement.Une solution d’amplification adaptative innovante est étudiée dans le quatrième chapitre, et constitue le cœur de ce mémoire. Celle-ci se base sur le contrôle dynamique de la polarisation de grille autour du point de pincement, au rythme de l’enveloppe de modulation. Un démonstrateur d’amplification 10W GaN en bande S (2.5GHz) est développé. Comparativement à la classe B fixe, une forte amélioration de la linéarité est obtenue, sans impact notable sur le rendement moyen de l’amplificateur RF. Finalement, une investigation de la technique proposée pour l’amélioration du rendement du modulateur dans l’architecture d’envelope tracking de drain est menée. / This work deals with linear and high efficiency microwave power amplification in GaN technology.The first chapter is dedicated to the general context of wireless telecommunication with a special emphasis on the RF power amplifier. The most representative figures of merit in terms of linearity and power efficiency are introduced.The second chapter deals more specifically with the GaN technology and GaN-based transistor for microwave power amplification. A description of the principal architectures found in the literature related to high efficiency and linear amplification is summarized.In the third chapter, the developed envelope time-domain test bench is presented. Time-synchronization and envelope calibration procedures are discussed. As an illustration, a new specific wideband NPR measurement is presented and experimentally validated.An innovative power amplifier architecture is presented in the fourth chapter. It is based on a specific dynamic gate biasing technique of the power amplifier biased close to the pinch-off point. A 10W GaN S-band demonstrator has been developed. Compared to fixed class-B conditions, a linearity improvement has been reported without any prohibitive efficiency degradation of the RF power amplifier. Finally, an investigation of the proposed technique for the efficiency improvement in the drain envelope tracking technique is proposed.

Les fibres multimodales ont longtemps été délaissées en raison des distorsions temporelles et spatiales subies par la lumière au cours de sa propagation dans la fibre. Ces distorsions sont les conséquences des couplages modaux et de la disparité des temps de propagation des modes de fibre. Bien que complexe, la propagation dans un guide multimodal reste déterministe et peut être maitrisée par une structuration cohérente de l’excitation. La manipulation d’ondes en présence de gain dans la fibre optique, au coeur de ces travaux de thèse, constitue une problématique plus complexe encore puisque la carte de saturation des modes hétérogène rend la propagation non linéaire. Deux types d’amplificateurs multimodaux à fibre dopée ytterbium ont été étudiés : une fibre à saut d’indice à large coeur et une fibre à coeurs multiples couplés. Le contrôle spatial du faisceau transmis est obtenu en structurant le front d’onde incident à l’aide d’un miroir déformable couplé à un algorithme itératif. En régime d’excitation continue, cette technique de contrôle adaptatif, robuste et rapide a permis de focaliser le rayonnement en extrémité de fibre sur des spots uniphases, malgré les couplages modaux, l’hétérogénéité de gain modal et la saturation du gain. Il a aussi été démontré que la mise en forme du front d’onde incident ne réduisait pas le gain d’amplification. Une puissance de 2,8 W a été confinée dans un unique spot avec un gain de12 dB. Des structures intensimétriques plus complexes de type « multispots » ont également été obtenues. Enfin, la focalisation à travers la fibre amplificatrice a été réalisée avec succès en régime femtoseconde pour lequel la propagation s’accompagne de couplages spatio-temporels. Une première démonstration de principe a permis d’obtenir 120 kW de puissance crête avec un gain de 14 dB dans une impulsion uniquement limitée par la dispersion chromatique (350 fs), le profilage spatial permettant aussi de contrôler l’impulsion amplifiée par la sélection de modes dont les vitesses de groupe sont proches. / For a long time, multimode fibers were sparsely investigated because of the spatial and temporal distortions occurring during propagation across the fiber. Those distortions are consequences of mode coupling and modal propagation constant disparity. Although the propagation in a multimode waveguide is complex, it is deterministic and can be controlled by spatial shaping of the excitation. Considering an amplifying medium, the problem, at the heart of this thesis, is more complex because of nonlinear propagation due to heterogeneous gain saturation. Two kinds of Ytterbium doped multimode fiber amplifiers were tested: a step index fiber with a large core diameter and a coupled core multicore fiber. Spatial control of the output of the amplifier was achieved using a deformable mirror in combination with an iterative algorithm. In the case of a continuous wave excitation of the amplifier, we demonstrated that it was possible to confine light in a single-phase spot with a 2,8 W average power and 12 dB gain. We also demonstrated that the spatial shaping of the output has no effect on the amplifier gain. Furthermore, we obtained more complex output fields of multi-spot structure. Finally, focalization through the amplifying fiber was successfully demonstrated in femtosecond regime for which spatio-temporal couplings occur. A 120 kW peak power spot with a gain of 14 dB in a 350 fs pulse was obtained in a first experimental proof of concept. The spatial shaping allows also to control the duration of the amplified pulse by selection of modes with close group velocities.