3,861 research outputs found
Proceedings of the Cold Electronics Workshop
The benefits and problems of the use of cold semiconductor electronics and the research and development effort required to bring cold electronics into more widespread use were examined
Fast physical models for Si LDMOS power transistor characterization
A new nonlinear, process-oriented, quasi-two-dimensional (Q2D) model is described for microwave laterally diffused MOS (LDMOS) power transistors. A set of one-dimensional energy transport equations are solved across a two-dimensional cross-section in a “current-driven” form. The model accounts for avalanche breakdown and gate conduction, and accurately predicts DC and microwave characteristics at execution speeds sufficiently fast for circuit simulation applications
When self-consistency makes a difference
Compound semiconductor power RF and microwave device modeling requires, in many cases, the use of selfconsistent electrothermal equivalent circuits. The slow thermal dynamics and the thermal nonlinearity should be accurately included in the model; otherwise, some response features subtly related to the detailed frequency behavior of the slow thermal dynamics would be inaccurately reproduced or completely distorted. In this contribution we show two examples, concerning current collapse in HBTs and modeling of IMPs in GaN HEMTs. Accurate thermal modeling is proved to be be made compatible with circuit-oriented CAD tools through a proper choice of system-level approximations; in the discussion we exploit a Wiener approach, but of course the strategy should be tailored to the specific problem under consideratio
Boundary layer flow and heat transfer over a permeable shrinking sheet with partial slip
The steady, laminar flow of an incompressible viscous fluid over a shrinking permeable sheet
is investigated. The governing partial differential equations are transformed into ordinary differential
equations using similarity transformation, before being solved numerically by the shooting method. The
features of the flow and heat transfer characteristics for different values of the slip parameter and Prandtl
number are analyzed and discussed. The results indicate that both the skin friction coefficient and the heat
transfer rate at the surface increase as the slip parameter increases
A Wideband 77-GHz, 17.5-dBm Fully Integrated Power Amplifier in Silicon
A 77-GHz, +17.5 dBm power amplifier (PA) with fully integrated 50-Ω input and output matching and fabricated in a 0.12-µm SiGe BiCMOS process is presented. The PA achieves a peak power gain of 17 dB and a maximum single-ended output power of 17.5 dBm with 12.8% of power-added efficiency (PAE). It has a 3-dB bandwidth of 15 GHz and draws 165 mA from a 1.8-V supply. Conductor-backed coplanar waveguide (CBCPW) is used as the transmission line structure resulting in large isolation between adjacent lines, enabling integration of the PA in an area of 0.6 mm^2. By using a separate image-rejection filter incorporated before the PA, the rejection at IF frequency of 25 GHz is improved by 35 dB, helping to keep the PA design wideband
A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier
Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages from 2.9 V to 5.5 V in a standard micro-lead-frame package. It shows no oscillations, degradation, or failures for over 2000 hours of operation with a supply of 6 V at 135° under a VSWR of 15:1 at all phase angles and has also been tested for more than 2 million device-hours (with ongoing reliability monitoring) without a single failure under nominal operation conditions. It produces up to +35 dBm of RF power with power-added efficiency of 51%
Radiation effects in high speed III-V integrated circuits
The article of record as published may be found at http://dx.doi.org/10.1142/S0129156403001612International Journal of High Speed Electronics and Systems, v. 13, p. 277 (2003).The types of applications affected by radiation effects in W-V devices have significantly changed
over the last four decades. For most applications W-V ICs have provided sufficient radiation
hardness. Some expectations for hardened soft error applications did not materialize until much later.
Years of research defined that not only material properties. but device structures. layout practices
and circuit design influenced how m-v devices were susceptible to certain radiation effects. The
highest performance ill-V ICs due to their low power-speed energy products will provide challenges
in ionizing radiation environments from sea level to space
High efficiency, low offset voltage InGaP/GaAs power heterostructure-emitter bipolar transistors with advanced thermal management
High efficiency, low offset voltage InGaP/GaAs power heterostructure-emitter bipolar transistors (HEBTs) have been demonstrated. The large signal performance of the HEBTs is characterized. Output power of 0.25 W with power added efficiency (PAE) of 63.5% at 1.9 GHz has been achieved from a 26-finger HEBT with total emitter area of 873.6 μm2. Output power of 1.0 W with PAE of 63% has been obtained from the composition of four above-mentioned power cells at the optimum conditions of impedance matching. The thermal performance of HEBT is presented and the results show better thermal management than conventional HBT. The experimental results demonstrate good power performance and capability of HEBTs.published_or_final_versio
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