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1

Muthukrishnan, Swaminathan. "ESD Protected SiGe HBT RFIC Power Amplifiers." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31705.

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Over the last few decades, the susceptibility of integrated circuits to electrostatic discharge (ESD) induced damages has justified the use of dedicated on-chip protection circuits. Design of robust protection circuits remains a challenging task because ESD failure mechanisms have become more acute as device dimensions continue to shrink. A lack of understanding of the ESD phenomena coupled with the increased sensitivity of smaller devices and time-to-market demands has led to a trial-and-error approach to ESD-protected circuit design. Improved analysis capabilities and a systematic design approach are essential to accomplish the challenging task of providing adequate protection to core circuit(s). The design of ESD protection circuitry for RFIC's has been relatively slow to evolve, compared to their digital counterparts, and is now emerging as a new design challenge in RF and high-speed mixed-signal IC development. Sub-circuits which are not embedded in a single System-on-Chip (SOC), such as RF Power amplifiers (PAs), are of particular concern as they are more susceptible to the various ESD events. This thesis presents the development of integrated ESD protection circuitry for two RFIC Power Amplifier designs. A prototype PA for 2.4 GHz Wireless Local Area Network (WLAN) applications was redesigned to provide protection to the RF input and the PA Control pins. A relatively new technique known as the L-C tank approach was used to protect the RFinput while a standard diode ring approach was used to protect the control line. The protection techniques studied were subsequently extended to a completely protected three-stage PA targeting 1.9 GHz Digitally Enhanced Cordless Telephone (DECT) applications. An on-chip shunt-L-series-C input matching network was used to provide ESD protection to the input pin of the DECT PA. A much more area efficient (as compared to the diode ring technique) Zener diode approach was used to protect the control and signal lines. The PA's RF performance was virtually unaffected by the addition of the protection circuits. Both PAs were designed in a commercially available 0.5 ìm SiGe-HBT process. The partially protected WLAN PA was fabricated and packaged in a 3mm x 3mm Fine Pitch Quad Flat Package FQFP-N 12 Lead package and had a measured ESD protection rating of ± 1kV standard Human Body Model (HBM) ESD test. The simulated DECT PA demonstrated +1.5kV/-4kV HBM performance.<br>Master of Science
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2

Raghunathan, Uppili Srinivasan. "TCAD modeling of mixed-mode degradation in SiGe HBTs." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54315.

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3

Couret, Marine. "Failure mechanisms implementation into SiGe HBT compact model operating close to safe operating area edges." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0265.

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Afin de répondre au marché florissant des applications térahertz, les filières BiCMOS atteignent désormais des fréquences de coupure supérieures à 0,5 THz. Ces performances dynamiques sont obtenues grâce aux améliorations technologiques apportées aux transistors bipolaires à hétérojonction (TBH) SiGe. Toutefois, cette montée en fréquence à entraîner un décalage du point de polarisation des transistors au plus proche, voir au-delà, de l’aire de sécurité de fonctionnement (SOA). En conséquence, de nombreux effets physiques « parasites » sont présents tel que l’ionisation par impact ou bien l’auto-échauffement pouvant potentiellement activer des mécanismes de défaillance et ainsi limiter la fiabilité à long terme du transistor. Dans le cadre de cette thèse, nous proposons une approche pour la description et la modélisation de la dégradation par porteurs chauds au sein des TBH SiGe fonctionnant aux frontières de la SOA. L’étude est basée sur une caractérisation approfondie en conditions statiques et dynamiques des transistors. Du fait de ses résultats de mesures, une modélisation de l’ionisation par impact et de l’auto-échauffement a été proposé permettant d’étendre, avec précision, le domaine de validité des modèles compact commerciaux (HiCuM). Au-vu du fonctionnement aux limites de la SOA, une campagne de vieillissement a été mise en place afin de mieux cerner l’origine physique de ce mécanisme de défaillance. De ce fait, il a été démontré que la dégradation par porteurs chauds entraîne la création de densités de pièges au niveau de l’interface Si/SiO2del’espaceur émetteur-base induisant un courant de recombinaison supplémentaire dans la base. Un modèle compact intégrant des lois de vieillissement (HiCuM-AL) a été développé prédisant l’évolution des paramètres électriques d’un transistor ou d’un circuit au travers d’un facteur de vieillissement accéléré. Afin de faciliter son utilisation dans des outils de conception assistée par ordinateur (CAO), les lois de vieillissement ont été adaptées en fonction de la géométrie et de l’architecture de l’espaceur émetteur-base. Le modèle a démontré sa robustesse et sa précision pour plusieurs technologies de TBH SiGe et, ce, pour différentes conditions de vieillissement. De plus, une étude de la fiabilité de plusieurs architectures de circuits intégrés a été réalisé menant à une localisation précise des régions les plus sensibles au mécanisme de dégradation par porteurs chauds. Le modèle HiCuM-AL ouvre ainsi la voie à des simulations optimisées pour la conception de circuits millimétriques en termes de performances, mais aussi de fiabilité à long terme<br>In an ever-growing terahertz market, BiCMOS technologies have reached cut-off frequencies beyond 0.5 THz. These dynamic performances are achieved thanks to the current technological improvements in SiGe heterojunction bipolar transistors (HBTs). However, these increased performances lead to a shift of the transistors bias point closer to, or even beyond, the conventional safe-operating-area (SOA). As a consequence, several "parasitic" physical effects are encountered such as impact-ionization or self-heating which can potentially activate failure mechanisms, hence limiting the long-term reliability of the electric device. In the framework of this thesis, we develop an approach for the description and the modeling of hot-carrier degradation occurring in SiGe HBTs when operating near the SOA edges. The study aims to provide an in-depth characterization of transistors operating under static and dynamic operating conditions. Based on these measurements results, a compact model for the impact-ionization and the self-heating has been proposed, ultimately allowing to extend the validity domain of a commercially available compact model (HiCuM). Considering the operation as close as possible to the SOA, an aging campaign was conducted to figure out the physical origin behind such failure mechanism. As a result, it has been demonstrated that hot-carrier degradation leads to the creation of trap densities at the Si/SiO2interface of the emitter-base spacer which induces an additional recombination current in the base. A compact model integrating aging laws (HiCuM-AL) was developed to predict the evolution of the transistor/circuit electrical parameters through an accelerated aging factor. For ease of use in computer-aided design (CAD) tools, the aging laws have been scaled according to the geometry and architecture of the emitter-base spacer. The model has demonstrated its robustness and its accuracy for different SiGe HBT technologies under various aging conditions. In addition, a study on the reliability of several integrated circuits has been performed leading to a precise location of the most sensitive regions to the hot-carrier degradation mechanism. Thus, the HiCuM-AL model paves the way to perform circuit simulations optimizing the mm-wave circuit design not only in term of sheer performances but also in term of long-term reliability
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4

Weststrate, Marnus. "LC-ladder and capacitive shunt-shunt feedback LNA modelling for wideband HBT receivers." Thesis, University of Pretoria, 2011. http://hdl.handle.net/2263/26615.

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Although the majority of wireless receiver subsystems have moved to digital signal processing over the last decade, the low noise amplifier (LNA) remains a crucial analogue subsystem in any design being the dominant subsystem in determining the noise figure (NF) and dynamic range of the receiver as a whole. In this research a novel LNA configuration, namely the LC-ladder and capacitive shunt-shunt feedback topology, was proposed for use in the implementation of very wideband LNAs. This was done after a thorough theoretical investigation of LNA configurations available in the body of knowledge from which it became apparent that for the most part narrowband LNA configurations are applied to wideband applications with suboptimal results, and also that the wideband configurations that exist have certain shortcomings. A mathematical model was derived to describe the new configuration and consists of equations for the input impedance, input return loss, gain and NF, as well as an approximation of the worst case IIP3. Compact design equations were also derived from this model and a design strategy was given which allows for electronic design automation of a LNA using this configuration. A process for simultaneously optimizing the circuit for minimum NF and maximum gain was deduced from this model and different means of improving the linearity of the LNA were given. This proposed design process was used successfully throughout this research. The accuracy of the mathematical model has been verified using simulations. Two versions of the LNA were also fabricated and the measured results compared well with these simulations. The good correlation found between the calculated, simulated and measured results prove the accuracy of the model, and some comments on how the accuracy of the model could be improved even further are provided as well. The simulated results of a LNA designed for the 1 GHz to 18 GHz band in the IBM 8HP process show a gain of 21.4 dB and a minimum NF of only 1.7 dB, increasing to 3.3 dB at the upper corner frequency while maintaining an input return loss below -10 dB. After steps were taken to improve the linearity, the IIP3 of the LNA is -14.5 dBm with only a small degradation in NF now 2.15 dB at the minimum. The power consumption of the respective LNAs are 12.75 mW and 23.25 mW and each LNA occupies a chip area of only 0.43 mm2. Measured results of the LNA fabricated in the IBM 7WL process had a gain of 10 dB compared to an expected simulated gain of 20 dB, however significant path loss was introduced by the IC package and PCB parasitics. The S11 tracked the simulated response very well and remained below -10 dB over the feasible frequency range. Reliable noise figure measurements could not be obtained. The measured P1dB compression point is -22 dBm. A 60 GHz LNA was also designed using this topology in a SiGe process with ƒT of 200 GHz. A simulated NF of 5.2 dB was achieved for a gain of 14.2 dB and an input return loss below -15 dB using three amplifier stages. The IIP3 of the LNA is -8.4 dBm and the power consumption 25.5 mW. Although these are acceptable results in the mm-wave range it was however found that the wideband nature of this configuration is redundant in the unlicensed 60 GHz band and results are often inconsistent with the design theory due to second order effects. The wideband results however prove that the LC-ladder and capacitive shunt-shunt feedback topology is a viable means for especially implementing LNAs that require a very wide operating frequency range and also very low NF over that range.<br>Thesis (PhD(Eng))--University of Pretoria, 2011.<br>Electrical, Electronic and Computer Engineering<br>unrestricted
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5

Bhattacharyya, Arkaprava. "Non quasi-static effects investigation for compact bipolar transistor modeling." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14294/document.

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Les transistors rapides actuels présentent un retard lorsqu’ils fonctionnent à très hautes fréquences ou en régime transitoire rapide. Cet effet est appelé effet non quasi-statique (NQS). Dans cette thèse, l’effet NQS est analysé de manière concise de façon à être directement implanté dans les modèles de composant pour les bibliothèques de circuit en utilisant le langage standard VerilogA. Les mécanismes physiques à la base de l’effet NQS sont évalués dans le domaine de fonctionnement petit signal et les résultats sont comparés aux travaux déjà publiés. S’agissant du modèle standard bipolaire HICUM, les effets NQS latéraux et verticaux sont examinés séparément à partir du même modèle, en régime de fonctionnement transitoire et fréquentiel grâce à un sous-circuit dédié au calcul de la phase du signal. A partir de ce sous-circuit, la modélisation compacte avec HICUM est comparée aux données issues de mesures et issues de simulation amont. Enfin, un nouveau sous-circuit calculant l’excès de phase est proposé pour prendre mieux en compte les effets non quasi-statiques dans les transistors bipolaires<br>Modern high speed (RF) transistors encounter certain delay while operated at high frequency or under fast transient condition. This effect is named as Non Quasi Static (NQS) effect. In the current work, NQS effect is analyzed in a concise manner so that it can be readily implemented in a compact model using the VerilogA description language. The basic physics behind this effect is investigated in small signal domain and the results are compared with the published work. In popular bipolar model HICUM lateral and vertical NQS are examined separately and uses the same model for both transient and AC operation which requires an additional minimum phase type sub circuit. Compact modeling with HICUM model is performed in both measurement and device simulated data. At last, an improved excess phase circuit is proposed to model the NQS effect
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6

Sahoo, Amit Kumar. "Electro-thermal Characterizations, Compact Modeling and TCAD based Device Simulations of advanced SiGe : C BiCMOS HBTs and of nanometric CMOS FET." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14557/document.

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Ce travail de thèse présente une évaluation approfondie des différentes techniques de mesure transitoire et dynamique pour l’évaluation du comportement électro-thermique des transistors bipolaires à hétérojonctions HBT SiGe:C de la technologie BiCMOS et des transistors Métal-Oxyde-Semiconducteur à effet de champ (MOSFET) de la technologie CMOS 45nm. En particulier, je propose une nouvelle approche pour caractériser avec précision le régime transitoire d'auto-échauffement, basée sur des mesures impulsionelles. La méthodologie a été vérifiée par des mesures statiques à différentes températures ambiantes, des mesures de paramètres S à basses fréquences et des simulations thermiques transitoires. Des simulations thermiques par éléments finis (TCAD) en trois dimensions ont été réalisées sur les transistors HBTs de la technologie submicroniques SiGe: C BiCMOS. Cette technologie est caractérisée par une fréquence de transition fT de 230 GHz et une fréquence maximum d’oscillation fMAX de 290 GHz. Par ailleurs, cette étude a été réalisée sur les différentes géométries de transistor. Une évaluation complète des mécanismes d'auto-échauffement dans les domaines temporels et fréquentiels a été réalisée. Une expression généralisée de l'impédance thermique dans le domaine fréquentiel a été formulée et a été utilisé pour extraire cette impédance en deçà de la fréquence de coupure thermique. Les paramètres thermiques ont été extraits par des simulations compactes grâce au modèle compact de transistors auquel un modèle électro-thermique a été ajouté via le nœud de température. Les travaux théoriques développés à ce jour pour la modélisation d'impédance thermique ont été vérifiés avec nos résultats expérimentaux. Il a été montré que, le réseau thermique classique utilisant un pôle unique n'est pas suffisant pour modéliser avec précision le comportement thermique transitoire et donc qu’un réseau plus complexe doit être utilisé. Ainsi, nous validons expérimentalement pour la première fois, le modèle distribué électrothermique de l'impédance thermique utilisant un réseau nodal récursif. Le réseau récursif a été vérifié par des simulations TCAD, ainsi que par des mesures et celles ci se sont révélées en excellent accord. Par conséquent, un modèle électro-thermique multi-géométries basé sur le réseau récursif a été développé. Le modèle a été vérifié par des simulations numériques ainsi que par des mesures de paramètre S à basse fréquence et finalement la conformité est excellente quelque soit la géométrie des dispositifs<br>An extensive evaluation of different techniques for transient and dynamic electro-thermal behavior of microwave SiGe:C BiCMOS hetero-junction bipolar transistors (HBT) and nano-scale metal-oxide-semiconductor field-effect transistors (MOSFETs) have been presented. In particular, new and simple approach to accurately characterize the transient self-heating effect, based on pulse measurements, is demonstrated. The methodology is verified by static measurements at different ambient temperatures, s-parameter measurements at low frequency region and transient thermal simulations. Three dimensional thermal TCAD simulations are performed on different geometries of the submicron SiGe:C BiCMOS HBTs with fT and fmax of 230 GHz and 290 GHz, respectively. A comprehensive evaluation of device self-heating in time and frequency domain has been investigated. A generalized expression for the frequency-domain thermal impedance has been formulated and that is used to extract device thermal impedance below thermal cut-off frequency. The thermal parameters are extracted through transistor compact model simulations connecting electro-thermal network at temperature node. Theoretical works for thermal impedance modeling using different networks, developed until date, have been verified with our experimental results. We report for the first time the experimental verification of the distributed electrothermal model for thermal impedance using a nodal and recursive network. It has been shown that, the conventional single pole thermal network is not sufficient to accurately model the transient thermal spreading behavior and therefore a recursive network needs to be used. Recursive network is verified with device simulations as well as measurements and found to be in excellent agreement. Therefore, finally a scalable electro-thermal model using this recursive network is developed. The scalability has been verified through numerical simulations as well as by low frequency measurements and excellent conformity has been found in for various device geometries
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7

Liang, Qingqing. "Systematic Analysis and Optimization of Broadband Noise and Linearity in SiGe HBTs." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6980.

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Noise and linearity are the two key concerns in RF transceiver systems. However, the impact of circuit topology and device technology on systems noise and linearity behaviors is poorly understood because of the complexity and diversity involved. There are two general questions that are addressed by the RF device and circuit designers: for a given device technology, how best to optimize the circuit topology; and for a given circuit topology, how best to optimize the device technology to improve the noise and linearity performance. In this dissertation, a systematic noise and linearity calculation method is proposed. This approach offers simple and analytical solutions to optimize the noise and linearity characteristics of integrated circuits. Supported by this approach, the physics of state-of-the-art SiGe HBT technology devices can be decoupled and studied. The corresponding impact on noise and linearity is investigated. New optimization methodologies for noise and linearity at both the device and circuit level are presented. In addition, this thesis demonstrates a technique that accurately extracts ac and noise parameters of devices/circuits in the millimeter-wave range. The extraction technique supports and verifies the device/circuit noise analysis from a measurement standpoint.
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8

Cheng, Peng. "A Current Sweep Method for Assessing the Mixed-Mode Damage Spectrum of SIGe HBTS." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19756.

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In this work a new current-sweep stress methodology for quantitatively assessing the mixed-mode reliability (simultaneous application of high current and high voltage) of advanced SiGe HBTs is presented. This stress methodology allows one to quickly obtain the complete damage spectrum of a given device from a particular technology platform, enabling better understanding of the complex voltage, current, and temperature interdependence associated with electrical stress and burn-in of advanced transistors. We consistently observed three distinct regions of mixed-mode damage in SiGe HBTs, and find that hot carrier induced damage can be introduced into SiGe HBTs under surprisingly modest mixed-mode stress conditions. For more aggressively scaled silicon-germanium technology generations, a larger percentage of hot carriers generated in the collector-base junction are able to travel to and hence damage the EB spacer, leading to enhanced forward-mode base current leakage under stress. A new self-heating induced mixed-mode annealing effect was observed for the first time under fairly high voltage and current stress conditions, and a new damage mechanism was observed under very high voltage and current conditions. Finally, as an example of the utility of our stress methodology, we quantified the composite mixed-mode damage spectrum of a commercial third-generation (200 GHz) generation SiGe HBT. It is found that if devices are stressed with either voltage or current alone during burn-in, they can easily withstand extreme over-stress conditions. Unfortunately, devices were easily damaged when stressed with a combination of stress voltage and current, and this has significant implications for the device and circuit lifetime prediction under realistic mixed-signal operating conditions.
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9

Banerjee, Bhaskar. "Development of Broadband Noise Models and Radio Frequency Integrated Circuits using Silicon Germanium HBTs." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/13984.

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A novel transit time based analytical broadband noise model is developed and implemented for high frequency bipolar transistors. This model is applied to a complementary (npn + pnp) silicon germanium (SiGe) heterojunction bipolar transistors (HBT). A complete set of analytical equations are derived using this transit time noise model, to express the four fundamental noise parameters in terms of device parameters. A comprehensive analysis on the ac, dc and broadband noise performance of a 200 GHz SiGe HBT technology, under cryogenic temperatures, is presented. The transit time based noise model is used to analyze the RF noise behavior of the SiGe HBT down to 85 K. Significant performance gain is demonstrated in cryogenic temperatures indicating the suitability of SiGe HBT for extreme environment electronics. A sub-circuit based substrate parasitic modeling methodology, in silicon based processes, is presented. A test case low noise amplifier, operating in the 5 GHz band, is designed in a SiGe HBT process and is used to demonstrate the validity of the design methodology. A dual-band, dual-mode transceiver front end for IEEE802.11a/b/g WLAN applications, is designed in a 0.8 and #956;m SiGe HBT process. The transceiver uses a new architecture which uses an on-chip frequency doubler and a single off-chip frequency synthesizer for both the 2.4 and 5 GHz bands. The performance of the transceiver meets the specification of the IEEE802.11a/b/g standards. The work described in the dissertation significantly advances the state-of-the-art in bipolar broadband noise modeling and RF, microwave circuit design using silicon based processes. The contributions and implications of this work for future research are discussed.
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Zhu, Chendong. "The mixed-mode reliability stress of Silicon-Germanium heterojunction bipolar transistors." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14647.

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The objective of the dissertation is to combine the recent Mixed-Mode reliability stress studies into a single text. The thesis starts with a review of silicon-germanium heterojunction bipolar transistor fundamentals, development trends, and the conventional reliability stress paths used in industry, after which the new stress path, Mixed-Mode stress, is introduced. Chapter 2 is devoted to an in-depth discussion of damage mechanisms that includes the impact ionization effct and the selfheating effect. Chapter 3 goes onto the impact ionization effect using two-dimensional calibrated MEDICI simulations. Chapter 4 assesses the reliability of SiGe HBTs in extreme temperature environments by way of comprehensive experiments and MEDICI simulations. A comparison of the device lifetimes for reverse-EB stress and mixed-mode stress indicates different damage mechanisms govern these phenomena. The thesis concludes with a summary of the project and suggestions for future research in chapter 5.
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11

D'Esposito, Rosario. "Electro-thermal characterization, TCAD simulations and compact modeling of advanced SiGe HBTs at device and circuit level." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0147/document.

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Ce travail de thèse présente une étude concernant la caractérisation des effets électrothermiques dans les transistors bipolaires à hétérojonction (HBT) en SiGe. Lors de ces travaux, deux procédés technologiques BiCMOS à l’état de l’art ont été analysés: le B11HFC de Infineon Technologies (130nm) et le B55 de STMicroelectronics (55nm).Des structures de test dédiées ont étés conçues, pour évaluer l’impact électrothermique du back end of line (BEOL) de composants ayant une architecture à un ou plusieurs doigts d’émetteur. Une caractérisation complète a été effectuée en régime continu et en mode alternatif en petit et en grand signal. De plus, une extraction des paramètres thermiques statiques et dynamiques a été réalisée et présentée pour les structures de test proposées. Il est démontré que les figures de mérite DC et RF s’améliorent sensiblement en positionnant des couches de métal sur le transistor, dessinées de manière innovante et ayant pour fonction de guider le flux thermique vers l’extérieur. L’impact thermique du BEOL a été modélisé et vérifié expérimentalement dans le domaine temporel et fréquentiel et aussi grâce à des simulations 3D par éléments finis. Il est à noter que l’effet du profil de dopage sur la conductivité thermique est analysé et pris en compte.Des topologies de transistor innovantes ont étés conçues, permettant une amélioration des spécifications de l’aire de sécurité de fonctionnement, grâce à un dessin innovant de la surface d’émetteur et du deep trench (DTI).Un modèle compact est proposé pour simuler les effets de couplage thermique en dynamique entre les émetteurs des HBT multi-doigts; ensuite le modèle est validé avec de mesures dédiées et des simulations TCAD.Des circuits de test ont étés conçus et mesurés, pour vérifier la précision des modèles compacts utilisés dans les simulateurs de circuits; de plus, l’impact du couplage thermique entre les transistors sur les performances des circuits a été évalué et modélisé. Finalement, l’impact du dissipateur thermique positionné sur le transistor a été étudié au niveau circuit, montrant un réel intérêt de cette approche<br>This work is focused on the characterization of electro-thermal effects in advanced SiGe hetero-junction bipolar transistors (HBTs); two state of the art BiCMOS processes have been analyzed: the B11HFC from Infineon Technologies (130nm) and the B55 from STMicroelectronics (55nm).Special test structures have been designed, in order to evaluate the overall electro-thermal impact of the back end of line (BEOL) in single finger and multi-finger components. A complete DC and RF electrical characterization at small and large signal, as well as the extraction of the device static and dynamic thermal parameters are performed on the proposed test structures, showing a sensible improvement of the DC and RF figures of merit when metal dummies are added upon the transistor. The thermal impact of the BEOL has been modeled and experimentally verified in the time and frequency domain and by means of 3D TCAD simulations, in which the effect of the doping profile on the thermal conductivity is analyzed and taken into account.Innovative multi-finger transistor topologies are designed, which allow an improvement of the SOA specifications, thanks to a careful design of the drawn emitter area and of the deep trench isolation (DTI) enclosed area.A compact thermal model is proposed for taking into account the mutual thermal coupling between the emitter stripes of multi-finger HBTs in dynamic operation and is validated upon dedicated pulsed measurements and TCAD simulations.Specially designed circuit blocks have been realized and measured, in order to verify the accuracy of device compact models in electrical circuit simulators; moreover the impact on the circuit performances of mutual thermal coupling among neighboring transistors and the presence of BEOL metal dummies is evaluated and modeled
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Indrák, Martin. "Komplexní zhodnocení finanční pozice podniku Coca Cola HBC Česká republika." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-10561.

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The Purpose of this thesis is to briefly describe the company but also the whole branch of soft drinks production. The Dissertation investigate financial structure and analyzes the company through particular instruments of financial analysis such as absolute and ratio indexes, Du Pont decomposition, Altman index, Model IN and Economic value added. Also comparison with the biggest and most dangerous competitors on the market is the other essential part. Output of this thesis presents the evaluation of the financial health and condition of the company, its market position and last but not least some little recommendations, if needed.
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Rosenbaum, Tommy. "Performance prediction of a future silicon-germanium heterojunction bipolar transistor technology using a heterogeneous set of simulation tools and approaches." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0550/document.

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Les procédés bipolaires semi-conducteurs complémentaires à oxyde de métal (BiCMOS) peuvent être considérés comme étant la solution la plus généralepour les produits RF car ils combinent la fabrication sophistiquée du CMOSavec la vitesse et les capacités de conduction des transistors bipolaires silicium germanium(SiGe) à hétérojonction (HBT). Les HBTs, réciproquement, sontles principaux concurrents pour combler partiellement l'écart de térahertzqui décrit la plage dans laquelle les fréquences générées par les transistors etles lasers ne se chevauchent pas (environ 0.3 THz à 30 THz). A_n d'évaluerles capacités de ces dispositifs futurs, une méthodologie de prévision fiable estsouhaitable. L'utilisation d'un ensemble hétérogène d'outils et de méthodes desimulations permet d'atteindre successivement cet objectif et est avantageusepour la résolution des problèmes. Plusieurs domaines scientifiques sont combinés, tel que la technologie de conception assistée par ordinateur (TCAO),la modélisation compacte et l'extraction des paramètres.Afin de créer une base pour l'environnement de simulation et d'améliorerla confirmabilité pour les lecteurs, les modèles de matériaux utilisés pour lesapproches hydrodynamiques et de diffusion par conduction sont introduits dèsle début de la thèse. Les modèles physiques sont principalement fondés surdes données de la littérature basées sur simulations Monte Carlo (MC) ou dessimulations déterministes de l'équation de transport de Boltzmann (BTE).Néanmoins, le module de TCAO doit être aussi étalonné sur les données demesure pour une prévision fiable des performances des HBTs. L'approchecorrespondante d'étalonnage est basée sur les mesures d'une technologie depointe de HBT SiGe pour laquelle un ensemble de paramètres spécifiques àla technologie du modèle compact HICUM/L2 est extrait pour les versionsdu transistor à haute vitesse, moyenne et haute tension. En s'aidant de cesrésultats, les caractéristiques du transistor unidimensionnel qui sont généréesservent de référence pour le profil de dopage et l'étalonnage du modèle. Enélaborant des comparaisons entre les données de références basées sur les mesureset les simulations, la thèse fait progresser l'état actuel des prévisionsbasées sur la technologie CAO et démontre la faisabilité de l'approche.Enfin, une technologie future de 28nm performante est prédite en appliquantla méthodologie hétérogène. Sur la base des résultats de TCAO, leslimites de la technologie sont soulignées<br>Bipolar complementary metal-oxide-semiconductor (BiCMOS) processescan be considered as the most general solution for RF products, as theycombine the mature manufacturing tools of CMOS with the speed and drivecapabilities of silicon-germanium (SiGe) heterojunction bipolar transistors(HBTs). HBTs in turn are major contenders for partially filling the terahertzgap, which describes the range in which the frequencies generated bytransistors and lasers do not overlap (approximately 0.3THz to 30 THz). Toevaluate the capabilities of such future devices, a reliable prediction methodologyis desirable. Using a heterogeneous set of simulation tools and approachesallows to achieve this goal successively and is beneficial for troubleshooting.Various scientific fields are combined, such as technology computer-aided design(TCAD), compact modeling and parameter extraction.To create a foundation for the simulation environment and to ensure reproducibility,the used material models of the hydrodynamic and drift-diffusionapproaches are introduced in the beginning of this thesis. The physical modelsare mainly based on literature data of Monte Carlo (MC) or deterministicsimulations of the Boltzmann transport equation (BTE). However, the TCADdeck must be calibrated on measurement data too for a reliable performanceprediction of HBTs. The corresponding calibration approach is based onmeasurements of an advanced SiGe HBT technology for which a technology specific parameter set of the HICUM/L2 compact model is extracted for thehigh-speed, medium-voltage and high-voltage transistor versions. With thehelp of the results, one-dimensional transistor characteristics are generatedthat serve as reference for the doping profile and model calibration. By performingelaborate comparisons between measurement-based reference dataand simulations, the thesis advances the state-of-the-art of TCAD-based predictionsand proofs the feasibility of the approach.Finally, the performance of a future technology in 28nm is predicted byapplying the heterogeneous methodology. On the basis of the TCAD results,bottlenecks of the technology are identified<br>Bipolare komplementäre Metall-Oxid-Halbleiter (BiCMOS) Prozesse bietenhervorragende Rahmenbedingungen um Hochfrequenzanwendungen zurealisieren, da sie die fortschrittliche Fertigungstechnik von CMOS mit derGeschwindigkeit und Treiberleistung von Silizium-Germanium (SiGe) Heterostruktur-Bipolartransistoren (HBTs) verknüpfen. Zudem sind HBTs bedeutendeWettbewerber für die teilweise Überbrückung der Terahertz-Lücke, derFrequenzbereich zwischen Transistoren (&lt; 0.3 THz) und Lasern (&gt; 30 THz).Um die Leistungsfähigkeit solcher zukünftigen Bauelemente zu bewerten, isteine zuverlässige Methodologie zur Vorhersage notwendig. Die Verwendungeiner heterogenen Zusammenstellung von Simulationstools und Lösungsansätzenerlaubt es dieses Ziel schrittweise zu erreichen und erleichtert die Fehler-_ndung. Verschiedene wissenschaftliche Bereiche werden kombiniert, wie zumBeispiel der rechnergestützte Entwurf für Technologie (TCAD), die Kompaktmodellierungund Parameterextraktion.Die verwendeten Modelle des hydrodynamischen Simulationsansatzes werdenzu Beginn der Arbeit vorgestellt, um die Simulationseinstellung zu erläuternund somit die Nachvollziehbarkeit für den Leser zu verbessern. Die physikalischenModelle basieren hauptsächlich auf Literaturdaten von Monte Carlo(MC) oder deterministischen Simulationen der Boltzmann-Transportgleichung(BTE). Für eine zuverlässige Vorhersage der Eigenschaften von HBTs muss dieTCAD Kon_guration jedoch zusätzlich auf der Grundlage von Messdaten kalibriertwerden. Der zugehörige Ansatz zur Kalibrierung beruht auf Messungeneiner fortschrittlichen SiGe HBT Technologie, für welche ein technologiespezifischer HICUM/L2 Parametersatz für die high-speed, medium-voltage undhigh-voltage Transistoren extrahiert wird. Mit diesen Ergebnissen werden eindimensionaleTransistorcharakteristiken generiert, die als Referenzdaten fürdie Kalibrierung von Dotierungspro_len und physikalischer Modelle genutztwerden. Der ausführliche Vergleich dieser Referenz- und Messdaten mit Simulationengeht über den Stand der Technik TCAD-basierender Vorhersagenhinaus und weist die Machbarkeit des heterogenen Ansatzes nach.Schlieÿlich wird die Leistungsfähigkeit einer zukünftigen Technologie in28nm unter Anwendung der heterogenen Methodik vorhergesagt. Anhand derTCAD Ergebnisse wird auf Engpässe der Technologie hingewiesen
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14

García, Fernández Víctor Gerardo. "Constitutive relations to model the hot flow of commercial purity copper." Doctoral thesis, Universitat Politècnica de Catalunya, 2004. http://hdl.handle.net/10803/6043.

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Se ha llevado a cabo un estudio con el fin de observar diferencias en el comportamiento de fluencia en caliente de los cobres refinados al fuego con una pureza de 99.9%, dicho estudio ha permitido proponer modelos para predecir la curva esfuerzo-deformación y para predecir el tamaño de grano recristalizado dinámicamente. Los cobres refinados al fuego con una pureza de 99.9% se caracterizan por tener una composición residual de varios otros elementos, en algunos casos hasta 1000ppm. En los cobres con por lo menos 99.9% de pureza que tengan pocos elementos residuales, las diferencias observadas durante la fluencia en caliente se atribuyen a las interacciones entre átomos disueltos y dislocaciones, específicamente las interacciones con oxígeno intersticial. En el cobre electrolítico, el cual contiene principalmente altos contenidos de oxigeno, las diferencias de fluencia se atribuyen a cantidades cada vez mayores de partículas de Cu2O. Este trabajo más bien demuestra que las diferencias de esfuerzo encontradas en cobres refinados al fuego con una pureza de 99.9% son debidas a la cantidad de oxígeno residual, el cual forma finos precipitados a temperaturas intermedias que refuerzan la matriz metálica. A pesar del bajo contenido en oxígeno en los cobres estudiados (26-62ppm) se han caracterizado precipitados de Cu2O y se han utilizado teorías del endurecimiento por precipitación que han indicado que los precipitados de Cu2O eran los responsables del incremento en resistencia. Las interacciones entre átomos de oxígeno y dislocaciones son poco probables que causen un retro esfuerzo adicional a temperaturas superiores a los 600º C, en donde se ha llevado a cabo este trabajo. Se han comprimido tres cobres con 26, 46 y 62ppm de oxígeno a unas velocidades de deformación de 0.3s-1, 0.1s-1, 0.03s-1, 0.01s-1, 0.003s-1 y 0.001s-1 y a unas temperaturas desde 600º C hasta 950º C en intervalos de 50º. En este trabajo se presenta evidencia de cómo bajos contenidos de oxígeno en cobres 99.9% puros pueden afectar el comportamiento esfuerzo-deformación y el tamaño de grano recristalizado dinámicamente.<br/><br/>Además de haber encontrado el elemento y el mecanismo responsable del retro esfuerzo adicional también se presenta un algoritmo matemático para estudiar y predecir las oscilaciones de esfuerzo durante la recristalización dinámica de pico múltiple. Intentos anteriores utilizando Modelos Computarizados de Monte Carlo, Modelos de Autómatas Celulares o Modelos Matemáticos para la Recristalización Dinámica (DRX) no predicen las oscilaciones de esfuerzo de materiales reales y su tiempo de computo los hace inviables para procesos de simulación industrial. El nuevo Modelo de Avrami con Coseno Amortiguado para la DRX es capaz de predecir la transición de DRX de pico simple a DRX de pico múltiple. Además el nuevo modelo define el esfuerzo de estado estable sin tener que escoger un valor de una curva experimental que posiblemente no haya alcanzado un estado estable. Otra contribución del nuevo modelo es que demuestra que las oscilaciones son completamente predecibles en términos de la velocidad de deformación y la temperatura, una característica que antes se había dicho ser improbable. El nuevo modelo para la DRX junto con un modelo modificado de Voce-Kocks para la restauración dinámica han sido exitosamente implementados para predecir la fluencia en caliente.<br/><br/>Adicionalmente a las anteriores contribuciones este trabajo también da a conocer la relación que tiene el tamaño de grano recristalizado con la temperatura y la velocidad de deformación. Se asume que los cobres 99.9% puros, como los estudiados, tenderán a un tamaño de grano de estado estable el cual cuando esté a temperatura ambiente determinará las propiedades mecánicas del producto forjado.
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15

Venkataraman, Sunitha. "Systematic Analysis of the Small-Signal and Broadband Noise Performance of Highly Scaled Silicon-Based Field-Effect Transistors." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16232.

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The objective of this work is to provide a comprehensive analysis of the small-signal and broadband noise performance of highly scaled silicon-based field-effect transistors (FETs), and develop high-frequency noise models for robust radio frequency (RF) circuit design. An analytical RF noise model is developed and implemented for scaled Si-CMOS devices, using a direct extraction procedure based on the linear two-port noise theory. This research also focuses on investigating the applicability of modern CMOS technologies for extreme environment electronics. A thorough analysis of the DC, small-signal AC, and broadband noise performance of 0.18 um and 130 nm Si-CMOS devices operating at cryogenic temperatures is presented. The room temperature RF noise model is extended to model the high-frequency noise performance of scaled MOSFETs at temperatures down to 77 K and 10 K. Significant performance enhancement at cryogenic temperatures is demonstrated, indicating the suitability of scaled CMOS technologies for low temperature electronics. The hot-carrier reliability of MOSFETs at cryogenic temperatures is investigated and the worst-case gate voltage stress condition is determined. The degradation due to hot-carrier-induced interface-state creation is identified as the dominant degradation mechanism at room temperature down to 77 K. The effect of high-energy proton radiation on the DC, AC, and RF noise performance of 130 nm CMOS devices is studied. The performance degradation is investigated up to an equivalent total dose of 1 Mrad, which represents the worst case condition for many earth-orbiting and planetary missions. The geometric scaling of MOSFETs has been augmented by the introduction of novel FET designs, such as the Si/SiGe MODFETs. A comprehensive characterization and modeling of the small-signal and high-frequency noise performance of highly scaled Si/SiGe n-MODFETs is presented. The effect of gate shot noise is incorporated in the broadband noise model. SiGe MODFETs offer the potential for high-speed and low-voltage operation at high frequencies and hence are attractive devices for future RF and mixed-signal applications. This work advances the state-of-the-art in the understanding and analysis of the RF performance of highly scaled Si-CMOS devices as well as emerging technologies, such as Si/SiGe MODFETs. The key contribution of this dissertation is to provide a robust framework for the systematic characterization, analysis and modeling of the small-signal and RF noise performance of scaled Si-MOSFETs and Si/SiGe MODFETs both for mainstream and extreme-environment applications.
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16

Srirattana, Nuttapong. "High-Efficiency Linear RF Power Amplifiers Development." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6899.

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Next generation mobile communication systems require the use of linear RF power amplifier for higher data transmission rates. However, linear RF power amplifiers are inherently inefficient and usually require additional circuits or further system adjustments for better efficiency. This dissertation focuses on the development of new efficiency enhancement schemes for linear RF power amplifiers. The multistage Doherty amplifier technique is proposed to improve the performance of linear RF power amplifiers operated in a low power level. This technique advances the original Doherty amplifier scheme by improving the efficiency at much lower power level. The proposed technique is supported by a new approach in device periphery calculation to reduce AM/AM distortion and a further improvement of linearity by the bias adaptation concept. The device periphery adjustment technique for efficiency enhancement of power amplifier integrated circuits is also proposed in this work. The concept is clearly explained together with its implementation on CMOS and SiGe RF power amplifier designs. Furthermore, linearity improvement technique using the cancellation of nonlinear terms is proposed for the CMOS power amplifier in combination with the efficiency enhancement technique. In addition to the efficiency enhancement of power amplifiers, a scalable large-signal MOSFET model using the modified BSIM3v3 approach is proposed. A new scalable substrate network model is developed to enhance the accuracy of the BSIM3v3 model in RF and microwave applications. The proposed model simplifies the modeling of substrate coupling effects in MOS transistor and provides great accuracy in both small-signal and large-signal performances.
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17

Wu, Chun-Wei, and 吳俊緯. "X-parameter Model for SiGe HBT Power Amplifier Design Operating in Avalanche Breakdown Region." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/u5g95e.

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碩士<br>國立中山大學<br>電機工程學系研究所<br>106<br>The prediction method of power contours from X-parameter model at different load impedance, this method is faster and wider than the conventional Load-pull method to predict SiGe HBT’s power contour , get optimization load impedance. In SiGe HBT , the linearity of output power operating in avalanche breakdown region is more higher than operating in working area. However, output power, gain, and PAE are slightly degraded. This investigation designs SiGe HBT power amplifier operating in avalanche breakdown region, exchanges dissipation power for high linearity, meases the characterists of the power amplifier.
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18

Chen, Ho-Yin, and 陳和穎. "The Device Model of SiGe HBTs Operated under High Collector Voltage Bias." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/52269697172808380296.

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碩士<br>國立清華大學<br>電子工程研究所<br>92<br>The 0.18μm SiGe HBTs operated under high collector bias are analyzed and modeled in this thesis. A new mechanism is found that SiGe HBTs operate at high collector voltage will have two current jumps. These two sudden current jumps occur is due to tunneling effect of electrons in two quantum levels which are formed by conduction band discontinuity at collector-base junction. By multiplying those tunneling electrons with avalanche multiplication factor in the depletion region, large amount of electron-hole pairs will flow out of collector and base terminals. Two stages of current jumps in IC and IB take place correspond to tunnel effect of two quantum levels. Two current jumps at high collector voltage split IC and IB into four regions, respectively. A device model is built by adding on a general HBT equivalent circuit with four switch controlled paths between both collector-emitter and base-emitter junction. Therefore, the model in this thesis can fit the measured results with widely operating range quite accurately. Some useful applications can be simulated by this developed model, such as small signal characteristics, ac characteristics, and circuit design. There may still have many valuable applications for this new mechanism.
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19

Alves, João Carlos das Neves. "Modelação de sistemas de AQS com painéis solares térmicos e apoio elétrico." Master's thesis, 2016. http://hdl.handle.net/10316/81489.

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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia<br>O sistema solar térmico para aquecimento de água é utilizado principalmente em ambiente doméstico para as Águas Quentes Sanitárias, sendo nos dias de hoje um serviço indispensável para o bem-estar de todos nós. De modo a garantir a estabilidade dos sistemas de energia elétrica, tendo em conta a descentralização da geração elétrica e a produção a nível local, a gestão da procura tem ganho cada vez mais importância. A gestão da procura permite desviar e diminuir consumos de energia eléctrica, pelo que pode ser usada para evitar picos da procura, no entanto, para o consumidor final, a gestão da procura torna-se mais interessante se utilizada com a finalidade de desviar consumos para reduzir a fatura da eletricidade. É neste âmbito que no presente trabalho serão utilizados softwares de simulação de gestão da procura, de modo a tornar os sistemas de aquecimento de águas sanitárias mais eficientes e mais apelativos em termos económicos.O presente trabalho foi desenvolvido no âmbito da Dissertação de Mestrado Integrado em Engenharia Eletrotécnica e de Computadores, lecionada no Departamento de Engenharia Eletrotécnica e de Computadores da Faculdade de Ciências e Tecnologia da Universidade de Coimbra, no ano letivo 2015/2016, tendo como objetivo a criação e modelação de sistemas de aquecimento de água quente com painéis térmicos e apoio elétrico.Neste trabalho é apresentada a simulação e comparação de vários modelos de sistema solar térmico, entre os quais, o sistema termossifão, o sistema de circulação forçada com aquecimento direto e indireto.É também apresentado um algoritmo desenvolvido em MATLAB, validado através do TRNSYS, que dada a previsão da temperatura, da radiação solar e do consumo diário é capaz de conseguir reproduzir o funcionamento de um sistema de águas quentes sanitárias com painéis solares e apoio elétrico de circulação forçada e aquecimento indireto. Com esta ferramenta é possível simular e analisar cenários alternativos de funcionamento dos sistemas de aquecimento solar de água com apoio elétrico. As ações submetidas no funcionamento normal do algoritmo são a variação da temperatura máxima do depósito e a introdução de interrupções definidas pelo utilizador.Com a introdução das chamadas redes inteligentes (Smart grids), surgiu a oportunidade de entregar energia de uma forma controlada e inteligente desde o ponto de geração até ao consumidor, devido à evolução das tecnologias de informação e comunicação (TIC). Para observar as ações de gestão do lado da procura que podem ser avaliadas, foi desenvolvida uma ferramenta de simulação que permite alterar o funcionamento normal do algoritmo que tinha sido criado para simular o sistema de aquecimento de água quente com painéis térmicos e apoio elétrico em Matlab.<br>The solar thermal energy system for water heating is used mainly for domestic consumption for the Sanitary Hot Waters, being nowadays an essential good for the wellbeing of everyone.With the purpose of granting Electric Energy Systems stability, taking into account the decentralized electricity generation and local production, demand side management has gained increasing importance.The demand management divert and reduce electrical energy consumption, therefore can be used to prevent peak demand, however, for the end consumer, demand management becomes more interesting if used for the purpose of diverting consumption to reduce the invoice of electricity. It is in this context that the present work will make use of simulation software for demand management, in order to make the sanitary water heating systems more efficient and more attractive in economic terms. This work was developed within the framework of the Masters dissertation of the Master’s degree in Electrical and Computer Engineering, taught in the Department of Electrical and Computer Engineering of the Faculty of Sciences and Technology of the University of Coimbra, in the academic year of 2015/2016 with the purpose of modeling the sanitary hot water systems with thermal panels and electrical support.In this work, a simulation and comparison of various solar thermal energy systems is presented, among which are: the thermosiphon system and the forced-circulation system with direct and indirect heating.It is also presented a MATLAB developed algorithm is validated through TRNSYS, which when given the temperature prediction of the solar radiation and daily consumption is capable of reproducing a system of sanitary hot water systems with solar panels and electrical support and forced-circulation and indirect heating. With this tool it is possible to simulate and analyze alternative scenarios of operation of solar water heating systems with electrical support. The actions subjected to the normal operation of the algorithm are the maximum variation in temperature of the tank and the insertion of interruptions defined by the user.With the introduction of so-called intelligent networks (smart grids), the opportunity arose to deliver energy in a controlled and intelligent manner from the point of generation to the consumer, due to the evolution of information and communication technologies (ICT). To observe the demand side management actions that can be evaluated, a simulation tool that allows the change of normal operation of the algorithm that had been created to simulate the hot water heating system with thermal panels and electrical support in Matlab was developed.
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