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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.
11

Low Voltage Active Inductor Low Noise Amplifier

Xi Pond, Jun 23 July 2012 (has links)
This paper is the use of the active inductor instead of passive inductors to save area, enter the match aspects of the use of the feedback capacitor in parallel with the resistor to achieve matching with the control input voltage, in addition to adjusting the feedback resistor can control the noise. The LNA dissipates 13.2 mW power and achieves input return loss (S11) below -10dB, output return loss (S22) below -10 dB, forward gain (S21) of 11.3~14.5dB, reverse isolation (S12) below -40dB, and noise figure (NF) of 3~3.18 dB. 1-dB compression point (P1dB) of -24 dBm and input third-order inter-modulation point (IIP3) of -14 dBm .
12

High efficiency switching CMOS power amplifiers for wireless communications

Lee, Ockgoo 13 November 2009 (has links)
High-efficiency performance is one of the most important requirements of power amplifiers (PAs) for wireless applications. However, the design of highly efficient CMOS PAs for watt-level applications is a challenging task. This dissertation focuses on the development of the design method for highly efficient CMOS PAs to overcome the fundamental difficulties presented by CMOS technology. In this dissertation, the design method and analysis for a high-power and highefficiency class-E CMOS PA with a fully integrated transformer have been presented. This work is the first effort to set up a comprehensive design methodology for a fully integrated class-E CMOS PA including effects of an integrated transformer, which is very crucial for watt-level power applications. In addition, to improve efficiency of cascode class-E CMOS PAs, a charging acceleration technique is developed. The method accelerates a charging speed to turn off the common-gate device in the off-state, thus reducing the power loss. To demonstrate the proposed cascode class-E PA, a prototype CMOS PA was implemented in a 0.18-μm CMOS process. Measurements show an improvement of approximately 6% in the power added efficiency. The proposed cascode class-E PA structure is suitable for the design of high-efficiency class-E PAs while it reduces the voltage stress across the device.
13

Characterization and Failure Mode Analysis of Cascode GaN HEMT

Liu, Zhengyang 16 July 2014 (has links)
Recent emerging gallium nitride (GaN) high electron mobility transistor (HEMT) is expected to be a promising candidate for high frequency power conversion techniques. Due to the advantages of the material, the GaN HEMT has a better figure of merit (FOM) compared to the state-of-the-art silicon (Si) power metal oxide silicon field effect transistor (MOSFET), which allows the GaN HEMT to switch with faster transition and lower switching loss. By applying the GaN HEMT in a circuit design, it is possible to achieve high frequency, high efficiency, and high density power conversion at the same time. To characterize the switching performance of the GaN HEMT, an accurate behavior-level simulation model is developed in this thesis. The packaging related parasitic inductance, including both self-inductance and mutual-inductance, are extracted based on finite element analysis (FEA) methods. Then the accuracy of the simulation model is verified by a double-pulse tester, and the simulation results match well with experiment in terms of both device switching waveform and switching energy. Based on the simulation model, detailed loss breakdown and loss mechanism analysis are made. The cascode GaN HEMT has high turn-on loss due to the body diode reverse recovery of the low voltage Si MOSFET and the common source inductance (CSI) of the package; while the turn-off loss is extremely small attributing to the cascode structure. With this unique feature, the critical conduction mode (CRM) soft switching technique are applied to reduce the dominant turn on loss and increase converter efficiency significantly. The switching frequency is successfully pushed to 5MHz while maintaining high efficiency and good thermal performance. Traditional packaging method is becoming a bottle neck to fully utilize the advantages of GaN HEMT. So an investigation of the package influence on the cascode GaN HEMT is also conducted. Several critical parasitic inductors are identified, which cause high turn on loss and high parasitic ringing which may lead to device failure. To solve the issue, the stack-die package is proposed to eliminate all critical parasitic inductors, and as a result, reducing turn on loss by half and avoiding potential failure mode of the cascode GaN device effectively. Utilizing the proposed stack-die package and ZVS soft switching, the GaN HEMT high frequency, high efficiency, and high density power conversion capability can be further extended to a higher level. / Master of Science
14

Développement de transistor AlGaN/GaN E-mode sur substrat silicium 200 mm compatible avec une salle blanche CMOS / Development of AlGaN/GaN E-mode transistors on 200 mm silicon substrate compatible with CMOS clean room

Barranger, Damien 20 December 2017 (has links)
La thèse porte sur le développement de composants à base d’hétérojonction AlGaN/GaN. Cette hétérojonction permet de bénéficier d’une excellente mobilité (2000 cm²/V.s) grâce à l’apparition d’un gaz d’électron dans le GaN. Cependant, les composants fabriqués sur cette hétérojonction sont normally-on. Pour des raisons de sécurité et d’habitude de conception des composants normally-off sont nécessaires. Il existe de nombreuses façons de fabriquer des transistors normally-off à base d’hétérojonction AlGaN/GaN, dans cette thèse nous avons choisi d’étudier un MOSCHEMT, cette structure est caractérisée par une grille de type MOS et des accès de type HEMT possédant les excellentes propriétés de l’hétérojonction, en fonction des paramètres technologiques : épitaxie, process et structure des composants. L’une des variations technologiques étudiées est une structure cascodée permettant d’améliorer les performances à l’état passant sans détériorer la caractéristique en blocage des composants. L’objectif est de concevoir un composant normally-off sur substrat silicium 200 mm avec une tension de seuil supérieure à 1V, pouvant tenir 600 V en blocage, avec un calibre en courant entre 10 A et 30 A et compatible en salle blanche CMOS. Le manuscrit comporte quatre chapitres. Grâce à une étude bibliographique, le premier chapitre présente les différentes méthodes permettant d’obtenir un transistor normally-off à base de nitrure de gallium. Ce chapitre présente et justifie le choix technologique du CEA-LETI. Le deuxième chapitre présente les modèles ainsi que les méthodes de caractérisations utilisés au cours de la thèse. Le troisième chapitre traite des résultats obtenus en faisant varier les paramètres de fabrication sur les MOSC-HEMT. Enfin, le quatrième chapitre montre une étude sur une technologie innovante de type cascode. Cette structure doit permettre d’augmenter la tension de claquage des transistors sans détériorer l’état passant. / This thesis focuses on the development of AlGaN/GaN heterojunction components or HEMT. This heterojunction has an excellent mobility (2000 cm² / V.s) thanks to the appearance of an electron gas in the GaN. However, the components made with this heterojunction are normally-on. For safety reasons particularly, normally-off components are required. There are many ways to make normally-off transistors based on AlGaN/GaN heterojunction. In this thesis we chose to study a MOSCHEMT strucutre. This structure is characterized by a MOS type gate and HEMT type accesses. The study shows the effects of technological parameters (epitaxy, process and component structure) on the electrical behaviour of the components. Another structure studied is the monolithic cascode, which can improve on-state performance of the MOSC-HEMT without damaging the characteristic in reverse of the components. The objective of this thesis is to design a normally-off component on silicon substrate 200 mm with a threshold voltage higher than 1V, able to hold 600 V in reverse, with a current rating between 10 A and 30 A and compatible in CMOS clean room. The manuscript has four chapters. Through a bibliographic review, the first chapter presents the different methods to obtain a normally-off transistor based on gallium nitride. This chapter presents and justifies the technological choice of CEA-LETI. The second chapter presents the models as well as the methods of characterizations used during the thesis. The third chapter deals with the results obtained by varying the manufacturing parameters on the MOSC-HEMTs. Finally, the fourth chapter shows a study on innovative cascode technology. This structure must make it possible to increase the breakdown voltage of the transistors without damaging the on state.
15

Low Voltage Current Conveyor Design Techniques / Techniky návrhu nízkonapěťových proudových konvejorů

El Dbib, Issa January 2008 (has links)
Disertační práce se zabývá proudovými konvejery CCII v proudovém modu s nízkým napájecím napětím. Potřeba velké rychlosti, vysokého výkonu a nízkého napájecího napětí pro mobilní elektroniku a komunikační systémy a potíže se současným stavem tlačí analogové návrháře k nalezení obvodové architektury a nové nízkopříkonové techniky. Je zde podrobně rozebrána technika složené kaskody a substrátu řízeného tranzistoru, která pomáhá produkci nízkopříkonových nízkovoltových obvodů. Dále jsou rozebrány a diskutovány základní funkční bloky, jako jsou proudová zrcadla, diferenční zesilovače a další, schopné pracovat při nízkých napájecích napětích. Jádrem práce je návrh konvejerů typu CCII s nízkým napájecím napětím. Jsou rozebrány jejich výhody a srovnání s konvenčními obvody. Princip a implementace operačního zesilovače založeného na proudovém konvejeru CCII je v práci navržen a popsán.
16

Design of SiGe HBT power amplifiers for microwave radar applications

Andrews, Joel 19 February 2009 (has links)
A novel modification to the standard cascode amplifier architecture is presented in SiGe which allows for an optimal separation of gain and breakdown functions through the mixed breakdown cascade architecture, opening the door for moderate power amplifiers in SiGe. Utilizing this technique, a two-stage, high-gain amplifier operating at X-Band is fabricated and measured. The 20 dB of gain per stage represents the highest gain at X-Band at the time of publication. Additionally, a near one Watt power amplifier is designed and fabricated at X-Band, which represents the highest output power in SiGe at X-Band at time of publication. Related to the power amplifier design, thermal considerations are also investigated. The validity of utilizing lumped mutual thermal coupling in SiGe devices is presented. Using this finding, a thermal coupling model and network which are compliant for use with commonly available HBT models and circuit simulators is presented. This model and network is used to thermally optimize SiGe PA cells based upon layout spacing.
17

Návrh operačního zesilovače CMOS / Design of operational amplifier CMOS

Navrátil, Jakub January 2009 (has links)
The present work deals with issues of a design of operational transconductance amplifier in technology CMOS AMIS 0,7 um. The aim of the work is to design a accurate operational amplifier with a low input differential voltage.
18

A Design Basis for Composite Cascode Stages Operating in the Subthreshold/Weak Inversion Regions

Waddel, Taylor Matt 28 January 2012 (has links) (PDF)
Composite cascode stages have been used in operational amplifier designs to achieve ultra-high gain at very low power. The flexibility and simplicity of the stage makes it an appealing choice for low power op-amp designs. Op-amp design using the composite cascode stage is often made more difficult through the lack of a design process. A design process to aid in the selection of the MOSFET dimensions is provided in this thesis. This process includes a table-based method for selection of the widths and lengths of the MOSFETs used in the composite cascode stage. Equations are also derived for the gain, bandwidth, and noise of the composite cascode stage with each of the devices operating in the various regions of inversion.
19

Etude d'une nouvelle filière de composants sur technologie nitrure de gallium. Conception et réalisation d'amplificateurs distribués de puissance large bande à cellules cascodes en montage flip-chip et technologie MMIC.

Martin, Audrey 06 December 2007 (has links) (PDF)
Ces travaux de recherche se rapportent à l'étude de transistors HEMTs en Nitrure de Gallium pour l'amplification de puissance micro-onde. Une étude des caractéristique des matériaux grand gap et plus particulièrement du GaN est réaliséé afin de mettre en exergue l'adéquation de leurs propriétés pour les applications de puissance hyperfréquence telle que l'amplification large bande. Dans ce contexte, des résultats de caractérisations et modélisations électriques de composants passifs et actifs sont présentés. Les composants passifs dédiés aux conceptions de circuits MMIC sont décrits et différentes méthodes d'optimisation que ce soit au niveau électrique ou électromagnétique sont explicitées. Les modèles non linéaires de transistors impliqués dans nos conceptions sont de même détaillés. Le fruit de ces travaux concerne la conception d'amplificateurs distribués de puissance large bande à base de cellules cascode de HEMTs GaN, l'un étant reportés en flip-chip sur un substrat d'AlN, le second en technologie MMIC. La version MMIC permet d'atteindre 6.3W sur la bande 4-18GHz à 2dB de compression. Ces résultats révèlent les fortes potetialités attendues des composants HEMTs GaN.
20

Circuit and System Design for mm-wave Radar and Radio Applications

Sarkas, Ioannis 13 August 2013 (has links)
Recent advancements in silicon technology have paved the way for the development of integrated transceivers operating well inside the mm-wave frequency range (30 - 300 GHz). This band offers opportunities for new applications such as remote sensing, short range radar, active imaging and multi-Gb/s radios. This thesis presents new ideas at the circuit and system level for a variety of such applications, up to 145 GHz and in both state-of-the-art nanoscale CMOS and SiGe BiCMOS technologies. After reviewing the theory of operation behind linear and power amplifiers, a purely digital, scalable solution for power amplification that takes advantage of the significant ft/fmax improvement in pFETs as a result of strain engineering in nanoscale CMOS is presented. The proposed Class-D power amplifier, features a stacked, cascode CMOS inverter output stage, which facilitates high voltage operation while employing only thin-oxide devices in a 45 nm SOI CMOS process. Next, a single-chip, 70-80 GHz wireless transceiver for last-mile point-to-point links is described. The transceiver was fabricated in a 130 nm SiGe BiCMOS technology and can operate at data rates in excess of 18 Gbps. The high bitrate is accomplished by taking advantage of the ample bandwidth available at the W-band frequency range, as well as by employing a direct QPSK modulator, which eliminates the need for separate upconversion and power amplification. Lastly, the system and circuit level implementation of a mm-wave precision distance and velocity sensor at 122 and 145 GHz is presented. Both systems feature a heterodyne architecture to mitigate the receiver 1/f noise, as well as self-test and calibration capabilities along with simple packaging techniques to reduce the overall system cost.

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