|
| ||
|
|
||
Bipolar Transistors (bipolar + transistor)
Kinds of Bipolar Transistors Selected AbstractsThermal analysis of multi-finger GaInP collector-up heterojunction bipolar transistors with miniature heat-dissipation packaging structuresINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2010Pei-Hsuan Lee Abstract We build up a finite element modeling (FEM) approach to analyze the thermal performance of collector-up (C-up) heterojunction bipolar transistor (HBTs) with a heat-dissipation via configuration. Highly compact heat-dissipation packaging structures of GaInP/GaAs C-up HBTs have been designed and evaluated systematically. In this work, we devise the 2-D and 3-D models to simulate the actual devices and to investigate the temperature distribution behavior. Results from 2-D model indicate that the large heat-dissipation via configuration can be further reduced by 29% to meet the requirement of HBT-based small high-power amplifiers (HPAs) for the cellular phones. Furthermore, the demonstrated results show that the maximum temperature within the collector calculated from 3-D model is lower than that from 2-D model. In the 3-D analysis, it is revealed that the configuration can be reduced by 32%. Therefore, thinning the heat-dissipation via constructed underneath the GaInP/GaAs C-up HBT should be helpful for miniaturization of HBT-based HPAs in future mobile communication systems. Copyright © 2009 John Wiley & Sons, Ltd. [source] Mixed-mode analysis of the sensitivity of a radiofrequency oscillator disturbed by parasitic signalsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2009Christian Gontrand Abstract The first step of this work is to study the susceptibility of a radiofrequency oscillator to deterministic disturbance sources. A Colpitts oscillator, working around a 4,GHz frequency, contains a heterojunction bipolar transistor with a silicon,germanium base as an active device. A mixed-mode analysis is involved, applying a microscopic drift diffusion model to the device, whereas the rest of the circuit used is governed by Kirchhoff's laws. We assume that this tool is very relevant to grasp the influence of intrinsic or extrinsic noisy sources of the oscillator. Our first simulation raw results motivate us to discuss, and perhaps extend, via some analytical models, the so-called impulse sensitivity function model. In this paper, we try to develop quantitative predictions about the phase noise of such oscillators, and to give some new tracks on this field. Copyright © 2008 John Wiley & Sons, Ltd. [source] Parameters estimation of the d.c. electrothermal model of the bipolar transistorINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 2 2002Janusz Zar Abstract This paper concerns the problems of the parameter values estimation of d.c. electrothermal model of the BJT formulated for circuit analysis with SPICE. In this case, PARTS software available in SPICE cannot be used. In the paper, a new estimation algorithm for d.c. electrothermal model of the BJT is proposed. The form of the electrothermal BJT model is also presented. The estimation algorithm implemented into the computer-controlled measurement set allows one to derive the values of the parameters automatically after the measurements of the selected isothermal characteristics and proper calculations. Copyright © 2002 John Wiley & Sons, Ltd. [source] Direct growth of GaN on off-oriented SiC (0001) by molecular-beam epitaxy for GaN/SiC heterojunction bipolar transistorPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005Y. Nakano Abstract Direct growth of GaN on misoriented 4H- and 6H-SiC (0001) Si-face substrates and electrical characteristics of n-GaN/p-SiC heterojunction mesa diodes are presented. GaN was grown by molecular-beam epitaxy (MBE) using elemental Ga and rf plasma-excited active nitrogen. SiC substrates misoriented 8° toward the [11-20] direction were used in this study. The surfaces of MBE-grown GaN layers have wavy features with peak-to-valley height of 30 nm. These features originated from the substrate misorientation. It was found that step bunching and large faceting along [01-10] and [10-10] directions occurred during the growth of GaN. Lowering the growth temperature suppresses large faceting, and results in reduction of the peak-to-valley height to 3 nm. However, the surface still has the same undulating features (on a smaller length scale). Mesa diodes were fabricated from the grown GaN layers. The correlation between the diode electrical characteristics and GaN growth conditions is discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] InP DHBT circuits: From device physics to 40Gb/s and 100Gb/s transmission system experimentsBELL LABS TECHNICAL JOURNAL, Issue 3 2009Nils Weimann The capacity of fiber-optic telecommunication systems can be increased by higher data rate signaling. We present key analog and digital circuits which find application as building blocks in future very high data rate systems. The circuits are fabricated in our indium phosphide (InP) double-heterojunction bipolar transistor (DHBT) technology. The physical properties of the InP material system, notably high breakdown and high electron mobility, enable functions that are not accessible with current silicon-based high-speed technologies, including SiGe. Device and circuit results are presented, and we report on transmission system experiments conducted with these InP DHBT circuits. © 2009 Alcatel-Lucent. [source] Hydrogen- and carbon-related defects in heavily carbon-doped GaAs induced degradation under minority-carrier injectionELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 5 2010Hiroshi Fushimi Abstract GaAs/AlGaAs heterojunction bipolar transistors (HBTs) have attracted much attention because of their high-speed performance. However, long-term operation seriously degrades the device characteristics: the current gain decreases and the low-bias-leakage current increases. This degradation has long been an issue in GaAs-based devices operated under minority-carrier injection, such as laser diodes. The cause of degradation is thought to lie in the carbon-doped base, but this is not yet certain. In this paper the degradation of HBTs is described, especially that of GaAs/AlGaAs HBTs with a heavily carbon-doped base layer. Two types of device degradation are found, namely, hydrogen-related degradation and carbon-related degradation. The mechanisms governing the degradation are discussed in the framework of the recombination-enhanced defect reaction (REDR) and charge state effect (CSE). © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(5): 33,41, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10208 [source] Modelling and design considerations on CML gates under high-current effectsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 6 2005M. Alioto Abstract In this paper, the effect of the transit time degradation of bipolar transistors on the power-delay trade-off in CML gates and their design is dealt with. A delay model which accounts for the transit time increase due to the high bias current values used in high-speed applications is derived by generalizing an approach previously proposed by the same authors (IEEE Trans. CAD 1999; 18(9):1369,1375; Model and Design of Bipolar and MOS Current,Mode Logic (CML, ECL and SCL Digital Circuits), Kluwer Academic Publisher: Dordrecht, 2005). The resulting closed-form delay expression is achieved by properly simplifying the SPICE model, and has an explicit dependence on the bias current which determines the power consumption of CML gates. Accordingly, the delay model is used to gain insight into the power-delay trade-off by considering the effect of the transit time degradation in high-speed designs. In particular, the cases where such effects can be neglected are identified, to better understand how the transit time degradation affects the performance of CML gates for current bipolar technologies. The proposed model has a simple and compact expression, thus it turns out to be suitable for pencil-and-paper evaluations, as well as fast timing analysis. Simulations of CML circuits with a 20-GHz bipolar process show that the model has a very good accuracy in a wide range of current and loading conditions. Copyright © 2005 John Wiley & Sons, Ltd. [source] Thermal analysis of multi-finger GaInP collector-up heterojunction bipolar transistors with miniature heat-dissipation packaging structuresINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2010Pei-Hsuan Lee Abstract We build up a finite element modeling (FEM) approach to analyze the thermal performance of collector-up (C-up) heterojunction bipolar transistor (HBTs) with a heat-dissipation via configuration. Highly compact heat-dissipation packaging structures of GaInP/GaAs C-up HBTs have been designed and evaluated systematically. In this work, we devise the 2-D and 3-D models to simulate the actual devices and to investigate the temperature distribution behavior. Results from 2-D model indicate that the large heat-dissipation via configuration can be further reduced by 29% to meet the requirement of HBT-based small high-power amplifiers (HPAs) for the cellular phones. Furthermore, the demonstrated results show that the maximum temperature within the collector calculated from 3-D model is lower than that from 2-D model. In the 3-D analysis, it is revealed that the configuration can be reduced by 32%. Therefore, thinning the heat-dissipation via constructed underneath the GaInP/GaAs C-up HBT should be helpful for miniaturization of HBT-based HPAs in future mobile communication systems. Copyright © 2009 John Wiley & Sons, Ltd. [source] DC and small-signal comparison of horizontal emitter designs of InGaP/GaAs heterojunction bipolar transistorsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2009Juan M. López-González Abstract This paper describes the DC and small-signal performance of two InGaP/GaAs heterojunction bipolar transistors (HBTs) that have the same chip size. This is done in order to compare emitter,base designs using the TCAD ATLAS device simulator. The HBT devices analyzed have the same cutoff and maximum frequencies but significant differences are observed in other characteristics such as base,emitter turn-on voltage, saturation collector,emitter voltage, forward current gain, maximum transducer gain and maximum stable gain. Copyright © 2009 John Wiley & Sons, Ltd. [source] SPICE-aided modelling of dc characteristics of power bipolar transistors with self-heating taken into accountINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2009Janusz Zar Abstract This paper deals with the problem of calculations of the dc characteristics of power bipolar transistors (BJTs) with self-heating taken into account. The electrothermal model of the considered devices dedicated for PSPICE is presented. The correctness of the model was verified experimentally in all ranges of the BJT operation. Two transistors,BD285 and 2N3055,were arbitrarily selected for investigation. A good agreement between the measured and calculated characteristics of these transistors was observed. Copyright © 2009 John Wiley & Sons, Ltd. [source] A model for abrupt double heterojunction bipolar transistorsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2004Antonio J. García-Loureiro Abstract In this paper, we present a model for double heterojunction bipolar transistors (DHBTs) that takes into account Fermi,Dirac statistics as well as an arbitrary injection level. The most commonly used models in the literature for heterojunction bipolar transistors (HBTs), bipolar junction transistors (BJTs) and PN junctions can be easily obtained as a particular case of the general model presented here. In order to illustrate its features, the model is applied to an InP/GaAsSb/InP DHBT and an InP/InGaAs HBT. Copyright © 2004 John Wiley & Sons, Ltd. [source] Monte Carlo modelling of abrupt InP/InGaAs HBTsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 4 2003Pau Garcias-Salvá Abstract In this paper a Monte Carlo simulator which is focused on the modelling of abrupt heterojunction bipolar transistors (HBTs) is described. In addition, simulation results of an abrupt InP/InGaAs HBT are analysed in order to describe the behaviour of this kind of device, and are compared with experimental data. A distinctive feature of InP/InGaAs HBTs is their spike-like discontinuity in the Ec level at the emitter,base heterojunction interface. The transport of electrons through this potential barrier can be described by the Schrödinger's equation. Therefore, in our simulator we have consistently included the numerical solution of this equation in the iterative Monte Carlo procedure. The simulation results of the transistor include the density of electrons along the device and their velocity, kinetic energy and occupation of the upper conduction sub-bands. It is shown that the electrons in the base region and in the base,collector depletion region are far from thermal equilibrium, and therefore the drift,diffusion transport model is no longer applicable. Finally, the experimental and simulated Gummel plots JC(VBE) and JB(VBE) are compared in the bias range of common operation of these transistors, showing a good data agreement. Copyright © 2003 John Wiley & Sons, Ltd. [source] An accurate scaling approach for small-signal modeling of high-power HBT devicesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2007Sami Bousnina Abstract This paper presents an accurate scaling approach for small-signal modeling of high-power multi-cell heterojunction bipolar transistors (HBTs). This approach is mainly based on the characterization of an elementary-cell device and a proper modeling of the metalwork structure surrounding the transistor intrinsic part. The determined elementary-cell small-signal model is then scaled up to generate the S-parameters of the multi-cell device. An experimental validation was performed on a single-cell and three-cells GaAsHBT devices and excellent agreement was obtained between measured and simulated S-parameters over frequency range 1,15 GHz. This modeling approach is particularly useful for on-wafer characterization and modeling of high power HBT devices. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2429,2434, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22765 [source] High-gain high-isolation CMFB stacked-LO subharmonic gilbert mixer using SiGe BiCMOS technologyMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2007T. H. Wu Abstract A 5.2-GHz SiGe BiCMOS stacked-LO-stage CMFB (common mode feedback) subharmonic mixer is demonstrated in this article. The stacked-LO-stage and the active loads are used to improve the 2LO-RF isolation and the conversion gain, respectively. The SiGe mixer includes five levels of transistors stacked together at the supply voltage of 3.3 V because of the low knee-voltage characteristic of the SiGe HBTs (heterojunction bipolar transistors). The mixer demonstrated achieves 23 dB conversion gain and ,78 dB 2LO-RF isolation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1214,1216, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22398 [source] | ||||||||||