D-MOS transistor for microwave applications

A new n-channel silicon MOS transistor is described that can be fabricated with channel lengths of less than 1 µ by using a double-diffusion process similar to that used in bipolar transistor fabrication. The dimensional tolerances are not tighter than those used in the processing of conventional MOS transistors. This device (called D-MOST) shows gain in the GHz range and a noise figure comparable to that of microwave transistors. The fmaxis 10 GHz and the noise figure is 4.0 dB at 1 GHz. A brief theory of the D-MOST is followed by the design considerations for a discrete microwave device. Results from s-parameter measurements in the range of 0.1-2.5 GHz are presented along with graphs showing the gains and the stability factor. A simple equivalent circuit is derived from the measurements. Applications of the D-MOST are described.     

Integrator circuit with bipolar transistor for Gbit/s applications

A novel continuous time integrator circuit suitable for Gbit/s signal processing is presented. It takes advantage of the inherent low impedance characteristic of broadband transistors. Instead of charging a capacitor from a high impedance current source, basically an inductance is used which is driven by a low impedance voltage source.<>     

Heterojunction bipolar transistor design for power applications

Design rules of AlGaAs-GaAs heterojunction bipolar transistors for power applications are presented and compared to those for Si microwave power transistors. Concepts discussed include the tradeoff between power gain, output power, power-added efficiency in the layout design, layer structure selection, and thermal design     

Saturated inverted transistor modeling for small-signal applications

The modeling and utilization of an inverted integrated n-p-n transistor as a controllable small-signal resistance is explored. A theoretical relation for inverse transistor saturation resistance is developed using a modified Gummel-Poon (G-P) model, and the results are compared to experimental measurements. The relation of inverse beta to the inverse saturation resistance is derived and modeled, as well as the effect of base charge, and bulk resistance. The factors governing the matching of saturation resistance between devices on the same chip and from lot-to-lot are investigated and compared to matching measurements. A noise model for the saturated inverted device is developed and noise measurements appear to confirm the model's validity. Finally, the application of this device to a programmable attenuator circuit is discussed and attenuation and harmonic distortion data are presented.     

RF LDMOS功率晶体管及其应用

论述了 RF LDMOS功率晶体管的基本结构和特点。从与双极晶体管相比较的角度 ,讨论了这种器件的优异性能。对其发展动态和应用情况作了介绍。     

A new trench bipolar transistor for RF applications

A new vertical trench SiGe heterojunction bipolar transistor (HBT) is proposed that improves the tradeoff between the cutoff frequency (f/sub T/) and the off-state collector-base breakdown voltage (BV/sub cbo/). Extensive device simulations show that a record f/sub T//spl middot/BV/sub cbo/ product of about 2375 GHz/spl middot/V can be obtained for an HBT having a trench field plate connected to the emitter and a linearly graded doping profile in the collector drift region, while about 700 GHz/spl middot/V can be obtained for a standard optimized HBT. This large improvement is explained mainly by the suppression of the base-widening effect.     

A silicon medium-power transistor for high-current high-speed switching applications

A diffused base, diffused emitter, n-p-n silicon switching transistor has been developed for high-current applications such as switching magnetic memories. The transistor is designed to operate as a switch at the 0.75- ampere level. For a collector current of 0.75 ampere, the large signal current gain is 20 and the saturation voltage drop 4 volts. The breakdown voltages are 75 volts collector-to-base, and 6 volts emitter-to-base. The unit shows fast switching characteristics. The rise, storage, and fall times are each of the order of 0.1 µsec. It has a common emitter unity gain frequency greater than 50 Mc. The transistor employs a localized emitter produced by photoresist techniques and oxide masked diffusion. Lead attachment is accomplished by compression bonding. The silicon wafer is bonded through a molybdenum intermediary to a massive copper stud. The design theory of the device, and the variation of device characteristics with temperature are given. The applicability of this devices to RF amplifier service is also discussed.     

Long-channel field-effect transistor with short-channel transistor properties

The typical parameters of samples of long-channel field-effect transistors and the results of measurement of their functional characteristics are presented. The possible distributions of the carrier mobility over the channel thickness are considered. The current-voltage characteristics of long-channel field-effect transistors with an arbitrary doping profile and carrier-mobility gradient are theoretically analyzed taking into account carrier velocity saturation.     

Organic field-effect transistor based sensors with sensitive gate dielectrics used for low-concentration ammonia detection

A novel organic field-effect transistor (OFET)-sensor concept is presented based on the application of an ion-conducting organic dielectric material, which is chemically adapted to change its electronic properties upon contact with an analyte, thereby generating an electrically detectable response. By employing pH-sensitive, ring-opening metathesis polymerized materials as gate dielectrics in bottom-contact OFETs with a meander-shaped top-gate structure, the concept was successfully realized and evaluated with ammonia (NH₃) as gaseous analyte, easily providing distinct sensor response at concentration levels as low as 100 ppm. In addition to current–voltage OFET-analysis, optical spectroscopy and capacitance measurements were used to rationalize the underlying sensor mechanism, which is mainly attributed to a deprotonation of the pH-sensitive groups of the active-sensing dielectrics by NH₃ and a resulting generation of mobile ions, leading to an increase of the charge carrier density within the OFET channel. The proposed concept provides several advantages over existing OFET-sensor detection principles, including the separation of the sensing mechanism from the charge-transport functionality of the semiconductor, inherent protection of the latter against air exposure and increased selectivity by the application of specific dielectric materials. It therefore offers a great deal of promise in contributing to the development of cheap, integrated, smart and flexible (bio)sensor systems.     

Switching speed of a transistor used as an AND gate

The limits of the switching speed of a single-transistor AND gate are discussed. This investigation includes a treatment of a transient `leakage? current condition which can occur in other applications of transistors.     

Parasitic resistance in an MOS transistor used as on-chipdecoupling capacitance

Adding on-chip decoupling capacitance has become a popular method to reduce dI/dt noise in integrated circuits. The most area-efficient realization of on-chip capacitance in a standard CMOS process is to use the gate capacitance of MOS transistors. In this paper, the inevitable parasitic resistance of an MOS transistor is estimated, which is important for two reasons. The resistive noise caused by this parasitic must be kept low, and, if properly sized, this resistance can be used to dampen potential resonance oscillations     

Study of the electrolyte-insulator-semiconductor field-effect transistor (EISFET) with applications in biosensor design

This paper presents a comprehensive review of the ion-sensitive field-effect transistor (ISFET) and its applications in biomolecular sensing and characterization of electrochemical interfaces. An introduction to the physics of field-effect transistors is presented, followed by a study of the properties of electrolytic solutions and electrolyte interface surface effects. Full modeling of the ion-sensitive transistor is given, followed by a survey of the different uses of the ISFET in biomedical and environmental applications. Particular attention is given to the use of the ion-sensitive transistors as replacements for microarrays in DNA gene expression analysis.     

Design and applications of 2-6.5 GHz transistor amplifiers

Using the microwave thin-film technology, the class-A common emitter transistor pre- and power amplifiers fabricated on a sapphire substrate were initially optimized for the gain and VSWR's simultaneously over the 2-6.5 GHz range and then adjusted for the large-signal conditions. The large-signal adjustments were proven to be quite beneficial in maximizing the power-handling capability and in minimizing the spurious signal content. The measured power gain of both amplifiers is 4 dB. The output power at the 1 dB gain compression level of pre- and power amplifiers is 13 and 16 dBm, respectively, while all spurious signals are at lease 20 dB down. Also, their applications in C-band test instruments are given.     

Two-dimensional metal-semiconductor field effect transistor forultra low power circuit applications

We describe a novel 2-dimensional metal-semiconductor field effect transistor (2-D MESFET) in which opposing Schottky side gates formed on the sidewall of a modulation-doped AlGaAs-InGaAs heterostructure modulate the channel width and the drain current. The drain current ranged from 0 to 210 μA and the maximum measured transconductance was 212 μS (212 mS/mm) at room temperature for a 1×1 micron channel. The threshold voltage was -0.45 V and the subthreshold ideality factor was 1.30. The estimated gate capacitance was 0.8 fF/μm, or about half the equivalent capacitance of conventional HFET's. The cutoff frequency f_T was estimated to be 21 GHz. The narrow channel effect, which limits the minimum power consumption in conventional FET's, is practically eliminated in this device     

Coupled-quantum-well field-effect resonant tunneling transistor formulti-valued logic/memory applications

A vertical field-effect resonant tunneling transistor is demonstrated consisting of a triple-barrier, double-well resonant tunneling diode (3bRTD) that can be depleted by the action of side gates. The 3bRTD features a double peak current-voltage characteristic in which the second valley current is less than the first valley current. Combination of the resonant tunneling transistor and a constant current load is shown to yield both binary and ternary logic and memory functions     

The importance of the non-quasi-static bipolar transistor model forcircuit applications

The need for non-quasi-static bipolar models is examined from a practical viewpoint in order to optimize compensation capacitor value, improve performance, and reduce chip area. This need depends on the circuit under study. The utility of non-quasi-static equivalent circuits in small-signal applications is investigated. The circuit example studied is a lateral p-n-p transistor used as a series pass transistor in a series voltage regulator. For the series voltage regulator, the non-quasi-static inductance model correctly predicts the rapid falloff of the magnitude of the current gain and thus reduces the required internal compensation and subsequent circuit area     

瑞芬太尼复合异丙酚在儿童淋巴管瘤穿刺治疗术中的临床应用

目的：观察比较芬太尼与瑞芬太尼复合异丙酚用于儿童淋巴管瘤穿刺治疗术的麻醉效果。方法：120例6月～3岁患儿随机分为F（芬太尼）组、R（瑞芬太尼）组,均复合丙泊酚麻醉。记录术中并发症发生情况及苏醒时间情况。结果：两组体动发生率、苏醒时间比较差异有统计学意义（P〈0.05）。结论：瑞芬太尼复合异丙酚应用于儿童淋巴管瘤穿刺治疗术镇痛、镇静效果好、苏醒时间短。     

High electron mobility transistor lightwave receiver for broad-bandoptical transmission system applications

The design and construction of a broadband transimpedance lightwave receiver which features packaged, commercially available high-electron-mobility transistors is described. The receiver was constructed on a standard teflon printed circuit board with packaged tailed 30-μm-diameter germanium avalanche photodiode as photodetector. A sensitivity of -25.5 dBm for 10^-9 bit error rate was achieved at 1.31 μm with a 5-Gb/s nonreturn-to-zero pseudorandom sequence provided by a commercial data generator and 1:4 analog demultiplexing at the receiver output