bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyses and experiments of nonlinear phenomena in piezoelectric semiconductors
Authors: Yamanouchi Kazuhiko , Inada Tsutomu 
Published: July 2007

AbstractSince a GaAs semiconductor has a piezoelectricity and a high mobility at the same time, it has attracted the attention of many research workers as material for surface‐acoustic‐wave (SAW) devices utilizing its nonlinearity. However, in published works, the analyses have regarded a semiconductor substrate as a piezoelectric element, or an epitaxial‐growth film as a semiconductor. Also, some analyses of a piezoelectric semiconductor were limited to a one‐dimensional model, or to obtaining the velocity and attenuation of the surface wave by using the perturbation method.In this paper, a numerical analysis of the SAW on a general piezoelectric element is carried out. The propagation characteristics of the SAW for the carrier density of a semiconductor, the convolution efficiency for the carrier density, and its dependence on the mobility represent new findings. Also, the results of analyses on a double‐layer are shown. Also, the experimental results of the excitation characteristics of an SAW on a GaAs piezoelectric element, and the output of the convolution relating to the carrier density are shown.
Recovery voltage in dielectric absorption of capacitors and consideration by using an equivalent circuit
Authors: Miyairi Keiichi , Yazawa Kazuhiro 
Published: July 2007

AbstractA voltage appearing between the electrodes of a charged capacitor, after it is discharged by short‐circuiting its electrodes, is known as a recovery voltage. A test method by which the dielectric absorption of a capacitor is calculated from its recovery voltage is described in the Japanese Industrial Standard (JIS). In this paper, the effect of the applied voltage, charging time, discharging time, and input impedance of a voltmeter, on the recovery voltage is investigated experimentally. The dielectric absorption is also investigated theoretically by using an equivalent circuit of the recovery voltage. It was found experimentally by using polystyrene capacitors that the greater the input impedance of the voltmeter, the greater the dielectric absorption calculated from the recovery voltage, and the shorter the discharge time, the greater the dielectric absorption. These relationships were confirmed by a computer simulation based on the above‐mentioned theory. It has been concluded that the input impedance of the voltmeter used for measuring the recovery voltage should be higher than the leakage resistance of the capacitor under test.
CR Low frequency tuned amplifier circuit with high selectivity
Authors: Ieyasu Kenzo , Kurokawa Susumu 
Published: July 2007

AbstractThe conductance of the reactance circuit used in the tuning circuit of the CR tuned amplifier is a function of frequency with negative minimum value. If the external parallel resistance to the tuning circuit is reduced so that a high selectivity is obtained, the conductance becomes negative at a frequency other than the resonance frequency and the circuit will oscillate. We have obtained a stable high‐gain tuned amplifier with high selectivity by selecting the values of resistor and capacitor in the voltage phase‐shift circuit so that the conductance of the tuning circuit is minimum at the resonance frequency. The amplifier with the resonance frequency of 10 kHz fabricated according to this design method exhibits the maximum selectivity of about 700 and the voltage gain of about 100 dB. These values agree well with the computed values. The rate of change of the resonance frequency for the temperature has been made rather small with the use of circuit components with small temperature coefficients. However, the rate of change of the gain (and hence selectivity) is extremely large. With the use of an ac resistive circuit with a positive temperature coefficient consisting of PTC thermistors and transistors, the rate has been reduced to the extent tolerable in the practical temperature range.
One‐dimensional table look‐up model for sub‐μm MOS transistors
Authors: Matsuo Hitoshi , Yokomizo Gooichi , Masuda Hiroo , Hagiwara Takaaki 
Published: July 2007

AbstractA highly accurate one‐dimensional table model has been developed for an MOS transistor simulation used in a circuit simulation necessary for the VLSI design. The usefulness of the model for the circuit simulation has been tested. Traditionally, the one‐dimensional table model has been used in the area where high precision is not required, such as the timing simulators. It is not sufficient for simulation of a high‐precision circuit and the accuracy has been a particular problem for the MOS transistor of submicron level. In the new one‐dimensional table model, the two‐dimensional effect of the drain and gate electric fields is included and only two one‐dimensional tables are added. The model can be applied to a high‐precision circuit simulation. This model has been applied to three devices with the effective channel length of 0.66 ∼ 2.30 μm fabricated in different processes. It was found that the maximum of the average relative error within the practical voltage range is 3.87% which corresponds to the acuracy four times that in the conventional model. Increase of the error for the variation of the substrate voltage is especially small. It has been demonstrated that the present one‐dimensional table model is a transistor model capable of high‐precision circuit simulation.
A current conveyor II realized by Mosfets and its application to switched capacitor filters
Authors: Gotō Naoki , Nishio Makoto , Suzuki Tokio 
Published: July 2007

AbstractFrom the viewpoint of intergration, a MOSFET configuration is superior to the previous current conveyors (CC) consisting of an operational amplifier and/or bipolar transistorsIn this paper, a current conveyor II (CC II) is composed of an operational amplifier and MOSFETs. It was clarified that the current transfer ratio from X terminal (input) to Z terminal (output) of CC II can be put to variable Ki., not to 1, because the MOSFET is a voltage‐controlled device. As a case of application, a switched capacitor (SC) integrator is realized with our proposed CC II and its transfer characteristic is studied theroretically and experimentally. Then, by applying this SC integrator to a Biquard‐type bandpass switched capacitor filter (SCF), it turned out that the electric capacitor of the SCF can be reduced largely and the SCF integration is superior in this regard.
Printing properties of two‐color laser beam printer
Authors: Hoshi Nobuyoshi , Anzai Masayasu , Akimaru Susumu , Komatsu Isamu 
Published: July 2007

AbstractIn operation of a laser beam printer to print a two‐color image with one rotation of a photoconductive drum by twice exposing the negative and reversal development of the image undesirable color mixing occurs. This is due to the fact that the first color toner is mixed into the second color developer by the magnetic brush of the printer and the mixed first toner is developed with the second color toner. This paper describes a method of inhibiting the color mixing by reversing the electrostatic charge polarity of the mixed toner so that it can be separated. It is possible to reverse the charge polarity of the first color toner mixed into the second color developer by utilizing its friction against the second color toner in a developing process which uses the same carrier for the first and second color developers. The mixed toner with its charge polarity reversed is separated from the second color toner by the electric field of the electro‐static latent image during its developing and remains on the nonimage part of the photoconductor, being finally removed with the photoconductor.
High‐speed logic circuits combining bipolar and CMOS technology
Authors: Masuda Ikuro , Nishio Yoji , Ikeda Takahide 
Published: July 2007

AbstractIt has been verified that a new LSI concept with high speed and low power consumption can be realized by combining bipolar and CMOS technology inside a basic unit circuit. This paper proposes a combined basic circuit that is of the high‐speed logic type. It is theoretically and experimentally evaluated to show that specified performance can be obtained, and some effective applications are analyzed. Using the circuit model, the relatioship between the performance of logic cicuit and the basic characteristics of the devices are analyzed, and the collector current vs. fT characteristics of bipolar device is shown to be important. Ring oscillators are fabricated for the two concrete circuits, and the speed and power conssumption are evaluated. The fabrication uses a newly developed Bi‐CMOS 2 μm technology which has buried layer and a small‐sized emitter for bipolar device with good high frequency characteristics. As a result, with a standard load and operation frequency, the delay of 0.7‐0.8 ns, and the power consumption of 0.15‐0.25 mW are obtained. By applying this logic circuit to gate arrays and memories, twice the speed of a CMOS can be realized with the same amount of power consumption.
Linearization of a light emitting diode for analog baseband video transmission
Authors: Nakamura Masaru , Nitta Koichi , Komatsubara Tadashi , Okajima Masaki , Ozeki Takeshi 
Published: July 2007

AbstractNonlinearity compensation is very important when using an LED source for video transmission. In general, wideband negative optoelectronic feedback makes a high‐quality, low‐distortion, adjustment‐free light source possible. However, when attempting to apply this technique to the LED, a stable feedback loop design is difficult to achieve because of the poor coupling efficiency between the LED and the external photodetector. We have resolved this problem via a monolithic integration of the LED and PD, and realized a low‐distortion LED by the addition of an external negative feedback circuit. The LED, PD composite device is a hybrid fabricated with LPE for the LED and MOCVD for the PD. A signal transmission efficiency of 2 percent was achieved between the LED and PD. This is more than an order of magnitude larger than the efficiency attainable with conventional discrete components, and rivaling what can be done with an LD. Evaluation of the video transmission quality showed an improvement in the differential gain and phase from 8 percent and 2.5° to 1 percent and 0.5°, and also automatic compensation was available for line and frame slope and improved frequency response flatness in the passband. With this method of LED distortion reduction, the conventional predistortion or frequency compensation circuits and their adjustments are no longer necessary, and a low‐cost, high‐quality LED source becomes possible.
Video frequency active filters using balanced‐type NICs
Authors: Kumazawa Masazumi , Yanagisawas Takeshi 
Published: July 2007

AbstractMost proposed methods of constructing active filters are limited to the audio‐frequency band. This paper describes an LC simulation type video‐band active filter using the excellent high‐frequency characteristics of the balanced‐type negative‐impedance converter (NIC)After describing the construction method of a balanced‐type NIC, the nonideal components which affect the characteristics of the filters are analyzed. A dc‐bias method for a gyrator using the proposed NIC is also shown. Taking the 4th‐order BPF and the 5th‐order LPF as examples, a method of constructing video‐band active filters and a method of filter compensation are shown. These methods require fewer active elements than usual and utilize npn transistors alone so that they are suitable for monolithic ICs. The results of the experiments using standard transistor‐arrays with simple compensation agree well with the theory in the frequency band up to 10 MHz.
Five‐layer structure electroluminescent devices prepared by RF sputtering
Authors: Mikami Akiyoshi , Ando Keiichi 
Published: July 2007

AbstractFive‐layered electroluminescent (EL) devices having an active ZnS:TbF3 layer sand‐wiched by an insulating layer and a low‐resistive Ta2O5 layer were produced, and luminous characteristics were investigated. It was found that these devices provide high brightness and luminous efficiency compared with the conventional three‐layered El devices, as well as low driving voltage. This is because the low‐resistive layer between the active layer and the insulating layer is important in improvement of crystallinity of the active layer, increase of conduction carriers in the active layer, and improvement of device breakdown voltage which enables a thinner insulating layer compared to the three‐layered structure. Bright green electroluminescence exceeding 1000 cd/m2 at 90 V and threshold voltage of 68 V have been obtained under 5‐kHz sinusoidal voltage excitation.
Improved pulse‐width‐modulation D‐A converter
Authors: Yoshida Takashi , Nakagawa Masao , Tsunogaes Toshio 
Published: July 2007

AbstractWith all of the recent technological advances in electronics, the problem of interfacing between digital and analog signals is of great importance. Many different principles for Digital‐to‐Analog Converters (DAC) exist; this paper proposes a new Pulse Width Modulation (PWM) type DAC. With conventional PWM DACs only a simple circuit is needed to realize high resolution; however, the necessary Low Pass Filter (LPF) at the output makes them unsuited for high‐speed operation. Accordingly, we consider here a PWM DAC in which the PWM pulse is separated into component pulses to allow the LPF cutoff frequency to be raised for higher‐speed operation. In this Separated Pulse Width Modulation (SPWM) DAC technique there is no need to convert serial digital input into parallel, so the circuitry can remain simple. Here we report on the principle of the SPWM method, the DAC design philosophy, and on experimental confirmation of its performance.
A new cut of quartz for SAW devices with extremely small temperature coefficient by leaky surface wave
Authors: Shimizu Yasutaka , Tanaka Masafumi 
Published: July 2007

AbstractSAW devices are widely used as delay lines, oscillators and filters. Their characteristics are mainly determined by the SAW propagation characteristics on the piezoelectric substrate. This paper seeks to find a cut that produces better characteristics than those of the conventional Rayleigh wave. Theoretical and experimental investigations are conducted for the characteristics of leaky surface waves propagating on a quartz substrate. As a result, an extremely desirable cut is identified which is a θ = 14.7° cut from a rotated Y‐cut X‐propagation substrate. This cut has a zero temperature coefficient, the variation of the delay time is less than ±10 ppm over a wide temperature range of −20 ˜ 80°C, the propagation loss is only 2.6 × 10−3 dB/λ and the propagation velocity of about 3940 m/s is much higher than that of an ST cut. This new cut is considered to be sufficiently practical for application to various SAW devices.
A two‐dimensional reliability simulator (2P/IMPAC) and its application to LDD MOS devices
Authors: Onga Shinji , Wada Masashi , Konaka Masami 
Published: July 2007

AbstractA new two‐dimensional reliability simulator 2P/IMPAC has been developed in which a two‐dimensional process simulator and a two‐dimensional device simulator for inspecting the substrate current are combined in a file link method. In the process simulator part, lithography, oxidation, diffusion, ion implantation, film deposition and etching are modeled. Hence, the impurity profile and the fabricated device shape can be derived. In the device simulation part, the Poisson equation and the current continuity equation are solved simultaneously with a repetitive numerical method based on the results of the process simulation, and the electrical characteristics of the MOS device can be calculated. This system is used for finding the relation between the electrical characteristics and the process parameters of the n− region formation in an LDD (Lightly Doped Drain) device from the viewpoint of longterm reliability of MOS devices.
Seed crystal in growth of KDP single crystal for optical harmonic generation
Authors: Shimomura Osamu 
Published: July 2007

AbstractA large single‐crystal KDP with a radius larger than 35 cm is needed in laser fusion as a conversion device of the laser wavelength to a shorter one. Since the growth speed of KDP single crystal is slow and hence a long time is required for growth, reduction of the growth time is important. The orientation of the seed is studied for both Type I and Type II of the phase matching. For the (001) and (101) plates, it has been found that less weight of the crystal is needed for a desired crystal plate from the seed of (101) plate than (001) plate in the range of θm > 23.7° for Type I and θm > 11.6° for Type II where θm is the phase matching angle. It has also been found that the growth time can be reduced with a (101) plate regardless of θm. For example, in the case of SHG of a glass laser at λ = 1.06 μm, the growth is only 54.4% for Type I and 33.8% for Type II with a (101) plate as a seed compared to a (001) plate.
Static analysis of a resistor‐load‐type D2 CMOS (dual depletion CMOS) associative memory cell by using the state diagram method
Authors: Yoshida Masahiro , Yoneyama Masao 
Published: July 2007

AbstractIn addition to functions required for conventional RAM cells, an associative memory cell requires a function for interrogating its input information and memory information. These requirements increase the number of components per bit, and create the problem of increased cell area when the components are integrated. This paper proposes a new associative memory cell using dual depletion CMOS (D2 CMOS) devices which have fewer components per bit than conventional associative memory cells so that they are more suitable for an integration. By using “the state diagram method,” the static characteristics of the cell were analyzed. The conditional equations of the load resistance which makes the cell functional as an associative memory were obtained and the memory characteristics examined. The writing characteristics involving the conditions for the shift of a state and the writing voltage also were analyzed. In addition, the reading characteristics and the interrogating characteristics were examined. The results of the analyses agree fairly well with the results of the simulation using the circuit analysis programme SPICE 2.
Two‐dimensional mode analysis of a Raman‐type free‐electron laser using a TM pump wave
Authors: Kondo Harufusa , Shiozawa Toshiyuki , Ishido Yoshinari 
Published: July 2007

AbstractWe consider a two‐dimensional Ramantype free‐electron laser composed of a relativistic electron beam with arbitrary thickness drifting in a parallel plate waveguide. For the Raman‐type free‐electron laser specified, we analyze the case where the pump wave is an electromagnetic wave of the TM mode, comparing with the case of the TE pump wave. First, we derive the coupled mode equations relating the scattered wave and the electron plasma wave. By imposing the boundary conditions at the beam surface upon the solutions to the coupled mode equations, we find the dispersion relation for these waves, from which we obtain the spatial growth rate for them. Then, we investigate in detail the frequency and growth rate of the scattered wave, with the aid of numerical illustrations. For the case of the TM pump wave, the boundary conditions at the beam surface and the coupled mode equations in the electron beam become much more complicated than those for the case of the TE pump wave. As a result, the growth rate of the former case shows a considerably different behavior as compared with the latter case. In particular, we can obtain a greater growth rate for the case of the TM pump wave. In addition, the TM pump wave is found to be more advantageous for suppressing the oscillation of higher‐order modes because we can reduce the separation between conducting walls of the waveguide for this case.
On radiation from a relatively sharp bend of step‐index single‐mode optical fibers
Authors: Morita Nagayoshi , Tanaka Toshiaki , Kumagai Nobuaki 
Published: July 2007

AbstractThe problem of radiation from a uniform bend of a step‐index single‐mode fiber is theoretically investigated with the emphasis on derivation of a rigorous expression of the radiation field. The expression for radiation can be applied to a relatively sharp bend in which the modal field profile in the fiber cross section at the bend is different from the one in the straight section. Theoretical equations for the radiation pattern and the radiation loss are also given. Numerical examples for these quantities are shown in comparison to those obtained by neglecting the change of the field due to the bend. The application limit of the present expression for the radiation field is studied from the point of the geometrical optics. It is shown that the present results are applicable if the radius of curvature is more than 0.5 ∼ 1 cm when the wavelength is 1.55 μm and the core diameter is 9.8 μm.
High resolution polysiloxane electron resist
Authors: Naraoka Kiyotake 
Published: July 2007

AbstractIn electron beam lithography, patterning of submicron geometry is not easy because of electron beam backscattering from the underlying substrate. To solve this problem, the use of multilayer resist structure of irradiation dose correction is inevitable. In this work, the electron beam exposure characteristics of polysiloxane resist which is promising as an upper resist in two‐layer resist systems are examined. It has been found that for the polysiloxane resist with molecular weight of several 10,000, the film thickness is increased in the exposed area by exposure alone. The reason for this increase has been found to be the swelling due to the penetration of liquid‐state polymer with molecular weight of less than 10,000 ‐ 20,000 into the network crosslinking structure formed by the exposure. Therefore, a polymer with molecular weight (μMn) of 200,000 is appropriate for a practical polymethysiloxane resist, with sensitivity of 0.3 μC/cm2 (10 keV). This resist can resolve 1 μm line and space, and is promising for submicron fabrication.
Driving conditions and signal treatment method of the buried channel CPD image sensor
Authors: Kozono Toshiyuki , Matsuda Yuji , Senda Koji , Terakawa Sumio , Takamura Tohru , Kunii Takao 
Published: July 2007

AbstractThis paper examines the CPD (charge priming device) ‐ type solid‐state image sensor (MN8210), which has the image size of 2/3 inch, 398 (H) × 496 (V) pixels and horizontal overflow drain structure. Discussions are made on the driving and signal processing methods, which are effective in improving the vertical transfer efficiency and the noise characteristics. By injection driving using externally injected charge, the vertical transfer efficiency can be improved up to 95 percent, independently of the signal magnitude. By using the CDS (correlated double sampling) signal treatment method, the low‐frequency noise component generated in FDA (floating diffusion amplifier) is reduced by approximately 5 dB. By the signal treatment method which picks up only the photosignal component in the two output, waveforms noise reduction of 3 dB could be achieved.