bluuebunny/crossref_metadata_2025_split huggingface dataset:
Network recognition for VLSI mask pattern data
Authors: Fujiki Kunimitsu 
Published: July 2007

AbstractNetwork recognition processing for obtaining circuit connections from mask data (mask pattern) is a keystone of test processing in order to obtain complete mask data before manufacturing IC. In this paper, we describe an algorithm to process trapezoidal mask data which are accurately processed in network recognition processing, a mask patch processing method in which part (mask patch) of the large‐scale mask data that is covered by a newly introduced patch figure is independently processed, and a comparison processing method which uses the decomposed region of the mask patch, and the equation to estimate the processing time from the number of the input mask data.By using the mask patch processing method, restriction of the number of input mask data is alleviated, the processing time and the memory needed for processing are decreased, and, at the same time, flexibility for interrupting the operation is enhanced. The processing time of the proposed method is proportional to the number of input mask data. The processing time of applying the proposed method to a 16 k bit dynamic RAM mask data with 608080 mask data and 369962 elements is about 2.2 CPU hours on ACOS/700 computer, and shows good agreement with the estimated processing time, 2.3 hours, from the equation.
Multielement distributed coupled‐line constant‐resistance circuit with frequency multiplication characteristics
Authors: Sakagami Iwata , Suzuki Masatoshi , Miki Nobuhiro , Nagai Nobuo , Hatori Kozo 
Published: July 2007

AbstractThe microwave‐band distributed‐parameter constant‐resistance π‐type circuit composed of multistage two‐wire coupled lines and three resistances can be used as frequency multipliers which generate clock pulses 1010,…, 1–1, 1–1,…. The realization condition is discussed in this paper. The n‐section coupled line is represented by the equivalent signal flow graph where the delay line is considered delay element z−1. The transfer function in the z‐region is expressed by reflection coefficients at each section alone. The frequency‐multiplying circuit presented in this paper is composed of passive elements alone and is free from the external temperature variation. The experimental example is presented to confirm the validity of the theory.
Algorithms of two‐dimensional image identification and restoration based on an extended stochastic semi‐causal image model
Authors: Mizutani Hiroshi , Sugimoto Sueo 
Published: July 2007

AbstractThis paper is concerned with a new digital processing approach for restoration of additive‐noise‐corrupted images without using a priori statistical information concerning the autocovariance function of the original image field and the variance of noise.Based upon an extended stochastic semi‐causal image model, the method mainly contains two algorithms of image identification and estimation. The algorithm for image identification consists of maximum‐likelihood estimation of unknown parameters and determination of the optimum image model by an information criterion (AIC). Furthermore, recursive Kalman estimation techniques are applied to restore the noise‐corrupted images.
Experiments on the broad‐band operation of stripline Y circulators loaded with a pair of coaxially combined Bi‐ferrite composites
Authors: Nagao Tsukasa , Tanaka Zengo , Umatani Kenji 
Published: July 2007

AbstractWideband operation of a stripline Y‐circulator has been realized below resonance with a coaxially combined two‐layer composite ferrite of nonuniform thickness. The composite ferrite (henceforth referred to as the composite element) consists of a thick ferrite disk with high saturation magnetization and a thin ferrite ring with low saturation magnetization. The circulator consists of tapered striplines and a composite element installed in a stripline Y‐junction and is operated with a uniform applied magnetic field. The insertion loss is less than 0.6 dB and the relative bandwidth is greater than 40% for 20 dB isolation. Circulation takes place at 4–5 different frequencies and is wideband. The paper describes the resonant mode characteristics, the relation between the Y‐junction shape and coupled line width and the structural factor of a composite element of nonuniform thickness.
Polarization characteristics of twisted single‐mode optical fibers
Authors: Namihira Yoshinori , Kudo Masaaki , Mushiake Yasuto 
Published: July 2007

AbstractBecause of complexity in the refractivity distribution of the twisted optical fiber, the theoretical study on the polarization characteristics is difficult. Therefore an experimental investigation is made first. A simple model is proposed to explain generation of cross‐polarization components in case of linearly polarized wave incidence. A generalized tensor permittivity applicable to a twisted elliptic‐core fiber is derived. For the circular‐core fiber, the off‐diagonal elements of the tensor have the θ‐z component ϵθz only. For the elliptic‐core fiber, both the r‐θ components ϵrθ and the r‐z component ϵrz appear as the off‐diagonal components. The polarization characteristics are analyzed by combining the even and odd modes of HE11 mode which is a fundamental mode in the single‐mode optical fiber.
Image reconstruction of long‐wavelength holograms by digital filter technique
Authors: Yamamoto Tsuyoshi , Aoki Yoshinao 
Published: July 2007

AbstractA digital filter is used to reconstruct images from Fresnel‐transformed holograms by directly performing an inverse Fresnel transform with respect to a fixed plane which is defined by special parameters of propagation. In sampling holograms at the sampling interval Δx, the sampled propagator becomes a periodic function for sampling number N at distance 3p. An efficient digital filter can be constructed when N is an even squared number. The present method is also applicable to the hologram constructed at the propagation distance other than 3p if a corrected phase function is used. According to the computer simulation for comparison with other methods, the images reconstructed by the present method are as good as that by the one‐time Fourier transform method. This digital filter technique requires more computation than the FFT method, but it allows effective parallel processing and fast hardware realization.
A design method of super‐wideband pulse amplifiers
Authors: Ohue Kenji , Tsuyuki Shigeru 
Published: July 2007

AbstractSuper‐wideband amplifiers have become necessary in order to realize super‐highspeed digital transmission above 1 Gbit/s. In this paper a super‐wideband amplifier is realized based on a design method which makes practical use of the voltage gain and input impedence peaking effect due to the excessive phase shift of transistor. First, a single‐stage transistor unit amplifier is taken as a basic building block. These individual stages are then combined so as to simplify the design method. It is shown that the most suitable circuit for realizing wideband characteristics is that of voltage‐feedback unit amplifiers in cascade and with flattening circuits of parallel CR in the front. Also, from experiments using packaged bipolar transistor (fT = 10GHz), the characteristics of 4.3GHz high‐band cutoff frequency and 31 dB (6.2 dB per stage) are obtained.
Balanced helical antenna with tapered open ends
Authors: Yamauchi Junji , Nakano Hisamatsu , Mimaki Hiroaki 
Published: July 2007

AbstractRadiation characteristics of a balanced helical antenna with tapered open ends operating in both polarizations are described and compared with those of a balanced uniform helical antenna (UH). The effect of the taper which heretofore has been treated only experimentally, is evaluated numerically in detail. First, using an integral equation with a simplified kernel, we derive the current distributions on an arm with 4 to 10 turns of windings. Next, we calculate the radiation characteristics from the current distributions thus obtained. We find that variations of the axial ratio are small when the gain is almost equal to that of the UH. From the frequency characteristics over 2.6 to 4.5 GHz, we find that the suppression of the reflected current at the tapers is maintained over a wide bandwidth. From the theory and experiment, the fluctuation of the input impedance vs. the frequency is smaller than that in the UH. Due to the taper at the open ends, degradation of the axial ratio in the UH at high frequencies is removed.
Low‐distortion GaAs varactor diodes
Authors: Hara Tohru , Niikura Ikuo , Toyoda Nobuyuki 
Published: July 2007

AbstractSince a GaAs varacter diode has higher Q than a Si diode, it has been widely used for microwaves. This diode must have a hyper‐abrupt junction so as to cover a wide frequency band. However, there are technical limitations in the case of GaAs and up to the present it is realized by the double epitaxial growth method. It has been clear from measurement that diodes fabricated by the double epi‐method gives rise to large nonlinearity of capacitance with respect to voltage, which causes waveform distortion and cross‐modulation. In this paper the low‐distortion feature of a GaAs hyper‐abrupt junction diode using the novel multiple Siion implantation technique will be presented. A detailed device design for low distortion as well as the fabricated diode characteristics will be given.
Foundations on the realization theory of two‐dimensional arrays
Authors: Matsuo Tsuyoshi , Hasegawa Yasumichi , Niinomi Shigeru , Togo Makoto 
Published: July 2007

AbstractRealization theory for non‐linear systems is now quite firmly established. As an application of the theory a problem in figure realization, representing a new kind of realization problem, is considered. The problem is to find the necessary and sufficient system of rules for reconstructing a given figure (two‐dimensional array). The commutative linear representation system is considered to provide the set of rules for generating the figure. The array realization theorem can be stated as follows. For any given array there exist at least two canonical commutative linear representation systems which realize the array, and any two canonical commutative linear representation systems are isomorphic. Circumstances requiring computer treatment of figures are becoming more frequent. The theory of array realization presented in this paper can serve as a basis for figure coding theory. Examples are given of the behavior (figures) of one‐dimensional and two‐dimensional commutative linear representation systems, and the relation between the commutative linear representation system and the two‐dimensional system is discussed.
On interleaved codes for error‐correcting codes
Authors: Ohkubo Masaya , Imai Hideki 
Published: July 2007

AbstractInterleaving for error‐correcting codes is a method of composing a long‐burst‐error‐correcting code with combined short‐burst‐error‐correcting codes or random‐error‐correcting codes. The method is now employed in a wide variety of fields, such as communications, memory systems and PCM recording and is quite useful in increasing the reliability of such systems. However, there has been no detailed theoretical study of interleaving, although it has been the subject of numerous practical studies. A systematic study of its theoretical aspects and some new interleaving techniques are presented here. It is shown that, according to their construction, interleaved codes can be classified into the complete‐block type, convolutional type and incomplete‐block type, among which the incomplete‐block type is newly proposed. Other classifications of interleaving methods are made according to their types and numbers as well as their decoding methods. Next we review different trends in interleaving relevant to the types of codes to be used as the number of codes is changed. We then discuss an interleaving method with codes encoded by word units as well as an error‐detection code conduct a comparative investigation of the error‐correcting capability and encoding capability and encoding complexity as well as decoding from the viewpoint of construction. It is then shown that the incomplete‐block structure has an intermediate position between the complete‐block type and the convolutional type.
Design method of monolithic crystal filters having phase inverting auxiliary electrode
Authors: Kobayashi Masaki 
Published: July 2007

AbstractNuch has been reported on the analysis and design of the quartz monolithic crystal filter (MCF). Since the mechanical coupling between contiguous energy trapping resonators is dependent on the cutoff mode, the propagation phase is independnet of the resonator spacing. This paper analyzes the MCF with phase inverting electrodes and establishes a design method for solution to the above restriction. First, we derive an approximation to the resonator coupling coefficient and compare the effect of the phase inverter on the center frequency of the filter with rigorously obtained data. Next, we study the effect of unwanted modes on the transfer characteristics of the filter. Finally, we describe the design method and compare the data with experimental values. The optimum values of the width of the phase inverter and of the decrease in frequency are given in terms of the resonant frequency and the frequency reduction of the resonator. These relations are summarized in graphical form to facilitate the design. The phase inverter tends to increase the center frequency of the filter and the amount of increase must be taken into account in the design stage. By studying the transfer characteristics of the MCF based on the present design procedure, we can improve the symmetry of the attenuation in the stopband.
Design of E‐plane cosecant square beam horn antennas based on ray theory and their radiation characteristics
Authors: Sha Kokusho , Suzuki Michiya , Nakata Waichi , Adachi Saburo 
Published: July 2007

AbstractA new method of analyzing and designing a nonplanar aperture‐type E‐plane cosecant square beam horn antenna is proposed. This new method is based on the ray theory. The experimental results show that the computed radiation patterns are in good agreement with the measured patterns. This proposed method enables one to design a high‐gain cosecant square beam horn antenna of simple structure with E‐plane sectional horn whose aperture length is about 12 wavelengths.
Impulse response of contradirectional couplers
Authors: Takai Shuuetsu , Mishima Teruhito , Sakuraba Ichiro 
Published: July 2007

AbstractThis paper discusses the impulse response of optical components such as contradirectional couplers and corrugated waveguide filters. The analysis is based on the coupled mode theory which utilizes the main forward and backward modes in the absence of higher harmonics.The impulse response of the forward and backward modes is derived in a form corresponding to repeated reflections at two ends of the system. As for the backward modes, the behavior of reflected waves is related to the coupling length. The impulse responses of transmitted and reflected waves are derived and their pulse responses are analyzed by the convolution integral.
Computer simulated reproduction process with nonlinear magnetic heads
Authors: Koshimoto Yasuhiro , Mikazuki Tetsuo 
Published: July 2007

AbstractTo upgrade magnetic recording equipment consideration anticipated is given to the construction of an electromagentic conversion using high‐permeability magnetic media in order to obtain high output with high resolution power. In the case of obtaining high reproduction output, the nonlinear magnetism of the reproduction head can affect the reproduction properties, but presently there is no report on the head operation with nonlinearity taken into account. In this paper, the reproduction process with nonlinear magnetic head is simultaed numerically and the magnetic field, permeability and magnetic flux distributions in the head as well as the effect of the nonlinearity of the head core material are analyzed. Results show that the core permeability decreases locally because of local concentration of magnetic flux due to the presence of recorded media and the permeability decreases significantly when the medium position giving rise to maximum output lies in the vicinity of the gap. The reason for degradation of the reproduction characteristics in heads using material with low saturation flux density can be explained by the fact that the low‐permeability region in the vicinity of the gap gives rise to an effective gap increase.
A design of back‐feed type circularly polarized microstrip disk antennas having symmetrical perturbation element by one‐point feed
Authors: Haneishi Misao , Yoshida Shinichiro , Tabeta Masashi 
Published: July 2007

AbstractA one‐point back‐feed type circularly polarized microstrip disk antenna is investigated. To establish a design procedure, (1) the operating condition for circular polarization is studied and design formulas and data are presented and (2) the fabrication and radiation characteristics of arrays consisting of the present circularly polarized disk antenna element are discussed. It is demonstrated that this class of antennas can serve as a useful form of circularly polarized array element. Further, in order to analyze the mutual coupling of such antenna elements, the resonance and inter‐element mutual admittance of an array consisting of two disk antennas located on the same plane are determined. The fundamental information on the mutual coupling thus obtained is presented for a design aid. Using these results, a circularly polarized array is realized with good axial ratio and boresight ratio less than 0.5 dB.
Perturbation analysis of corrugated dielectric waveguide with application to millimeter‐wave filters
Authors: Ohira Takahashi , Tsutsumi Makoto , Kumagai Nobuaki 
Published: July 2007

AbstractThe propagation characteristics of the TM mode wave in a two‐dimensional dielectric slab with a sinusoidal corrugation are theoretically analyzed. A coupled‐mode equation is derived for describing the coupling between the forward and backward waves near Bragg frequency caused by the corrugation and the Brillouin diagram is clarified. The theoretical characteristics of the reflection filter made of a dielectric slab with a finitely long corrugation are investigated. Using a Teflon slab loaded with a rectangular corrugation, experiments are conducted on the reflection filter in the 40‐GHz band and the results are compared with theoretical values. It is found that such filter characteristics as the Bragg frequency, return loss and stopband half‐width agree well with theoretical predictions.
Analysis of coplanar striplines on an anisotropic substrate using Galerkin's method
Authors: Hayashi Yoshio , Kitazawa Toshihide , Sasaki Shinji 
Published: July 2007

AbstractA unified analysis approach is shown for obtaining the quasistatic and dispersive characteristics of coplanar Striplines on a uniaxial anisotropic substrate. Galerkin's method is adopted in the numerical calculations and the basis functions are determined systematically by use of Chebyshev polynomials with the result that solutions with desired accuracy can be obtained efficiently. In general, in coupled striplines large errors occur when the current distribution function is to be determined solely by its fringing effect. In the case of sapphire substrate, the accuracy of solution is investigated and its propagation wavelength as well as characteristic impedance are obtained and shown in graph. In these graphs the quasistatic characteristics obtained from the electrostatic approximation and the hybrid mode dispersion are compared so that a rough criterion of the error due to the electrostatic approximation can be estimated. The quasi‐static characteristics of a uniaxial anisotropic substrate line can be characterized by its effective and equivalent isotropic substrate [1]. The dispersion of the isotropic substrate line is obtained and compared with that of the original anisotropic line.
Automatic laser radar systems for measurement of atmospheric pollutants
Authors: Kimura Hiroichi , Shimada Takashi 
Published: July 2007

AbstractLaser radar employing the Mie scattering principle for monitoring atmospheric pollutants has been widely used because of its capability of remote measurement of the distribution of aerosols. For practical purposes, however, the accuracy, measurable range and quantitativeness of measurement have been major drawbacks in conventional systems. In order to overcome such drawbacks and increase the practicality, a laser radar system with computer automatic measuring and data processing functions has been developed. In this system the Mie‐scattered signal is quantified so as to represent the dust concentration and the signal‐to‐noise‐ratio is improved by employing an averaging process. Four standard methods of measuring the three‐dimensional distribution of the dust concentration are presented. According to field test results, averaging process proves to be quite effective and the measured values obtained by the system agree well with those obtained by a conventional digital dust concentration indicator. By examples of the measurement of dust concentration at various altitudes the system is shown to be useful not only for the study of atmospheric pollution but also for the continuous monitoring and forecasting of pollution.
Approximate representations of a class of nonuniform lines based on approximate mixed lumped‐distributed representations of linear taper lines
Authors: Kobayashi Kunikatsu , Nemoto Yoshiaki , Sato Risaburo 
Published: July 2007

AbstractThe nonuniform line containing the binomial‐form transmission line of odd order can be approximated by the lumped‐distributed circuit at frequencies below π/2 (rad) in electrical length. The rigorous solution for telegraph equation of odd‐order binomial‐form lines with the characteristic impedance given by (ax±b)±n (where a and b are constant and n is odd number) is derived and the approximate solution is obtained for a case where four‐terminal constants of the linear taper line with n=1 are truncated at finite terms. It is shown that the linear taper line can be approximated by the lumped‐distributed circuit at frequencies below π/2 (rad) in electrical length. Next, Kuroda's identity is applied to the lumped nonuniform distributed circuit consisting of the linear taper line and lumped reactance to show that the nonuniform line containing binomial‐form transmission lines can be obtained as a cascade connection of the linear taper line and lumped reactance. Finally, the nonuniform line is approximated by the lumped‐distributed circuit at frequencies below π/2 (rad).
Computation of periodic solutions for polynomial nonlinear equations
Authors: Kawakami Hiroshi , Kobayashi Kunihiro 
Published: July 2007

AbstractThe periodic solution of polynomial nonlinear equations is derived based on Galerkin's procedure. An algorithm for evaluating deterministic equations and elements of Jacobian matrices is presented. This algorithm enables one to determine a periodic solution and to reduce the computation time and procedure. The result is applied successfully to periodic solutions of Duffing's equation, Van der Pols' equation, the pendulum equation, Minorsky's equation, the population growth model with time lag and the difference equation.
Measurement of millimeter‐wave reflection coefficients by using a T‐junction
Authors: Iwasaki Takashi , Nagatsuka Akio , Nemoto Toshio 
Published: July 2007

AbstractA technique of measuring millimeterwave reflection coefficients by using a T junction is proposed. This technique does not require a tuning procedure and frequency conversion. The measurement circuit is composed of a T junction and power meter, where system constants of the circuit are calibrated in advance by using a sliding short. The standard waveguides are used to shift the phase angle of the reflection coefficients of a load under test and the unknown reflection coefficient is computed from the powermeter reading. The measurement result at 34.0 GHz indicates the validity of this technique. The error was estimated as about 2.7% at the 0.3 magnitude of the reflection coefficient.