bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of low‐noise inductance with high‐Q
Authors: Nakamura Masataka , Okine Mitsuo , Shigehiro Takanori , Ishizaki Tatsuya 
Published: July 2007

AbstractA number of methods have been proposed for LC simulation due to its inherent low sensitivity as a doubly terminated lossless reactance circuit [1 ‐ 8]. A direct simulation of L is effective since it has a one‐to‐one correspondence with the circuit parameters and is applicable to cases other than filters. The method is advantageous over the passive inductance since the active device such as a transistor or an operational amplifier can simulate an inductance with a large L value and a high Q. However, the noise is larger than that in a passive structure and hence reduction of noise is an important subject. This paper proposes a circuit which realizes a simulated low‐noise and high‐Q inductance with one transistor and one operational amplifier. In noise analysis, a low‐noise design is presented with the introduction of the noise factor. Further, the effect of imperfection of the active device on the L and Q values, and the signal level in the circuit are discussed in detail.
An analysis of scattered near field and induced current of a beam wave by pits on optical disk using boundary element method
Authors: Manabe Katsuya , Miyazaki Yasumitsu , Tanaka Takaaki 
Published: July 2007

AbstractNumerical analysis of the scattering of a beam wave caused by pits which are assumed to be absolute conductors is carried out in order to obtain the optimum shape of pits and pregrooves and achieve high density on an optical disk. For analysis, the boundary element method (BEM) is used because it is adaptable to any shape of pits and pregrooves and any type of incident beam. For rectangular or trapezoidal concave and convex pits, scattered fields and induced currents are calculated as functions of the angle of the pit wall and track pitch, and comparison between the two is made. In the case of convex pits, it is found that the minimum track pitch without crosstalk for E‐wave and H‐wave are 2w and 1.8w (w: the spot size of the incident beam), respectively. As the pit shape is changed from rectangular to trapezoidal, the intensity change of the main lobe with or without the pit is small. Finally, the current density on the disk, which is induced by scattering, is calculated.
Electroluminescence from anodized tantalum pentoxide thin films
Authors: Miyairi Keiichi , Hanawa Ikuo 
Published: July 2007

AbstractTo understand the electric breakdown characteristic of anodized tantalum pentoxide (Ta2O5) films, the electroluminescence phenomenon was investigated in the electric field ranging from low field to the breakdown field. Since the luminescence is weak, it was detected by using a photomultiplier tube and a lock‐in amplifier.The luminescence was independent of temperature but was strongly dependent on the applied voltage. When the electric field was slightly lower than the breakdown field, the luminescence due to the carrier injection based on the Schottky effect was observed. When the electric field was close to the breakdown voltage, luminescence due to the electron avalanche was observed, where the luminescent spectrum had a peak at 600 nm.These observations indicated that the electric breakdown is related to the electron avalanche.
A continuously calibrating charge redistribution A/D converter
Authors: Nakano Motohiro , Tsukamoto Kousuke , Miyata Takeo , Saitoh Takayoshi 
Published: July 2007

AbstractThis paper describes a self‐calibrating A/D converter (ADC), which continuously obtains calibration data for the error of circuit elements and carries out self‐calibration using these data in A/D conversion. This ADC is able to maintain a highly accurate conversion for a long time by renewing the calibration data continuously. By subdividing the calibrating operation and distributing the operation among the conversions, a lowering of conversion speed which is due to the calibrating operation can be reduced. On the assumption that the calibration data are destroyed or circuit parameters are varied by drift, conventional self‐calibrating ADC and this ADC are simulated and experiments are carried out by breadboard circuit. Consequently, it is verified that the conventional self‐calibrating ADC is not capable of maintaining highly accurate conversion for data destruction and drift. On the other hand, the continuously self‐calibrating ADC is able to recover the conversions, accuracy after several tens conversion cycles for data destruction and maintain highly accurate conversion against variation of circuit parameters due to drift.
Merged bipolar transistor models including the substrate current
Authors: Inohira Susumu , Shinmi Toshio , Higuchi Hisayuki , Iida Kyoichi , Ohkawara Hiroshi 
Published: July 2007

AbstractHigh integration density and high‐speed operation are obtainable by miniaturization of bipolar LSI devices. In modern bipolar integrated transistors, an undesired current flows into the substrate due to the parasitic sub‐PNP transistor. For example, for Bi‐CMOS circuits, this substrate current can be the main cause of reduction in the supply voltage.This paper proposes merged models for the NPN and lateral PNP transistors which include the substrate current due to the parasitic sub‐PNP transistor. The extraction of model parameters for the calculation of substrate current is also described. By the application of these models to the simulation of NPN transistor for Bi‐CMOS memory and lateral PNP transistor of linear process, good accuracy of dc saturation and substrate current characteristics can be obtained. Its application to the simulation of decoder/memory cell of Bi‐CMOS memory is demonstrated.
New air‐gap‐type piezoelectric resonator supported by thin films from the surface
Authors: Yamanouchi Kazuhiko , Oba Masaki 
Published: July 2007

AbstractIn a piezoelectric resonator supported by a thin film with an air gap between the substrate and the resonator, it is difficult to construct a resonator because of the stress in the resonator. Stress also affects the electrical properties in this device. In this study, stress is minimized by using (1) a structure supported at one end, and (2) a surface‐supported structure. Piezoelectric resonators supported by a thin film with an easily constructed structure were proposed. In device (1), the resonant frequency, the quality factor Q and the capacitance ratio γ were 300 MHz, 1200 and 54, respectively. In device (2), the resonant frequency, Q and γ were 1.77 GHz, 300 and 250, respectively. Breakage of the thin film with a small air gap and stress in the film will be discussed. Finally, the usefulness of this method will be proved.
A 256‐K 13‐nanosecond CMOS SRAM
Authors: Asahina Katsushi , Murakami Shuji , Ichinose Katsuki , Minami Fuyumi , Funakoshi Yasuhiro 
Published: July 2007

AbstractRecently, many types of very high‐speed static RAMs (SRAM) using CMOS or BiCMOS technologies have been announced. Even with CMOS SRAMs, which operate in the range of 10 ns access time, both device and circuit technologies and also usage and reliability problems become prominent, and must be solved in order to achieve adequate speed performance.This paper discusses technical problems and their realistic solutions for achieving very‐high speed SRAMs using CMOS from the viewpoint of device and circuit technologies. Consequently, short channel MOSFETs using 1.0 μm NMOS and 1.0 μm PMOS gate lengths were used to reduce the access time. In order to reduce the soft‐errors that cause problems when high‐speed SRAMs are operated with a short cycle time, theVthof memory cell transistors is set higher than the level in the other circuits. Hence, the soft‐error rate is the same when the device is operated with a longer cycle time.With respect to circuit technology, a high sensitivity sense amplifier is used with a smaller gain decrease under low voltage, a circumstance which is suitable to high‐speed SRAMs that are sensitive to supply voltage bounce due to electrical noise within the chip.In order to implement systems using high‐speed SRAMs, a write‐timing control circuit is introduced, which alleviates the timing constraints on the address skew during write timing. Utilizing these technologies with a CMOS process, a 256‐K SRAM with an access time of 13 ns has been achieved.
Device and interconnect structures suitable for ultrahigh‐speed LSIs
Authors: Ohmi Tadahiro , Imai Shigeru , Hashimoto Takashi 
Published: July 2007

AbstractFor realization of ultrahigh‐speed LSIs, devices with large current driving capabilities and interconnects with small parasitic resistances and small parasitic capacitances are desired. When a high‐speed signal propagates along the conventional metal‐insulator semiconductor (MIS) interconnect, the signal is subject to waveform distortion due to the power consumption by the current induced in an Si substrate. On the other hand, an interconnect‐ground capacitance with a certain magnitude is required for suppression of cross talk. For these reasons, an interconnect of the metal‐oxide‐metal structure is proposed.Next, in regard to devices, it is considered that the MOS transistor is an induced charge control device and hence the speed increase can be accomplished with superposition of the potential control function of the bipolar transistor. This objective is accomplished in the current overshoot transistor in which the floating potential of the channel formation region of the SOIMOSFET is used intentionally. If the base width of the bipolar transistor is made extremely small, the carrier velocity is saturated so that the current value becomes independent of the base width. In addition, the difference between the uniform base and the graded base disappears. In the ultra‐high‐speed LSIs, the load to the interconnect increases due to the cross‐talk suppression. Therefore, the importance of these devices with large current driving capabilities becomes even more significant.
Measuring the opening arc duration between the punched and/or nonpunched contacts
Authors: Kubono Takayoshi 
Published: July 2007

AbstractSince 1984, various kinds of experimental data on the punched contacts were gathered to confirm their efficacy. In this paper, the duration data of the opening arc which causes the damage of relay contacts are collected and investigated in every production lot of specimens.The production lot number in all specimens is seven. The specimen contacts are four kinds of external forms and mounted on three kinds of relays which differ in the driving mechanism for movable contact.AgCd012 wt% contacts are mounted on three kinds of relays. Also, AgCd012 wt%, Ag and AgSnO29.3 wt% contact pairs are mounted on one kind of relay.In the 1985 and 1986 production lot, a few specimens showed a wide scatter of data under the same experimental conditions. Even though specimens were made by three companies and differed from production lots in the same company, all specimens show that the opening arc duration between the punched contacts becomes long together with the increase of switching operations. Also, the opening arc duration is nearly equal to that of the nonpunched contacts in experiments over a five‐year period.
Analysis of rotationally symmetric resonators by the finite element method
Authors: Matsuhara Masanori , Goto Seiji 
Published: July 2007

AbstractThis paper proposes an analysis method based on the finite‐element method that can be applied to such rotationally symmetric structures as circular cylindrical resonators.In general, the main drawback associated with the finite‐element methods for electromagnetic eigenvalue problems is the mixing of the nonphysical or spurious solutions with the physical solutions. However, in the method proposed in this paper, all the spurious solutions have zero eigenvalues and can easily be separated from the physical solutions, thereby eliminating the problem of spurious solutions. Moreover, the computation can be treated as two‐dimensional, thus a large saving in computer time and storage is obtained compared to three‐dimensional computations.Theoretical equations are derived and by using a numerical example the rightness of this method is demonstrated.
Evaluation of ion‐implanted silicon substrate by photothermal deflection spectroscopy
Authors: Horita Susumu , Miyagoshi Eiji , Yago Ken'Ichi , Hata Tomonobu 
Published: July 2007

AbstractIt is important to evaluate the crystalline quality of an ion‐implanted layer after annealing. The evaluation method must be simple and nondestructive. In this study, a silicon substrate was implanted with various doses of P+ of Si+ at various acceleration energies and the crystalline quality of the implanted layer after annealing was evaluated by photothermal deflection spectroscopy (PDS). The results were compared with those obtained by cross‐sectional TEM observation, RBS, resistivity and ESR measurements.Hence it was found that the PDS method can evaluate the amorphous layer thickness formed by ion implantation and the quality of crystalline defects as a change of additional absorption. The PDS method can detect microcrystalline defects and changes in crystalline structure due to annealing which are not observed by the RBS and resistivity measurements. Because the PDS method is relatively simple and nondestructive, it is effective in evaluating the crystalline quality of an implanted layer.
Approximate analysis of dielectric gratings with multiple reflection by boundary
Authors: Mori Shizuo , Teraguchi Hirofumi , Yamakita Jiro , Rokushima Katsu 
Published: July 2007

AbstractApproximate two‐wave analysis of planar dielectric gratings with boundary reflection is presented. The analysis is derived from previous rigorous theory [2] by neglecting the higher‐order waves and the second derivatives of the field amplitudes but taking into account the effect of boundary reflection. The pulsation phenomena of the diffraction efficiency due to the multiple reflection usually ignored in most of the approximate analysis can be given clearly by simple 2 × 2 matrix calculations for practical gratings of small index‐modulation type. The analysis can be applied not only to isotropic but also to anisotropic gratings so long as incident waves and only one diffracted wave play a dominant role. Numerical results are given and are compared with rigorous results.
A 72 k CMOS track–free gate array with embedded 1 Mbit DRAM
Authors: Sawada Kazuhiro , Iizuka Tetsuya , Uchino Yukinori , Kobayashi Teruo 
Published: July 2007

AbstractA 72 k CMOS track‐free gate array with embedded 1‐Mbit DRAM has been fabricated using 1.0 μm HC2MOS twin‐well process technology. This is considered to be one of the solutions for the applications of audio/visual signal processing that require high‐density memories of megabit class on a chip.Based on the evaluation and discussion of the fabricated test devices, this paper reports the possibility of logic LSI's with embedded DRAM that has been assumed difficult. As for the design of the DRAM part, several kinds of optimized design were introduced considering the process compatibility and noise immunity against the gate array. For example, the substrate bias‐free design, the virtual/pseudo SRAM mode and the cell within the isolated P well were considered.The high noise immunity in the real usage is confirmed by the evaluation utilizing the emulated noise generator circuit fabricated by the evaluation utilizing the emulated noise generator circuit fabricated in the gate array part. The delay time in the gate array is 0.4 ns and the worst case access time in the DRAM is 60 ns.
An architecture of real‐time video signal processing LSI‐picot
Authors: Yagi Nobuyuki , Yajima Ryoichi , Enami Kazumasa , Mikami Shigemi , Sasaki Nobuyuki , Hoshino Kouji , Harukawa Kazuhiro , Yamada Hideki 
Published: July 2007

AbstractA real‐time video signal processing LSI‐Picot has been developed which processes dynamic images at video rate. Picot has an architecture which is suited to the image and video signal processing. By employing several internal buses and a new program control scheme, all operations are performed in one cycle 70 ns (=1/14.3 MHz). It has functions of not only addition, subtraction, and multiplication but also the maximum, minimum and absolute value operations, which are indispensable to image processing. Its dedicated addressing units can concurrently perform the memory write/read and operation with a data memory of up to 16 Mw connected, and it can cope with a large‐size static image exceeding that of HDTV. Picot is constructed using 1.5 μm CMOS gate array technology and a 30,000‐gate circuit integrated on a 14.95 mm × 14.95 mm chip, to be implemented on a 223‐pin PGA. It operates on a 5‐V single power supply with the power consumption of approximately 1 W.
4 Gbit/s optical receiver IC's using high‐speed bipolar process “ESPER”
Authors: Deguchi Tatsuya , Tahara Akinori , Takada Tadakazu , Hamano Hiroshi 
Published: July 2007

AbstractA high‐speed silicon bipolar process (ESPER) is developed using the two‐level poly Si process. The ESPER transistor reduces the collector‐base capacitance by extending the poly Si base electrode onto a thick oxide film. In addition, the base resistance is reduced by forming the poly Si extended base electrode and emitter with the self‐aligned structure. An optical receiver IC was fabricated using the combination of the ESPER transistor and the trench isolation structure. The preamplifier and the decision circuit of the optical receiver IC have been evaluated. The preamplifier frequency bandwidth of 3.6 GHz was confirmed and the decision sensitivity of 90 mV at 4 Gbit/s.
Optical transfer properties of two‐photon‐pumped image upconverter–in the case of gaussian beam pumping
Authors: Okamoto Atsushi , Mishima Teruhito , Sakuraba Ichiro 
Published: July 2007

AbstractSpatial frequency transfer properties are analyzed for the parametric image upconverter using Gaussian beam pumping. First, the Fourier spectra of the pumping Gaussian beams on the interaction plane are derived by taking account of lateral shifts of the beams and the incident spatial frequency with respect to the upconversion system. The spatial‐frequency transfer equation for thin nonlinear medium is applied to this Gaussian beam system so that the Fourier spectrum of the sum frequency optical response is derived for an infrared plane‐wave input. Specifically, it is shown that the phase matching property of the image upconverter is dependent not only on the directions of the pumping beams but also on the geometric relationship between the two beams, the spot sizes and the radii of curvatures at the interaction plane.Second, the optical field distributions of the sum frequency response for the unit‐impulse infrared input is derived. From this, the relationship between the overlap of the two pumping beams and the conversion efficiency of the system is derived. Also, the imaging equations of the Gaussian beam pumping system are derived and compared with those available for the plane wave pumping and the point source pumping so that generality of the present imaging equations is confirmed.
Inverse analysis of refractive index profile of optical waveguide from propagation‐mode near field pattern including noise
Authors: Sawa Shinnosuke , Ono Kazuo , Takahashi Seiichiroo 
Published: July 2007

AbstractTo estimate the transverse refractive index distribution of optical waveguides, comparison of the measured light intensity and that calculated from the assumed refractive index distribution is proposed as a new method.The assumed refractive index distribution is corrected to give the best agreement between the two intensity distributions [5, 6]. This is the reverse procedure of the previous method in which the refractive index distribution is extracted directly from the field intensity distribution [1–4] and, therefore, the present method can be called the “inverse analytical method”.In this paper, simulated numerical investigations of the inverse analytical method are carried out when the intensity distributions are noise proofed. The true step and graded refractive index distributions of buried and diffused types are assumed and Gaussian noises with two standard deviations are added to their corresponding light intensity distributions.Then the present method is applied to assess their refractive index distributions. Numerical simulations of the previous differential method [2] also are carried out for buried‐type graded refractive index distribution. As the result of comparison, it is shown that the results do not depend on the smoothing process of the intensity distributions as they do in the case of the differential method. Therefore, it is quite possible to assess the refractive index distribution even without any smoothing process.
Electromagnetic field analysis of waveguide‐microstrip line transition by spatial network method
Authors: Tajima Tatsuhiko , Koike Shoichi , Okubo Naofumi , Kawasaki Yoshihiro 
Published: July 2007

AbstractThe waveguide to microstrip line transition has been used widely in the microwave and millimeter wave bands for several radio communication systems. Since transition from solid waveguide to planar microstrip line is involved, the internal field distribution becomes complicated. Moreover, different types are required for different applications, thus the analysis of the transition is generally very difficult.The design of the transition till now has been based purely on the trial‐and‐error method. For such complex structures, the best way to find the characteristics is via computer simulation.In this paper, the spatial network method, which is excellent for three‐dimensional (3‐D) transient analysis, is applied to the transition and the possibility of unified simulation of the overall structure is demonstrated. The model of transition used for this analysis is such that microstrip line is inserted perpendicularly to the window as well as to the H‐plane of the waveguide working in the TE10mode.As a result of analysis, the dependence of frequency characteristics on various parameters of the transition shape and its relationship with the complex internal electromagnetic field is clarified. In particular, with the help of simulation of the Poynting power flow, the propagation conditions from the waveguide to microstrip line could be shown successively on the time axis. Thus, we have shown that the simulation based on this method can be used for efficient transition design.The authors wish to thank Mr. Shiomi, Communication Research Lab., of Postal Department, Mr. Kurihara, Fujitsu Research Lab., and Mr. Noguchi, Fujitsu Tohoku Digital Technology, Ltd., for their helpful guidance. Thanks are due also to Associate Prof. N. Yoshida of Hokkaido University for important discussions.