bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new algorithm for transient analysis of electromagnetic wave systems
Authors: Kuroiwa Takashi , Hosono Toshio 
Published: July 2007

AbstractIn the analysis of a general linear system including the electromagnetic wave transmission systems, it is often necessary to derive system functions such as the immittance function and the transfer function from the frequency characteristics. In solving these problems, it is possible to use the Herglotz‐Cauer theorem for the immittance function and Hosono's theorem for the transfer function. In these theorems, it is necessary to calculate integrals on the frequency when the system function is derived. There are a limited number of cases that can be solved analytically. However, when Hosono's theorem is combined with the fast inversion of Laplace transform (FILT), it is predicted that such a combination is a powerful tool for analyzing the transient phenomena of the electromagnetic wave propagating in plasma, waveguides, and optical fibers. To confirm such a prediction, the transient phenomena of the electromagnetic wave propagating in a plasma were analyzed as an example so that the effectiveness was supported.
Fast ROM macrocells for ASICs
Authors: Shibata Nobutaro 
Published: July 2007

AbstractSRAMs and ROMs are installed on high‐performance ASICs as the memory macrocells. This paper discusses the design of mask ROMs as the macrocells from the viewpoint of the high‐speed and low‐power dissipation. NOR‐type memory cell array configuration is adopted, and the memory content is set using the LSI mask for contact process. A memory cell programming method is proposed where the source of the MOS transistor and the GND line are connected or disconnected according to the memory content. In this method, the adjacent colls can share the contact area to a bit‐line. This helps to reduce the p‐n junction capacitance, which dominates the parasitic capacitance of the bit‐line, to be halved. Using a reference voltage generator, the bit‐line is controlled close to GND level, which improves the detection sensitivity of the current‐mirror sense amplifiers. The small‐amplitude operation of the bit‐lines is realized and the access time is reduced. As a technique to reduce the power dissipation, the virtual GND lines are introduced, which are controlled by the column address signals. The lines are controlled to the floating state in the stand‐by mode so that the dynamic power dissipation is reduced. A test chip was designed and fabricated by a 0.5‐μm CMOS process, and the address access time of 7.2 ns was obtained for the 4‐K word × 4‐bit organization.
Circularly polarized absolute‐value rays in stratified absorbing media
Authors: Tokumaru Shinobu 
Published: July 2007

AbstractTo provide an example of circularly polarized absolute‐value rays in a nondispersive absorbing medium, the theory of ray tracing is presented in the case in which a plane wave is incident on a planar layered medium. Specific tracing methods are presented for the loci of the real phase plane normal, the loci of the projection ray related to the flow line of the normalized Poynting flux, the loci of the circularly polarized absolute‐value rays, and the intensities of these rays. The relationships to Poynting flux and their tracing method are described. Further, in the planar layered medium, an anisotropic projection ray index of refraction is introduced to the projection ray. It is shown that Fermat's principle holds under this index of refraction. On the other hand, Fermat's principle also holds in the tracing of the trajectory of the real‐phase plane normal. In Fermat's principle of the projection ray, its relationship to the energy flux density is new.
A magnetostatic wave radiation impedance of symmetric slot line in signal‐to‐noise enhancer
Authors: Asao Hideki , Miyazaki Moriyasu , Oh‐Hashi Hideyuki , Ishida Osami 
Published: July 2007

AbstractIn a slot‐line‐type signal‐to‐noise enhancer for a magnetostatic wave, it is shown theoretically and confirmed experimentally that enhancement can be improved by the symmetric slot‐line structure with yttrium iron garnet (YIG) films on both sides of the slot line and by the layered structure of high permittivity materials. It is shown that the improvement in the amount of enhancement requires an increased attenuation constant of the slot line caused by the conversion loss of the linear operation to the magnetostatic wave. The magnetostatic wave radiation impedance is then derived by recognizing the contribution of the magnetic flux density normal to the slot plane among the electromagnetic field components traveling along the slot line to the conversion of the magnetostatic wave. By means of this radiation impedance, the attenuation constant is derived for the symmetric slot line and the slot line with a high permittivity layered structure so that improvement to enhancement is clarified.
Analysis and experiment on phase‐conjugate reflectivity of CAT mirror
Authors: Yamada Hiroshi , Okamoto Atsushi , Enbutsu Koji , Mishima Teruhito , Sato Kunihiro , Sakuraba Ichiro 
Published: July 2007

AbstractThe effects that the arrangement of light rays inside the photorefractive crystals have on the reflectivity of CAT mirrors are analyzed anew. Experiments are performed using BaTiO3 crystal and the measured results are compared with those of numerical calculations.First, for generation of beam fanning in photo‐refractive crystals, three different cases of generation are considered, i.e., at the plane of incidence of the crystal, in the range of maximum coupling coefficient, and in the range of maximum coupling strength. Next, the light‐ray incident conditions (incident position, incident angle, and beam radius) and the generating position of beam‐fanning associated with variations of light‐ray arrangement inside the photorefractive crystal are simulated. In each of these three cases, the phase‐conjugate reflectivity is estimated via numerical calculations from which the effects that light‐ray arrangement have on reflectivity is clarified.Finally, experiments are carried out using a BaTiO3 crystal and the measured data are compared with the simulated results. It is shown that if the angle of the incident beam with respect to the crystal is large, beam‐fanning is generated at the position where the coupling coefficient is at its maximum. When the angle of incidence is small and in the range of small values of the position of incidence, beam‐fanning occurs in the plane of incidence of the crystal. Using this analysis, the light‐ray arrangement required in achieving high phase‐conjugate reflectivity is clarified.
Effects of specimen shape on the measurement of the electromechanical coupling coefficient in inclined electrodes
Authors: Adachi Yutaka , Takenaka Tadashi 
Published: July 2007

AbstractThe electromechanical coupling coefficient k can be determined by measuring the frequency characteristics of admittance. However, it is known that the specimen shape affects the measurement of the admittance frequency characteristics. In this paper, the finite element method was employed to investigate the effects of sample electrode inclination on the electromechanical coupling coefficients. The results indicate that the electromechanical coupling coefficients for the stretching vibration mode (31) of a rectangle, the stretching vibration mode (33) of a bar, and the expansion vibration mode (p) of a disk decrease when the sample electrodes are inclined. No spurious vibration was observed in the transverse vibration of (31) and (p) modes when the sample electrodes were inclined. However, a spurious vibration was observed in the longitudinal vibration of the (33) mode. These observations were confirmed by experiment.
Ultrasonic motor based on coupled longitudinal‐bending vibrations of a diagonally symmetric piezoelectric ceramic plate
Authors: Aoyagi Manabu , Tomikawa Yoshiro 
Published: July 2007

AbstractThis paper discusses the operating principle and performance characteristics of an ultrasonic motor based on the coupled longitudinal‐bending vibrations of a diagonally symmetric piezoelectric ceramic plate. It is well known that longitudinal and bending vibrations couple with each other in a diagonally symmetric piezoelectric ceramic plate.The objective of this investigation is to design a simple and thin ultrasonic motor based on these coupled mode vibrations. The design of a stator for an ultrasonic motor was optimized with respect to vibration mode, capacitance ratio, and direction of vibratory displacement by employing the finite element method. A simple ultrasonic motor was built and its performance was tested. The results indicate that its load characteristics vary widely depending on the contact point of the rotor and the geometry of a piezoelectric plate. Furthermore, attempts were made to equalize load characteristics for bidirectional operations. The efforts revealed that it is possible to equalize the rotation rate, but it is difficult to equalize efficiencies for bidirectional operations. By incorporating a self‐oscillation circuit with an inverter, it is possible to run the motor bidirectionally in a single‐phase mode.
New microscope for measuring the distribution of nonlinear dielectric properties
Authors: Cho Yasuo , Kirihara Akio , Saeki Takahiro 
Published: July 2007

AbstractThis paper describes a new technique for imaging the distribution of nonlinear dielectric constants of ferroelectric materials. This technique is based on the principle that the nonlinear (third‐order) dielectric constants (third‐rank tensor) are very sensitive to the state of the spontaneous polarization and the quality of the crystallization of materials, while the linear (second‐order) dielectric constants (second‐rank tensor) are insensitive to them. Applying this principle, a new microscope for measuring the distribution of nonlinear dielectric properties is developed. This new microscope is used to observe the distribution of the polarization of ferroelectric materials such as lead zirconate titanate (PZT) ceramic and piezoelectric polymer.
Transmission loss of thick‐film conductor lines at microwave frequency
Authors: Ogawa Toshio , Kamimura Noritaka 
Published: July 2007

AbstractIn the hybrid integrated circuit systems which process the RF signal for communications, the transmission loss tends to increase as the frequency is increased, which is a significant problem in the circuit design. The authors have considered thick‐film conductors as conductor materials for the circuit because the thick film is of relatively low cost and can be mass produced. The transmission loss of the RF signal in such a circuit was evaluated experimentally up to 20 GHz.It was found that high‐purity alumina (99.5 percent) is suitable as ceramic substrate material, the transmission loss is too large to be practical in the Ag/Pd conductor system and the transmission losses are not very different and are in the practical range for Au, Ag, Ag/Pt, and Cu conductors. Contrary to the general belief, it was found that the transmission loss can be reduced if the surface of the ceramic substrate is made rough. In order to find the reason, the fine structures of the cross section of the thick‐film conductor was investigated.
Effect of switching interval on some characteristics of relay contacts
Authors: Kubono Takayoshi , Mogami Masahiko 
Published: July 2007

AbstractA normal, open electrical contact pair, mounted in a small relay, was used to make and break repeatedly a dc, 30V/3 Ω resistive circuit up to 100 thousand times; and the relationship between data for each switching and switching interval are analyzed in this paper. Four kinds of switching intervals are set by changing the frequency of applying the rated voltage to drive the electromagnetic coil.No special relationship was found between four different switching operation intervals and data for bounce number at make, arc duration at make/break, and contact resistance at 500 ms after the 10‐A current began to flow.On the other hand, the following points became clear through the experiments.— Temperature at the backside of contacts at 500 ms after the 10‐A current began to flow changes drastically by the difference of the switching interval.— Temperature rise changed linearly and was proportional to the contact resistance at each switching interval.— The more frequent the switching interval, the larger the proportional coefficient.By these results of experiments, the following facts were concluded.— Temperature of electric contact increases with Joule heating of contact resistance and the resistance of the conductor including supporting arms.— The shorter the period of the separated contacts, the larger the temperature difference between measuring point and room temperature became.
Nanohenry inductance measurement using a low parasitic‐inductance probe
Authors: Shimizu Hiroya , Nagata Tatsuya , Nakamura Atsushi 
Published: July 2007

AbstractThe increased speeds of logic circuitry make the electrical characteristics of LSI packages more important. This is especially true of inductance, which is the main source of simultaneous switching noise (SSN). To improve the accuracy of SSN simulations, inductance models of LSI packages should be represented by inductance matrices; and, thus, to construct precise models, it is necessary to have an inductance measurement method.A new inductance measurement method of nanohenry‐order accuracy is proposed that uses an LCR‐meter. Since the parasitic inductance of measurement probes usually decreases accuracy, a special probe with minimized parasitic inductance was developed.The new measurement method has the additional advantage of high spatial resolution. The results of measurements proved to be in good agreement with calculations.
Elastic wave energy‐trapping and its application to piezoelectric devices
Authors: Nakamura Kiyoshi 
Published: July 2007

AbstractIf it is possible to trap elastic wave energy in a localized region of an elastic solid, it is possible to support the solid at a location where no vibration occurs. This enables highly reliable, low‐loss piezoelectric devices to be developed. In this paper various energy‐trapping elastic wave phenomena and vibration are discussed and their applications to various piezoelectric devices such as strip resonators, monolithic filters, piezoelectric transformers, vibratory gyroscopes and SAW devices are described.
Enzyme biosensor based on surface acoustic wave device
Authors: Kondoh Jun , Imayama Teruo , Matsui Yoshikazu , Shiokawa Showko 
Published: July 2007

AbstractIn a shear horizontal surface acoustic wave (SH‐SAW) propagating through a piezoelectric crystal, shear wave and piezoelectric potential due to piezoelectric effect are combined. SH‐SAW can be useful for chemical sensing in the liquid phase. When the load liquid and propagation surface are in contact, the change in the electrical property of the liquid can be detected due to the acoustoelectric interaction. This paper describes a new type of acoustoelectric biosensor with an enzyme membrane on the SH‐SAW propagating plane for detecting pH change in liquid and reports that the SH‐SAW enzyme sensor with urease is highly sensitive in detecting urea. In addition, this paper describes the detection limit, aging characteristic, and high sensitivity of the detector.
Pyroelectric infrared sensor using PZT thin plate on diaphragm as sensitive elements
Authors: Taniguchi Yoshiharu , Murakami Kensuke , Kobayashi Hiroshi , Tanaka Shosaku 
Published: July 2007

AbstractTo improve performance characteristics of a pyro‐electric infrared sensor, especially voltage responsivity (Rv), noise equivalent power (NEP), and response speed, it is necessary to reduce the heat capacity of an infrared sensing element which is made of Pb(Zr, Ti)O3 (PZT) ceramics. A new design for a sensor whose sensing element is made of a thin bulk PZT ceramic plate mounted on a diaphragm fabricated by the Si micromachining method has been proposed and its prototypes have been tested.The prototype sensor has a PZT ceramic plate which is about 10‐μm thick and has a sensing area of 1 × 2 mm2. The new sensor has an Rv value of 36.3 to 37.9 mV/μW which is about five times higher than a pyroelectric sensor with a 100‐μm thick PZT bulk ceramic plate. The amount of sensor noise was expected to be reduced by half. However, the amount of sensor noise increased by a factor of two. Because of the increase in the sensor noise, the values of NEP were 1.8 to 3.3 × 10−2 μW, which is a factor of two to three smaller than the NEP value of the bulk sensor. Furthermore, the rise time decreased to 31 to 35 ms, which is 10 to 20 percent shorter than that of the bulk sensor. Thus, the reduction of sensor noise will be an important challenge for the future.
Application of screen‐printed rare earth oxide protective film to alternating‐current plasma display panels
Authors: Koiwa Ichiro , Kanehara Takao , Mita Juro 
Published: July 2007

AbstractScreen‐printed protective film of rare earth oxides (La2O3, Gd2O3, Dy2O3, Y2O3, and Yb2O3) was applied to ac‐plasma display panels. Screen‐printed rare earth protective films have higher luminous efficiencies than a sputtered MgO protective film. However, it is difficult to obtain a low firing voltage (Vf) from screen‐printed rare earth oxide protective films.Only the La2O3 protective film has a lower firing voltage than the sputtered MgO protective film. Gd2O3 has the lowest sustaining voltage (VS) which is 54 V lower than that of the sputtered MgO protective film. Since rare earth oxide powders with high crystallinity exhibit superior discharge characteristics, it is necessary to improve the crystallinity of the powders. In order to obtain a high luminous efficiency, it is necessary to have a low discharge current. Both Y2O3 and La2O3 have a high current‐limiting effect. The current‐limiting effect is related closely to cell resistance. Since Dy2O3 has a low cell resistance, its current‐limiting effect is low. Gd2O3 has the highest luminance per unit discharge current. If it is possible to reduce the discharge current of Gd2O3 further, it is possible to obtain a higher luminous efficiency. Every screen‐printed rare earth oxide film has an excellent protective effect. However, from the viewpoint of low discharge voltage and high luminous efficiency, La2O3 and Gd2O3 are superior to all other rare earth oxides due to their low discharge voltage and high luminous efficiency.
Reliability of tape automated bonding using Au‐Sn alloy
Authors: Shibata Susumu , Kimura Masaru 
Published: July 2007

AbstractThis paper describes the relationship between the tape automated bonding (TAB) condition and reliability.When too much bonding pressure is applied in inner lead bonding, the bonding characteristic of a finger in contact with a bonding tool edge tends to degrade. When bonding pressure exceeds 21.0 kg/mm2, the finger penetrates a bump, causing damage in the Al pad. The size of the finger is much larger than that of the solder bump. However, if the bonding condition is appropriate, the bonded section is reliable. Adhesive thermal resistance for securing Cu fingers on the TAB tape determines the upper limit of inner lead‐bonding temperature. The alloy is formed during bonding operation. The alloy formation is not sufficient at 380°C, but it is sufficient at 500°C. In outer lead bonding, bonding pressure should be controlled to prevent the substrate surface from cracking. Increasing pad length and width and reducing the temperature difference between the bonding tool and test piece were effective in preventing cracks. In both inner lead and outer lead bonding, the damage of fingers, separation of the bump from the pad, and substrate surface cracking must be taken into account in addition to the properties of the bonded area.
Head‐positioning control system for small‐sized hard disk drives
Authors: Yamada Takehito , Takakura Shinji 
Published: July 2007

AbstractHigh track density has been achieved by adopting an H∞ controller with a feed‐forward compensator using adaptive filter theory in a sector servo system. In applying the H∞ control theory, a state‐space model of an augmented plant was constructed considering the input location of the disturbance. Moreover, to reduce repeatable runout, an experiment involving a feed‐forward control system including an adaptive FIR filter was performed. As a result, the head‐positioning accuracy was improved by approximately 15 percent compared to the case without feed forward. A 0.15‐μm head‐positioning accuracy was achieved. This level of accuracy means that a track density of 310 tracks/mm (8100 TPI) can be realized.
Low‐cost and high‐quality method of outline font transformation
Authors: Wada Hiroshi , Wakisaka Shinji , Sato Hiroko , Hayashi Shigeo , Kiriyama Norio 
Published: July 2007

AbstractThe outline font is used widely in operational amplifier (OA) equipment since the expansion and modification of a character can be realized with a high quality. The authors developed a system which realizes LSI with a low cost that can expand the outline font with a high quality, aiming at the installation on a low‐cost note‐type word processor. The proposed system executes the character correction, the affine transformation, the third‐order Bezier curve interpolation, the outline generation, the painting, and the memory clear processings which are needed in the outline font expansion.The processings are divided into two blocks from the viewpoint of the processing time, and the blocks are processed by a pipeline. The vertical/horizontal scaling of the character is indispensable as a function of the word processor. The vertical/horizontal operation is included in the operation matrix of the affine transformation, which helps to suppress the increase of the processing time.To cope with the fluctuation of the line width due to the operation error, a powerful character correction function is installed in order to improve the quality. By those considerations of the architecture, all outline font expansion processings are installed on the single‐chip LSI, which is realized on 8.5 mm × 8.5 mm, by CMOS 1.0‐μm process. The expansion speed of 860 characters/s (64 × 64 dot) is realized.
Formation of copper interconnects by the reflow of sputtered copper films
Authors: Abe Kazuhide , Harada Yusuke , Hashimoto Keiichi , Onoda Hiroshi 
Published: July 2007

AbstractThe formation of Cu interconnects using conventional sputtering and reflow processes has been studied. The use of W, Mo, and TiN underlayers makes it possible to fill grooves with Cu at reflow temperatures as low as 450°C. There is a close relationship between filling characteristics and agglomeration. Cu films agglomerate more easily on W, Mo, and TiN underlayers than on TiW and Ta underlayers because of their low Cu wetta‐bility. It was found also that Cu agglomeration was affected drastically by underlayer surface roughness. By adding the CMP process to the conventional sputtering and reflow processes, Cu interconnects down to 0.6 jim in width have been fabricated successfully. The resistivity of the interconnects is about 1.9 μω.cm.