Noise in two-port devices with a negative input or output conductance

The noise figures of a two-port device with negative input conductance and of a two-port device with negative output conductance are calculated. It is shown that such devices, if developed, might open up interesting possibilities.     

Improving the ESD failure threshold of silicided n-MOS outputtransistors by ensuring uniform current flow

The authors describe and extend the present understanding of the high-current behavior of the simple single-poly finger n-MOS transistor. They present a model for the failure of the ladder structure n-MOS output device based on both the structure of the device and the behavior of its constituent n-MOS transistors. This model is able to show why the failure threshold of the output n-MOS device behaves as it does. Solutions that have been shown to improve the electrostatic discharge (ESD) failure threshold are described. The test environment and the process technology used for fabrication are described     

Large-signal analysis of semiconductor circuits with multifrequency excitation

A nonlinear device characterized by a noninteger power-law equation is considered. Amplitudes and phases of output harmonic and mixing components are determined for the case where the device is driven by several arbitrarily phased frequency components. The resulting expressions are shown to have close ties with the Gaussian hypergeometric function.     

The Forked Blazed Grating as a Quasioptical Element for Gyrotron Applications

In previous papers we have shown how beams of millimeter-wavelength electromagnetic radiation with phase singularities can be generated by diffraction from a specially-configured forked blazed grating. Here we consider how the hollow conical beam output of a gyrotron is diffracted by this kind of grating. Two applications are considered; using the grating (a) as a single-element quasioptical antenna to convert the output into a well-collimated gaussian-like beam and (b) as a device to enable the estimation of the fractions in oppositely-rotating modes in the gyrotron output.     

MOS-Based Spin Devices for Reconfigurable Logic

Semiconductor-based spin transistors are expected to give a new spin degree of freedom in future electronics. While many different spin transistors have been proposed and studied, the spin MOSFET is one of the most promising devices, because it can have spin-dependent output characteristics, transistor functions, and good compatibility with existing silicon technology. The device concept, structures of various types of spin MOSFETs, operation principles, calculated output characteristics, and applications was reviewed. It is shown that the output characteristics of the spin MOSFETs depend on the relative magnetization configuration of the two ferromagnetic layers in the device, that is, high current-drive capability in parallel magnetization and low current-drive capability in antiparallel magnetization. Furthermore, nonvolatile memory and reconfigurable logic gates was presented using spin MOSFETs, where the logic functions can be changed by switching their magnetization configurations. Circuit design and numerical simulations of reconfigurable gates for NAND/NOR, AND/OR, and all symmetric Boolean functions was shown     

60 GHz high-efficiency InP pulsed TEO

The letter describes the fabrication and assessment of indium phosphide devices designed for high peak-power pulsed operation at millimetre-wave frequencies. The importance of the cathode contact properties for this device are discussed, together with brief details of the n-n+ material growth parameters. An outline of the device fabrication technology is given before the resultant device RF performance characteristics are presented. It is shown that peak output powers as high as 1.2 W and DC to RF conversion efficiencies of up to 12% can be realised at 60 GHz.     

Optoelectronic Pulse Compression of Microwave Signals

Optically switched transmission line resonators are shown to generate short microwave pulses of higher output peak power than the CW input signal. This kind of pulse compression is achieved by using the resonator as a storage element and an optoelectronic switch as the output mirror. A theoretical analysis of the efficiency of this device is presented. Experimentally, a peak power enhancement of 14 has been observed at a frequency of 1 GHz. A comparison with numerical results is finally carried out.     

Analysis of the output conductance of insulated gate transistors

The output characteristics of insulated gate transistors (IGT's) are shown to be determined by the variation in the gain of the wide-base transistor in the device structure. Improvements in differential output resistance can be achieved by either decreasing the lifetime, as demonstrated in this paper by using electron irradiation, or by using a punchthrough base design.     

The scanistor—A solid-state image scanner

Scanistors form a new class of semiconducting devices which perform image scanning or dissection by reason of a novel electronic method of commutating a single output terminal to any preselected illuminated portion of the device. The selection is uniquely determined by a voltage applied across two terminals of the device. The present investigation is concerned with a strip-shaped unit called the multijunction scanistor which is comprised of a linear, integrated-circuit array of photodiodes. This device provides an output either as a sequence of pulses which represent spatial sampling of a line image at a discrete number of points, or as an analog wave-form which is a linear transformation of the line image. A theory appropriate to scanners of this type is developed and applied to the multijunction scanistor for purposes of design and analysis. A time-dependent circuit analysis of a model of the scanistor is carried out and tested experimentally. It provides an understanding of the upper limits to the scanning rate set by junction capacitance. Experimental units designed according to theory are tested for their sine-wave response, uniformity of output, sensitivity, and scanning linearity. These units are shown to give good results when used to scan a typewritten document for facsimile display on an oscilloscope.     

Numerical simulation of nonstationary electron transport in Gunn devices in a harmonic mode oscillator circuit

The behavior of GaAs Gunn devices in harmonic mode oscillator circuits is numerically simulated taking nonstationary electron transport into account, The output power and dynamic impedances of the Gunn device are calculated for different passive circuitries. It is shown that for maximum output power the passive circuitry should behave like a series resonant circuit.     

The klystrode—An unusual transmitting tube with potential for UHF-TV

Economic considerations, especially the increasing cost of energy, have forced electron power tube designers to revise current designs and to re-examine old ones. One result of this re-examination is the rebirth and improvement of a very old and largely forgotten device which appears to hold great promise as a generator of tens to hundreds of kilowatts in the UHF range, with special advantages in TV service. The device itself is described both theoretically and in practical terms, its performance to date and its calculated limits of power output are given, and examples of RF circuitry are shown.     

Digital signal transfer in charge-transfer devices

The nonlinear properties of digital signal transfer through charge-coupled device and bucket-brigade shift registers are considered in terms of adjacent bit charge levels. A signal transfer efficiency is defined and shown to be a useful parameter for charge-transfer device shift register simulation. Approximate equations are developed for the worst case output bit levels and an approximate formula for the optimum input `fat' zero level, with respect to the worst case output signal `window', is obtained. The analysis includes only the intrinsic incomplete charge transfer properties of CTD's under square-wave clock pulsing conditions. Comparison of the theory and preliminary experimental results for CCD indicate good quantitative agreement.     

A dual SQUID linearization concept using a phase modulation scheme

A critical control system evaluation is presented of basic flux-locked loop systems. The development of a new superconducting quantum interference device (SQUID) linearization method is then described, where no magnetic flux feedback is necessary to cancel the applied flux. It is shown that a dual SQUID configuration will be able to produce a true phase modulation system that is easily demodulated with a phase-locked loop. The theoretical performance of the proposed configuration is verified by simulations, and the performance and limitations are discussed in detail. It is shown that small dc correction voltages at the output of the SQUID's significantly decrease output noise, as is the case with an increase in SQUID dc bias currents. An optional feedback system is also described for optimal performance of the dual SQUID configuration     

定时输出电源控制装置软件设计

以单片机Mega16芯片为核心,以时钟专用芯片1307为时基,以高压光耦驱动大功率可控硅为执行器件,设计了一种多时段可调定时输出电源控制装置。在阐述了定时输出电源控制装置的整机工作过程的同时,重点分析了定时输出电源控制装置的软件设计。该装置用于定时段运行的大功率设备的电源控制,经实践应用证明,可减少工作量,节能减排,且效果良好。     

多状态反射计技术

本文讨论了多状态测试技术,并将它与多端口测试技术进行了比较,通过分析给出了多状态测试时的功率关系。最后给出了一个工作在毫米波波段的多状态反射计实例,所得结果是令人满意的。     

A simple two-dimensional model for IGFET operation in the saturation region

A model is developed for an IGFET operating in saturation and accounting for the two-dimensional potential distribution in the section of the surface space-charge region adjacent to the drain. This section is treated as a volume obeying Gauss's law, thereby enabling the charge contained in it to be related to the integral of the electric displacement density normal to its surface without the need to consider the detailed distribution of charge inside. The resulting model shows, explicitly, the dependence of device output characteristics on applied potentials, geometric and processing parameters. It is also shown that by making adequate approximations, simple yet accurate forms of the model are obtained. The accuracy of the model is demonstrated by comparisons between calculated and measured device output characteristics.     

Maximising performance of optical coherence tomography systems using a multi-section chirped quantum dot superluminescent diode

Key device requirements for maximising resolution in an optical coherence tomography system are discussed. The design and operating parameters of a multi-contact quantum dot superluminescent diode incorporating a number of features which inhibit lasing are described. Such devices allow the independent tuning of emission power and spectral shape; hence the penetration depth and resolution in optical coherence tomography are decoupled. The emission spectrum of a device utilising chirped quantum dots is shown to be tuned to produce a broadband single Gaussian emission, centred at the required wavelength of 1050 nm, with high output powers than a single contact device.     

3-D device modeling for SRAM soft-error immunity and tolerance analysis

Soft-error tolerance of static random-access memory (SRAM) devices has been predicted by using three-dimensional (3-D) and time-dependent device simulation in conjunction with circuit simulation. An inverter model developed for 3-D device simulation is described, along with the analysis of the inverters device response as a function of time. The output thus obtained was applied as an input voltage source in circuit simulation of unit SRAM cell and the stability of this bistable circuit is studied on that basis. The effects on soft-error immunity of changes in alpha-particle injection conditions and in load resistance and capacitance are described. The validity of the presented model is examined through comparison of the bit-error-rate dependence on incident angle of alpha particles to that of measured rates. To simulate the angular dependence, we introduce statistical distribution models for alpha-particle energy, position of incidence on the device surface, and angle of incident. Results of device/circuit simulation carried out with many sets of energy, position, and angle are presented. Reasonable agreement between results of simulation and experimental data without the use of adjustment parameters is demonstrated. A map of soft-error tolerance on the CR plane with critical charge Q/sub c/ as a parameter is presented and its derivation explained. An analytic expression for the tolerance is clarified by proposing an equivalent circuit model for the simulation of alpha-particle injection at the output node in an inverter circuit. Inverter modeling is shown to be essential to obtaining SRAM soft-error tolerance to high degrees of accuracy.     

A Microwave Ferrite Single-Sideband Modulator

A microwave single-sideband modulator has been designed utilizing two reflection types of Faraday rotation ferrite-balanced modulators. Power is fed to the two balanced modulators by means of a 3-db quadrature hybrid such that each modulator has equal incident power with a 90-degree phase difference. The output power of the balanced modulators is combined by means of a magic tee sum and difference circuit. It is shown that if the modulation signals applied to the balanced modulators are in phase quadrature, the upper sideband will appear at the output sum arm and the lower sideband will appear in the output difference arm. An analysis of the device relates the spurious and undesired sidebands to the conversion loss, and a method is proposed for minimizing carrier output. The drive power is reduced due to the use of reflection-type balanced modulators, and experimental data is presented for the modulation frequency impedance and drive power requirements. The temperature and frequency sensitivity of the undesired sidebands have also been measured. A number of applications of the device are discussed.