bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy transmission of switched‐capacitor circuit and application to dc‐dc converter
Authors: Shibata Kimihiko , Emura Minoru , Yoneda Shojiro 
Published: July 2007

AbstractThe switched capacitor (SC) circuit has been applied to analog signal processing, but few reports have been made on the application to power circuit. Recently, a report has been made on the dc‐dc converter using the SC circuit, but the circuit still has a number of problems, e.g., the loss due to the switching element or equivalent resistance of the SC circuit, the output ripple and the noise.From such a viewpoint, this paper presents first the theoretical and experimental investigations on the energy loss, energy transmission efficiency and output power of the dc‐dc converter using the basic SC circuit. Based on that result, dc‐dc converters are considered using a series‐parallel switching SC circuit with more than one capacitor. It is seen as a result that the loss due to the equivalent resistance is inevitable, even if ideal switching elements or capacitors are used in those SC circuits.As a means to cope with this problem, the dc‐dc converter using a new SC circuit is proposed, where the zero‐voltage switching mechanism is employed using a high‐frequency supply and the peak‐detector circuit. It is shown theoretically that the loss due to the equivalent resistance is not produced in principle in the proposed SC circuit. A result of experiment is shown with a drastic improvement.
Preparation and characterizations of Al12 W intermetallic compound film by Co‐sputtering
Authors: Sasaki Katsutaka , Noya Atsushi 
Published: July 2007

AbstractAn Al12W intermetallic compound film was formed by the co‐sputtering method for the development of Si‐LSI metallization technology. The condition to form a stoichiometric Al12W film, its electrical properties and surface characterizations were investigated. As a result, when a film deposited on an unheated substrate was annealed at a temperature above 400d̀C, it recrystallized and became a stoichiometric Al12W intermetallic compound.The resistivity and temperature coefficient of resistance for an Al12W intermetallic compound film were 45 μω‐cm and 800 ppm/d̀C, respectively. Since the film resistivity is low compared with those of many other intermetallic compounds, it is expected to be useful as metallization material for an Si‐LSI. When the film is exposed to air, Al atoms segregate and become oxidized, resulting in the formation of a thin Al2O3 formed is at most 100 Å even after annealing in air at 440d̀C, the surface oxide layer is expected to be a passivation layer.
Boundary‐element method analysis of light‐beam scattering and the sum and differential signal output by DRAW‐type optical disk models
Authors: Kojima Toshitaka , Ido Jun 
Published: July 2007

AbstractThis paper assumes a simple model for the DRAW (direct‐read/after‐write) optical disk using a Te‐alloy recording medium. The scattering of the light‐beam by the pit or boss of arbitrary shape on the boundary of three‐layered dielectrics is analyzed by the boundary‐element method. The sum and the differential signal output characteristics of the two‐split‐type optical detector also is discussed. The results of simulation are shown for the effect of the adjacent pit in the square and V‐shaped pregrooved models, the dependencies of the sum and the differential signals on the tracking error, and the dependencies of the sum and the differential signals on the pit depth, when the signal recording pit is provided in the two types of pregrooved models.
Noise characteristics of NbN nanobridge dc SQUIDs fabricated by field emission technique
Authors: Nagaoka Shiro , Irie Akinobu , Hamasaki Katsuyoshi , Yamashita Tsutomu 
Published: July 2007

AbstractNbN nanobridge dc SQUIDs were fabricated by the field evaporation method and their noise characteristics were evaluated. The fabricated device has a magnetic flux‐voltage conversion efficiency Φ of about 2.5 mV/Φ0 and hence the device has a higher gain than that of the tunneling‐type device with a resistive shunt. The energy resolution is as small as 40 h. When the fabricated SQUID was installed in an FLL circuit and the dynamic range was measured, it is found that an output is proportional to the input for the input magnetic flux of ±32Φ0 without removing the lock. The magnetic flux resolution of the FLL circuit used is 9 × 10−10 Φ02/Hz in the white noise region (at 3 kHz). In the low‐frequency region less than 100 Hz, the 1/f noise described by 5.8 × 10−8 (1/f)Φ02/Hz was observed. This value of the magnetic flux resolution is large by one order of magnitude than that inherent to the device and the noise of the electronics is predominant.
Polarization‐independent guided‐wave optical hybrid coupler
Authors: Haga Hiroshi , Negami Takayuki , Yamamoto Sadahiko 
Published: July 2007

AbstractA new guided‐wave hybrid coupler is proposed and its operating analysis is described. The device structure resembles that of a conventional directional coupler. It consists of a parallel portion in which two waveguides, with identical phase constants, are placed closely in parallel and of input and output sections, in which two waveguides separated sufficiently to allow input and output from other devices, adjoin the parallel portion. Although one of the input‐output sections is symmetric with the phase constants of the two waveguides equal, another has a nonsymmetric structure with different phase constants. The optical wave coupling in this non‐symmetric part plays an important role for the device operation.In the analysis of operation, the coupling coefficient and difference of the phase constants between the waveguides are used as the waveguide parameters. The range of these parameters was obtained as necessary for stable operations in terms of difference in polarization and fabrication errors. It is shown that a rather large coupling coefficient and a large phase constant difference are needed in the case where the phase constant difference is constant. Hence, a new structure is proposed in which the phase constant difference increases gradually as the waveguide spacing is increased. This structure is analyzed. Unlike the conventional directional coupler, this structure has a large fabrication tolerance as regards the waveguide length in the parallel portion and the coupling coefficient and operation independent of the polarization can be obtained.
Improvement of power efficiency for the class‐BD amplifier with final bridge circuits
Authors: Mochimaru Masayoshi 
Published: July 2007

AbstractThe class‐D amplifier section used in a bridge‐type hybrid class‐BD (BHD) power amplifier is diminished to only one block by use of the full bridge configuration in the final stage. However, since the power loss in the full bridge is larger than that of the half‐bridge used in the original hybrid class‐BD (HD) amplifier, the BHD amplifier cannot overtake the HD amplifier in the power efficiency without selecting for a high load resistance.This paper presents a new method for improving the power efficiency of the BHD amplifier by reduction of the power loss in the final bridge section. In the improved amplifier, the bias voltage applied to the bridge is minimized instantaneously corresponding to the load current. Moreover, the additional emitter resistor of the BJT for prevention of thermal run away is located in the base circuit. A high‐efficiency BHD amplifier with these modifications is developed which has an overall power efficiency of 92 percent at a large output (k = 0.92, output of 48 W) and of 33 percent at a small output (k = 0.1, output of 570 mW) for a load resistor of 8 ω and a distortion factor of less than 0.1 percent.
Study on discharge circuits for word‐lines in high‐speed bipolar rams
Authors: Yamaguchi Kunihiko , Homma Noriyuki , Sakurai Yoshiaki 
Published: July 2007

AbstractTo speed‐up the access of bipolar RAMs, the fall‐time of the word‐line drive voltage must be reduced by the discharge circuit. Various word‐line discharge circuits have been proposed for this purpose. This paper aims at the determination of the best discharge circuit for the future high‐speed, large‐capacity RAM. Four typical conventional kinds of discharge circuits plus one each newly proposed discharge circuit for small and large capacities are applied to the same memory cell array, and the performances are compared by circuit simulation with the same load condition and the same device.As a result, when the degree of integration is not very high and the voltage drop in the word‐line can be ignored, the conventional delayed‐type discharge circuit is the best. When the integration is high and the voltage‐drop in the word‐line cannot be ignored, the newly proposed discharge circuit flowing the discharge current also from the upper word‐line is shown to be the best. Thus, it is concluded that the newly proposed discharge circuit is well‐suited to the future high‐speed, large‐capacity RAMs. The performance of the typical delayed‐type discharge circuit is actually measured for 4‐kbit RAM; and it is verified that the fall‐time of the word‐line drive voltage is reduced, as in the result of simulation. This paper presents a discussion concerning primarily the comparison of performances among the newly proposed and conventional discharge circuits.
Stress analysis of a metal cap with sapphire windows for hybrid ICs
Authors: Fukuoka Yoshitaka , Nishimura Takuya , Terao Takahiro 
Published: July 2007

AbstractTo hermetically seal a hybrid IC with several EPROM IC ships, sapphire windows are brazed to a metal cap. Since it was necessary to investigate the pressure resistance of the sapphire windows, stress analysis was performed using the finite element method. In stress analysis, we consider the thermal stress generated in brazing the sapphire window on the metal cap, the forced stress generated in the hermetic seal process of the hybrid IC and the pressured stress generated in the hybrid IC. The allowable stress in sapphire was measured by the bending test with two‐point support to obtain the stress limit of sapphire. The theoretical and experimental results were compared to confirm the validity of the analytical model.The analytical method developed in this study will be helpful to achieve high reliability in a hybrid IC with sapphire windows.
Some interesting transmission characters of nonradiative dielectric waveguides using high‐permittivity material
Authors: Shinohara Soubee , Yoneyama Tsukasa 
Published: July 2007

AbstractThe nonradiative dielectric waveguide (NRD‐guide) is a dielectric waveguide which normally is composed of low‐permittivity dielectric materials; but, if high‐permittivity materials are used, then the circuit size may be reduced. However, when high‐permittivity materials are used, then single‐mode transmission becomes impossible and some unpredictable phenomena are observed which have never been observed in a low‐permittivity waveguide.In this paper, transmission characteristics of the high‐permittivity nonradiative dielectric waveguide are studied theoretically as well as experimentally. Assuming that the presence of small air gaps between the dielectric strip and metal plates of the NRD‐guide, which cannot be avoided in practice, is the origin of these phenomena, the analysis has been performed which shows that a serious effect occurs even for extremely small gaps and the bandwidth of single‐mode transmission becomes very small. Ultimately, this makes the single‐mode transmission impossible. The electromagnetic field distribution in the NRD‐guide is also calculated and the curious phenomena are interpreted physically. Moreover, a trapped insular NRD‐guide is proposed which permits single‐mode transmission even if high‐permittivity material is used. An experimental confirmation is made of the usefulness of this new type of NRD‐guide.
Some characteristics of Pd electrical contacts mounted on relays that make and break a dc 30‐v, 10‐a resistive circuit
Authors: Kubono Takayoshi 
Published: July 2007

AbstractA description of some of the measured characteristics of palladium switching contacts mounted on miniature relays is presented.For 100,000 switching operations of Pd contacts in the dc 30‐V, 10‐A resistive circuit, we measure the duration of each closing and opening are at each switching, the contact resistance at each closure, the temperature of supporting arm nearby the stationary contact, the number of bouncing at each closure, and the number of switching actions with normal switching functions. Then we compare the data with those data on Ag, AgCdO12 wt% and AgSnO29.3 wt% contacts.On contacts with duty‐making current, closing‐arc duration is very short and the amount of metal transfer is very small. On contacts with duty‐breaking current and those with both making and breaking duty, the large amounts of metal transfer that result will create a large pip and a deep crater on each contact pair.These large pips, deep craters, and the palladium oxide of true contact area influenced greatly each characteristic. Therefore, an obvious difference did not appear between each characteristic in nonpunched contacts and those in punched contacts.After several thousand switching operations, the real contact area consists of a large pip and a crater with a whitish surface; this contact area is made by metal transfer and is made of palladium oxide. It is discussed here that these large oxidized palladium pips and craters influence greatly arc duration, contact resistance, contact sticking, and shortening of the closing‐arc duration simultaneously with an increase in the number of switching operations.
Fabrication of sin thin films by rf biased microwave plasma CVD
Authors: Itoh Naomi , Kato Kiyotaka , Kato Isamu 
Published: July 2007

AbstractThe purpose of this study is to clarify the effect of ion bombardment during the deposition of silicon nitride film. Since silicon nitride is an insulator, ion bombardment was controlled by RF bias to the substrate. When the effective value of the RF voltage was increased from 0 to 120 V, the self‐bias, which is an indicator of the acceleration voltage of ions is impinging on the film, monotonically changed from 0 to −75 V.Therefore, when RF voltage is increased, the ion bombardment increased, hydrogen content in the film decreased, the content of nitrogen and silicon in the film increased, and the film density increased. This phenomenon is caused by the acceleration of surface reaction due to the thermal effect on the film surface by the increase of ion bombardment. The Si/N ratio was constant regardless of the RF voltage.
Three‐dimensional electromagnetic analysis of rectangular waveguide containing high‐permittivity anisotropic dielectric
Authors: Ko Youngho , Yoshida Norinobu , Fukai Ichiro 
Published: July 2007

AbstractVarious waveguides made of different materials with complex configurations have been reported for use at the millimeter‐wave frequencies to optical wavelength. In general, it is difficult to analyze vectorially the characteristics of the waveguide with a three‐dimensional shape.In this paper, the spatial network method using all of the electromagnetic field components is employed as a vector analysis method to analyze a rectangular waveguide loaded with an anisotropic material with an extremely high relative permittivity. As the anisotropic material, the iron‐doped rutile used in a traveling‐wave maser is assumed.First, the propagation constant for the basic mode of the rectangular waveguide loaded completely with an anisotropic material is obtained. Next, the change of the propagation characteristics for the symmetric and non‐symmetric cases is studied for a rectangular waveguide partially loaded with an anisotropic material. The electromagnetic field distributions are presented for the case where the relative permittivity tensor of the anisotropic material has only the diagonal terms and where off‐diagonal terms exist. By means of the time domain analysis, the wave propagation in an anisotropic material can be found successively so that the effects of the boundary shape and the medium condition can be known directly.
Achromatic liquid crystal display using homogeneously oriented nematics with a compensation layer
Authors: Takahashi Taiju , Saito Susumu 
Published: July 2007

AbstractThis paper describes a homogeneously oriented LCD with a homogeneously oriented Np driving layer and a homogeneously oriented Np compensator and its characteristic. In general, in such an LCD, the V‐T characteristic improves as 〈Δn〉10d1 becomes larger. When the elastic constant ratio K33/k11 is small and the dielectric constant ratio is close to unity in the Np material, the V‐T characteristic remains sharp even if 〈Δn〉10d1 is small. Considering both high time‐division driving and low‐voltage driving, vp and n should be chosen so that 〈Δn〉= 〈Δn〉p = 〈Δn〉n does not deteriorate. Using ZLI‐2842 (manufactured by Merck & Co., Inc.), 〈Δn〉 of 7.5 percent was obtained when 〈Δn〉10d1 = 0.76 μm, where the achromaticity was comparable with that in the VAN type. As 〈Δn〉10d1 increased, the viewing angle characteristic became worse. In a cell with 〈Δn〉10d1 suitable for high time‐division driving at a duty cycle lower than 1/200, the viewing characteristic was worse than those in the VAN CSH types. However, in a homogeneously oriented Np LCD, the instability caused by the dynamic scattering effect which is common in the VAN type does not occur.
Analysis of short‐channel effect in thin‐film SOI MOS transistor
Authors: Nakamura Kaori , Okura Yasuyuki , Takeda Eiji , Izawa Ryuiti 
Published: July 2007

AbstractThe short‐channel effect in thin‐film SOI MOS‐FETs was analyzed by two‐dimensional, two‐carrier simulation. In thin‐film SOI MOSFETs, the channel length dependence of the threshold voltage is influenced strongly by the avalanche effect caused by impact ionization. It was found that the short‐channel effect is enhanced by the avalanche effect.The holes generated by impact ionization raises the substrate potential, causing a decrease in the potential barrier between the source and substrate. In bulk MOSFETs, the potential barrier is not affected by the holes generated by the avalanche effect because the holes flow into the substrate electrode. However, in thin‐film SOI MOSFETs, the potential distribution near the source is influenced strongly by the holes because the holes flow into the source. The holes generated by the avalanche effect degrade the punch‐through breakdown voltage. The punch‐through breakdown voltage is highest when the SOI layer has a certain thickness. When the layer thickness is lower than a certain thickness, the punch‐through breakdown voltage decreases. The punch‐through breakdown voltage is lowest when the underlying oxide film is a certain thickness.
A bitmap memory bank which allows block accesses
Authors: Takakubo Hajime , Pham Cong‐Kha , Shono Katsufusa 
Published: July 2007

AbstractAlong with the development of high‐density memory devices (Mbit DRAM), there have been many studies on how to manage two‐dimensional binary data by employing a bitmap method. A special purpose, memory bank for systematically managing bitmap data has been produced. It can be used for various purposes, not only for bitmap CAD but for enumerating binary or gray images expanded on a bitmap editor. In order to transfer bitmap data on the scale of a few Mbits within a practical time, the memory bank executes an access of bitblt method using special purpose hardware for addressing, memory accessing, and bitwise operations. In this study the hardware consists of TTL, PAL, RAM, a custom LSI DRAM controller chip and a custom LSI bit operation chip. The system has a programmable sequencer which makes access from MS‐DOS possible. The memory access rate is 20 Mpixel/s in the case that extended regions are transferred while refreshed and logical operations are being performed.
Quasi‐E junction in a planar circuit
Authors: Takashima Mitsugu , Iga Hiroaki 
Published: July 2007

AbstractIn the E‐junction, when the phase shifts from the E‐arm to two straight arms are in‐phase and out‐of‐phase, respectively, the phase shifts in the opposite directions are also in‐phase and out‐of‐phase. On the other hand, in the quasi‐E junction which is a T‐shaped three‐way junction, when the phase shifts from the vertical arm to the two straight arms are in‐phase and out‐of‐phase, the phase shifts in the opposite direction are out‐of‐phase and in‐phase, respectively.In this paper, the quasi‐E junction characteristics are studied and two circuit configurations and their elements are derived. Next, the relationship between the quasi‐E junction and the E junction is studied. The result found is the symmetry. Also, the two circuit configurations are actually circuit systems. One of them is made of two gyrators (a nonreciprocal circuit in which the phase shift from the left to the right is −π/2 while the one in the opposite direction is π/2) and an H‐plane T junction in which the phase shifts between the vertical arm and each straight arm is −π/2 if the phase shift between the ends of the straight arms is π. From the measured results of the circuit system designed and fabricated, the operating principle of the quasi‐E junction is confirmed.The circuit configuration in this paper contains active devices since active gyrators are used. However, due to the fact that it is a planar circuit, the technology is important for MIC.
An analog neurochip and its applications to multilayered artificial neural networks
Authors: Masumoto Daiki , Ichiki Hiroki , Yoshizawa Hideki , Kato Hideki , Asakawa Kazuo 
Published: July 2007

AbstractA multipurpose neurochip (analog neuroprocessor) has been developed that incorporates neural networks into equipment. This paper describes this analog neurochip and the multilayered artificial neural networks that run on it. This chip was built using 2‐μm Bi‐CMOS technology. Input/output signals are analog and weights are digital. An analog time‐sharing bus is used for input and output; analog data can be sampled at intervals of 13 μ. An example of the exclusive‐OR problem has been included. Construction of a three‐layered network using the chips required development of a system that consists of the following:

chip
memory to store weights
board on which chips, memories, and control circuit are mounted
software simulator dedicated to error backprop‐agation learning
This system performs parallel processing in each network layer and executes pipeline processing between the layers. It has a processing speed of up to 0.6 million interconnections per second (MIPS). The current chip has some problems, including dispersion of device characteristics, loss of significant digits of weight, and digit overflow. Some countermeasures for these problems also are examined.
Optical phase‐locked loop for suppression of external disturbances in optical fiber sensors
Authors: Hirose Yasuo , Tsuzuki Yasuo , Ando Haruo 
Published: July 2007

AbstractVery high sensitivities can easily be achieved in optical fiber interference‐type sensors which are also sensitive to such external disturbances as low‐frequency phase changes of interference‐light, oscillations getting into the optical system in the form of frequency fluctuations, etc. To realize stable measurements, it is very important to suppress these effects.This paper investigates the second‐order optical phase‐locked loop (OPLL) developed to suppress such fluctuations due to external disturbances and treats an optical vibration sensor as an example. By introducing small‐amplitude phase variations into the interfering lights, a new detection method is adopted to investigate the effects of external disturbances. It can suitably be applied to fiber‐transmission type sensors to which it was difficult to apply the previous differential detection methods for the purpose of compensating external disturbances. The OPLL remains locked in at about 50‐Hz frequency pulling range and can suppress frequency and phase variations caused by external disturbances having frequency components of at most 10 Hz.