Étude et conception des circuits de puissance CMOS RF et nouvelles fonctionnalités de modulation pour des applications de communication

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.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

Circuit design and technological limitations of silicon RFICs for wireless applications

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. 201-206).Semiconductor technologies have been a key to the growth in wireless communication over the past decade, bringing added convenience and accessibility through advantages in cost, size, and power dissipation. A better understanding of how an IC technology affects critical RF signal chain components will greatly aid the design of wireless systems and the development of process technologies for the increasingly complex applications that lie on the horizon. Many of the evolving applications will embody the concept of adaptive performance to extract the maximum capability from the RF link in terms of bandwidth, dynamic range, and power consumption-further engaging the interplay of circuits and devices is this design space and making it even more difficult to discern a clear guide upon which to base technology decisions. Rooted in these observations, this research focuses on two key themes: 1) devising methods of implementing RF circuits which allow the performance to be dynamically tuned to match real-time conditions in a power-efficient manner, and 2) refining approaches for thinking about the optimization of RF circuits at the device level. Working toward a 5.8 GHz receiver consistent with 1 GBit/s operation, signal path topologies and adjustable biasing circuits are developed for low-noise amplifiers (LNAs) and voltage-controlled oscillators (VCOs) to provide a facility by which power can be conserved when the demand for sensitivity is low. As an integral component in this effort, tools for exploring device level issues are illustrated with both circuit types, helping to identify physical limitations and design techniques through which they can be mitigated.(cont.) The design of two LNAs and four VCOs is described, each realized to provide a fully-integrated solution in a 0.5 tm SiGe BiCMOS process, and each incorporating all biasing and impedance matching on chip. Measured results for these 5-6GHz circuits allow a number of poignant technology issues to be enlightened, including an exhibition of the importance of terminal resistances and capacitances, a demonstration of where the transistor fT is relevant and where it is not, and the most direct comparison of bipolar and CMOS solutions offered to date in this frequency range. In addition to covering a number of new circuit techniques, this work concludes with some new views regarding IC technologies for RF applications.by Donald A. Hitko.Ph.D

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Electronic warfare self-protection of battlefield helicopters : a holistic view

The dissertation seeks to increase understanding of electronic warfare (EW) self-protection (EWSP) of battlefield helicopters by taking a holistic (systems) view on EWSP. It also evaluates the methodologies used in the research and their suitability as descriptive tools in communication between various EWSP stakeholders. The interpretation of the term "holistic view" is a central theme to the dissertation. The research methodology is bottom-up – which is necessary since no previous work exists that could guide the study – and progresses from analysis to synthesis. Initially several methods are evaluated for presenting findings on EWSP, including high-level system simulation such as Forrester system dynamics (FSD). The analysis is conducted by a comprehensive literature review on EW and other areas that are believed to be of importance to the holistic view. Combat scenarios, intelligence, EW support, validation, training, and delays have major influence on the effectiveness of the EWSP suite; while the initial procurement decision on the EWSP suite sets limits to what can be achieved later. The need for a vast support structure for EWSP means that countries with limited intelligence and other resources become dependent on allies for support; that is, the question of EWSP effectiveness becomes political. The synthesis shows that a holistic view on EWSP of battlefield helicopters cannot be bounded in the temporal or hierarchical (organizational) senses. FSD is found to be helpful as a quality assurance tool, but refinements are needed if FSD is to be useful as a general discussion tool. The area of survivability is found to be the best match for the holistic view – for an EWSP suprasystem. A global survivability paradigm is defined as the ultimate holistic view on EWSP. It is suggested that future research should be top-down and aiming at promoting the global survivability paradigm. The survivability paradigm would give EWSP a natural framework in which its merits can be assessed objectively.reviewe