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541-560hit(701hit)

  • Simultaneous Measurements of Temperature and Strain Using Stimulated Brillouin Scattering in GeO2-Doped Core and Dispersion Shifted Fiber

    Ralph POSEY, Jr.  Sandeep T. VOHRA  Alan B. TVETEN  

     
    PAPER-Distributed Sensing

      Vol:
    E83-C No:3
      Page(s):
    413-417

    Simultaneous measurements of temperature and strain were demonstrated by measuring the stimulated Brillouin scattering frequency shift and gain in two separate types of optical fibers: dispersion shifted and special GeO2-doped optical fiber. This novel approach allows for a hybrid frequency division and time division multiplexing scheme for developing advanced distributed strain sensing. The preliminary measurements show a temperature resolution of approximately 1.6 and a strain resolution of 32 µε.

  • Very Long Baseline Connected Interferometry via the STM-16 ATM Network

    Hitoshi KIUCHI  Yukio TAKAHASHI  Akihiro KANEKO  Hisao UOSE  Sotetsu IWAMURA  Takashi HOSHINO  Noriyuki KAWAGUCHI  Hideyuki KOBAYASHI  Kenta FUJISAWA  Jun AMAGAI  Junichi NAKAJIMA  Tetsuro KONDO  Satoru IGUCHI  Takeshi MIYAJI  Kazuo SORAI  Kouichi SEBATA  Taizoh YOSHINO  Noriyuki KURIHARA  

     
    PAPER-ATM Switch and System Development

      Vol:
    E83-B No:2
      Page(s):
    238-245

    The Communications Research Laboratory (CRL), the National Astronomical Observatory (NAO), the Institute of Space and Astronoutical Science (ISAS), and the Telecommunication Network Laboratory Group of Nippon Telegraph and Telephone Corporation (NTT) have developed a very-long-baseline-connected-interferometry array, maximum baseline-length was 208 km, using a high-speed asynchronous transfer mode (ATM) network with an AAL1 that corresponds to the constant bit-rate protocol. The very long baseline interferometry (VLBI) observed data is transmitted through a 2.488-Gbps [STM-16/OC-48] ATM network instead of being recorded onto magnetic tape. By combining antennas via a high-speed ATM network, a highly-sensitive virtual (radio) telescope system was realized. The system was composed of two real-time VLBI networks: the Key-Stone-Project (KSP) network of CRL (which is used for measuring crustal deformation in the Tokyo metropolitan area), and the OLIVE (optically linked VLBI experiment) network of NAO and ISAS which is used for astronomy (space-VLBI). These networks operated in cooperation with NTT. In order to realize a virtual telescope, the acquired VLBI data were corrected via the ATM networks and were synthesized using the VLBI technique. The cross-correlation processing and data observation were done simultaneously in this system and radio flares on the weak radio source (HR1099) were detected.

  • A 1.2 V, 30 MIPS, 0.3 mA/MIPS and 200 MIPS, 0.58 mA/MIPS Digital Signal Processors

    Hiroshi TAKAHASHI  Shintaro MIZUSHIMA  

     
    PAPER

      Vol:
    E83-C No:2
      Page(s):
    179-185

    High-speed and low-power DSPs have been developed for versatile applications, especially for digital communications. These DSPs contain a 16-bit fixed point DSP core with multiple buses, highly tuned instruction set and low-power architecture, featuring 0.45 mA/MIPS, 100-120 MIPS performance by a single CPU core, 200 MIPS performance by dual CPU core architecture, respectively and also contain a 1.2 V low-voltage DSP core with 30 MIPS performance for super low-power applications. In this paper, new architecture VIA2 programming ROM for high-speed and new D flip-flop circuit considering the impact of pocket implantation process for low power are discussed, including key C-MOS process technology.

  • Fuzzy Inference in Engineering Electromagnetics: An Application to Conventional and Angled Monopole-Antenna

    Majid TAYARANI  Yoshio KAMI  

     
    PAPER-Electromagnetic Theory

      Vol:
    E83-C No:1
      Page(s):
    85-97

    The abilities of fuzzy inference methods in modeling of complicated systems are implemented to electromagnetics for the first time. The very popular and well known monopole antenna is chosen as a general example and a fast, simple and accurate fuzzy model for its input impedance is made by introducing a new point of view to impedance basic parameters. It is established that a surprisingly little number of input data points is sufficient to make a full model and also the system behavior (dominant rules) are saved as simple membership functions. The validity of the derived rules is confirmed through applying them to the case of thin-angled monopole antenna and comparing the results with the measured. Finally using the spatial membership function context, input impedance of thick-angled monopole antenna is predicted and a novel view point to conventional electromagnetic parameters is discussed to generalize the modeling method.

  • Scattering and Absorption of Electromagnetic Plane Waves by a Multilayered Resistive Strip Grating Embedded in a Dielectric Slab

    Tatyana L. ZINENKO  Akira MATSUSHIMA  Yoichi OKUNO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E82-C No:12
      Page(s):
    2255-2264

    An accurate and efficient numerical solution is presented for a two-dimensional electromagnetic wave scattering from a multilayered resistive strip grating embedded in a dielectric slab. Both E- and H-waves are treated. The problem is formulated into a set of integral equations, which is solved by the moment method accompanied by a regularization procedure. The resultant set of linear algebraic equations has the form of the Fredholm second kind, and therefore yields stable and accurate numerical solutions. The power distribution is computed for several grating parameters. Attention is paid to seek a set of parameters that maximizes absorption in the strips. The low frequency approximate formulas are also derived. This analysis would be useful in designing electromagnetic wave absorbers.

  • Millimeter-Wave Flip-Chip MMIC Structure with High Performance and High Reliability Interconnects

    Masaharu ITO  Kenichi MARUHASHI  Hideki KUSAMITSU  Yoshiaki MORISHITA  Keiichi OHATA  

     
    PAPER-RF Assembly Technology

      Vol:
    E82-C No:11
      Page(s):
    2038-2043

    The flip-chip structure for millimeter-wave MMICs has been investigated to obtain high performance and high reliability. In our approach, an air gap between the MMIC and the alumina substrate was determined so as not to change electrical characteristics from those of the unflipped MMIC. We calculated the proximity effect between the MMIC and the substrate by using 3D-electromagnetic simulator, and found that the air gap should be controlled to be greater than 20 µm. Since the discontinuity of transmission lines at bump interconnects is not negligible above 60 GHz, we constructed the LCR-equivalent circuit for the bump interconnect and confirmed its validity by comparing measurement with calculation. Based on these investigations, the 60- and 76-GHz-band CPW three-stage low noise amplifiers were successfully mounted on the alumina substrate using a thermal compression bonding process. The gain of the flipped 60- and 76-GHz-band MMICs are greater than 18 dB at around 60 GHz and 17 dB at around 76 GHz, respectively. The noise figures are 3.6 dB and 3.9 dB, respectively. The gain and noise performances showed little degradation compared to those of the unflipped MMICs when appropriate bonding conditions are given. We confirmed that the flip-chip structure has high reliability under a thermal cycle test. From these results, flip-chip technology is promising for millimeter-wave applications.

  • A Compact Plastic Package with High RF Isolation by Subsidiary Inner Ground Leads

    Hidetoshi ISHIDA  Kazuo MIYATSUJI  Tsuyoshi TANAKA  Daisuke UEDA  Chihiro HAMAGUCHI  

     
    PAPER-RF Assembly Technology

      Vol:
    E82-C No:11
      Page(s):
    2044-2049

    A novel method to obtain a compact plastic package with higher isolation by providing subsidiary inner ground leads between outer leads is proposed and demonstrated. The effect of the subsidiary ground leads is investigated by using a 3-dimensional electromagnetic field simulation and measuring the fabricated packages. Newly designed package with subsidiary ground leads achieves higher isolation by more than 10 dB at 3 GHz as compared to a conventional package. This package is applied to GaAs SPDT switch IC's. Isolation of the switch IC's is improved by 5 dB at 3 GHz by the subsidiary inner ground leads. The isolation characteristics are discussed based on the equivalent circuit extracted from the simulation results.

  • A Proposition on Floating Gate Neuron MOS Macromodeling for Device Fabrications

    Tadahiro OCHIAI  Hiroshi HATANO  

     
    PAPER

      Vol:
    E82-A No:11
      Page(s):
    2485-2491

    A neuron MOS transistor has a floating gate and multiple input gates which are capacitively coupling with the floating gate. Dramatic reduction in the number of transistors and interconnections was achieved by employing the neuron MOS in circuit designs. Since the neuron MOS gate electrode is electrically floating, it is not necessarily easy to calculate the floating gate potential using circuit simulator SPICE. In order to simulate floating gate neuron MOS circuits, a macromodel which calculates the floating gate potential combining resistances and dependent voltage and current sources has been proposed. Eight kinds of neuron MOS circuits were designed and fabricated by a double polysilicon two level metal 1.2 µ m CMOS process. Utilizing SPICE, all the neuron MOS circuits were confirmed to operate correctly. The apparent threshold voltage as seen from the input gate in the 2-input n-channel neuron MOS transistor is arbitrarily changed by a control gate signal. Multi-input neuron MOS inverters and neuron MOS full adder circuits have been successfully simulated. Moreover, the effectiveness of the proposed macromodel has been experimentally verified by fabricated circuit measurements. Measured results confirmed that 3-input neuron MOS inverter outputs the low level when the number of input gates to which a high level is applied is more than half of all input gates.

  • A Novel Layout Optimization Technique for Miniaturization and Accurate Design of MMICs

    Shin CHAKI  Yoshinobu SASAKI  Naoto ANDOH  Yasuharu NAKAJIMA  Kazuo NISHITANI  

     
    INVITED PAPER-Low Power-Consumption RF ICs

      Vol:
    E82-C No:11
      Page(s):
    1960-1967

    This paper describes a novel layout optimization technique using electromagnetic (EM) simulation. Simple equivalent circuits fitted to EM simulation results are employed in this method, to present a modification guide for a layout pattern. Fitting errors are also investigated with some layout patterns in order to clarify the applicable range of the method, because the errors restrict the range. The method has been successfully adopted to an X-band low noise MMIC amplifier (LNA). The layout pattern of the amplifier was optimized in only two days and the amplifier has achieved target performances--a 35 dB gain and a 1.7 dB noise figure--in one development cycle. The effective chip area has been miniaturized to 4.8 mm2. The area could be smaller than 70% in comparison with a conventional layout MMIC.

  • Application of Mix-Phase Wavelets to Sparsify Impedance Matrices

    Jiunn-Ming HUANG  Jeng-Long LEOU  Shyh-Kang JENG  Jenn-Hwan TARNG  

     
    LETTER-Optical Communication

      Vol:
    E82-B No:10
      Page(s):
    1688-1693

    Effective wavelets to solve electromagnetic integral equations are proposed. It is based on the same construction procedure as Daubechies wavelets but with mix-phase to obtain maximum sparsity of moment matrix. These new wavelets are proved to have excellent performance in non-zero elements reduction in comparison with minimum-phase wavelet transform (WT). If further sparsity is concerned, wavelet packet (WP) transform can be applied but increases the computational complexity. In some cases, the capability of non-zero elements reduction by this new wavelets even better than WP with minimum-phase wavelets and with less computational efforts. Numerical experiments demonstrate the validity and effectiveness of the new wavelets.

  • Analysis of Modified Luneberg Lens Using Exact Solutions

    Haruo SAKURAI  Makoto OHKI  Shogo KOZAKI  

     
    PAPER-Electromagnetic Theory

      Vol:
    E82-C No:10
      Page(s):
    1846-1852

    Analytical solutions have been obtained for the electromagnetic scattering by a modified Luneberg lens with the permittivity of arbitrary parabolic function. They are expressed by four spherical vector wave functions for radially stratified medium which were introduced for the Luneberg lens by C. T. Tai. They consist of the confluent hypergeometric function and a "generalized" confluent hypergeometric function, in which the parameters for the permittivity of arbitrary parabolic function are involved. The characteristics of the modified Luneberg lens are numerically investigated using exact solutions in comparison with that of the conventional Luneberg lens. The bistatic cross section, the forward cross section and the radar cross section are studied in detail. The near-field distribution is also investigated in order to study the focal properties of the Luneberg lens. The focal shifts defined by the distance between the geometrical focal point and the electromagnetic focal point are obtained for various ka (k is the wave number and a is the radius of the lens). The focal shift normalized to the radius of the sphere becomes larger as ka is smaller. However it drops down rapidly for ka5 when the peak of the electric field amplitude appears on the surface of sphere.

  • Multiple-Valued Logic-in-Memory VLSI Architecture Based on Floating-Gate-MOS Pass-Transistor Logic

    Takahiro HANYU  Michitaka KAMEYAMA  

     
    PAPER-Non-Binary Architectures

      Vol:
    E82-C No:9
      Page(s):
    1662-1668

    A new logic-in-memory VLSI architecture based on multiple-valued floating-gate-MOS pass-transistor logic is proposed to solve the communication bottleneck between memory and logic modules. Multiple-valued stored data are represented by the threshold voltage of a floating-gate MOS transistor, so that a single floating-gate MOS transistor is effectively employed to merge multiple-valued threshold-literal and pass-switch functions. As an application, a four-valued logic-in-memory VLSI for high-speed pattern recognition is also presented. The proposed VLSI detects a stored reference word with the minimum Manhattan distance between a 16-bit input word and 16-bit stored reference words. The effective chip area, the switching delay and the power dissipation of a new four-valued full adder, which is a key component of the proposed logic-in-memory VLSI, are reduced to about 33 percent, 67 percent and 24 percent, respectively, in comparison with those of the corresponding binary CMOS implementation under a 0.5-µm flash EEPROM technology.

  • Transient Phenomena of Electromagnetic Waves by the Abrupt Extinction of Interior Terminative Conducting Screen in Waveguide

    Michinari SHIMODA  Ryuichi IWAKI  Masazumi MIYOSHI  Oleg A. TRETYAKOV  

     
    PAPER-Electromagnetic Theory

      Vol:
    E82-C No:8
      Page(s):
    1584-1591

    The problem of transient scattering caused by abrupt extinction of a terminative conducting screen in a waveguide is considered. First, a boundary-value problem is formulated to describe the transient phenomena, the problem in which the boundary condition depends on time. Then, application of the Fourier transformation with respect to time derives a Wiener-Hopf-type equation, which is solved by a commonly known decomposition procedure. The transient fields are obtained through the deformation of the integration path for the inverse transformation and the results are represented in terms of the incomplete Lipschitz-Hankel integrals. Numerical examples showing typical transient phenomena are attached.

  • Extraction of Bibliography Information Based on the Image of Book Cover

    Hua YANG  Shinji OZAWA  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E82-D No:7
      Page(s):
    1109-1116

    This paper describes a new system for extracting and classifying bibliography regions from the color image of a book cover. The same as all the color image processing, the segmentation of color space is an essential and important step in our system; and here HSI color space is adopted rather than RGB color space. The color space is segmented into achromatic and chromatic regions first; and the segmentation is completed after thresholding the intensity histogram of the achromatic region and the hue histogram of the chromatic region. Then text region extraction and classification follows. After detecting fundamental features (stroke width and local label width) text regions are determined by comparing smeared blocks to the original candidate image. Based on the general cover design model, text regions are classified into author region, title region, and publisher region furthermore, and a bibliography image is obtained as a result, without applying OCR. The appearance of the book is 3D reconstructed as well. In this paper, two examples are presented.

  • A TFT-LCD Simulation Method Using Pixel Macro Models

    Hitoshi AOKI  Zhiping YU  

     
    PAPER-Electronic Displays

      Vol:
    E82-C No:6
      Page(s):
    1025-1030

    The full liquid crystal display (LCD) simulation with real transistors and other active components is unrealistic. Because a flat panel display (FPD) includes thin-film-transistors (TFT's) whose number is, at least, the number of total pixels. It hits the simulation limit of SPICE if the number of transistors are more than 0.5 million. This paper demonstrates a new, fast, and effective simulation method for a full LCD panel. The method makes it possible to simulate large LCD panels whereas the conventional method cannot handle. The simulation circuit consists of a-Si TFT model presented earlier, the liquid crystal, the pixel macro models, and interconnects. We show the model parameter extraction and the pixel macro modeling process associated with the simulation results. Using the simulation method presented here some larger LCD panels can be accurately simulated in less than a minute on a workstation.

  • Ribbon-Wire Interconnect Using Parasitic Element

    Hajime IZUMI  Hiroyuki ARAI  Tatsuo ITOH  

     
    LETTER-Microwave and Millimeter Wave Technology

      Vol:
    E82-C No:4
      Page(s):
    662-664

    This paper presents a contact-less connector using proximity coupling through a parasitic element. For example, proximity coupling is used for interconnect of microstrip lines for DC-break structure. We also present a cross wiring structure using this interconnect.

  • New Technologies Doing Much for Solving the EMC Problem in the High Performance Digital PCBs and Equipment

    Hirokazu TOHYA  

     
    PAPER

      Vol:
    E82-A No:3
      Page(s):
    450-456

    This paper is consisting of the two novel EMC technologies that we have been developed in our laboratory. The first is the technology for measuring the RF (Radio Frequency) nearby magnetic field and estimation of the RF current in the printed circuit board (PCB) by using the small loop antenna with multi-layer PCB structure developed by our laboratory. I introduce the application of our small loop antenna with its physical structure and the analysis of the nearby magnetic field distribution of the printed circuit board applying the discrete Wavelet analysis. We can understand the behavior of the digital circuit in detail, and we can also take measures to meet the specification about the electromagnetic radiation from the digital circuit from the higher order of priority by using these technologies. The second is our proposing novel technology for reducing the electromagnetic radiation from the digital equipment by taking notice of the improvement of the de-coupling in the PCB. We confirmed the remarkable effect of this technology by redesigning the motherboard of the small-sized computer.

  • A Generation Method of Electromagnetic Fields Rotating at a Low Speed for the Immunity Test

    Kimitoshi MURANO  Yoshio KAMI  

     
    LETTER-Electromagnetic Compatibility

      Vol:
    E82-B No:3
      Page(s):
    567-569

    A novel method for the radiated immunity test is proposed. The method is to generate controlled electromagnetic fields applying in arbitrary directions to an under test. The fields rotate at a low speed controlled electrically so that the immunity characteristics may be known in more detail. The primal characteristics of the fields generated by a trial benchtop setup are investigated.

  • Passive Range Sensing Techniques: Depth from Images

    Naokazu YOKOYA  Takeshi SHAKUNAGA  Masayuki KANBARA  

     
    INVITED SURVEY PAPER

      Vol:
    E82-D No:3
      Page(s):
    523-533

    Acquisition of three-dimensional information of a real-world scene from two-dimensional images has been one of the most important issues in computer vision and image understanding in the last two decades. Noncontact range acquisition techniques can be essentially classified into two classes: Passive and active. This paper concentrates on passive depth extraction techniques which have the advantage that 3-D information can be obtained without affecting the scene. Passive range sensing techniques are often referred to as shape-from-x, where x is one of visual cues such as shading, texture, contour, focus, stereo, and motion. These techniques produce 2.5-D representations of visible surfaces. This survey discusses aspects of this research field and reviews some recent advances including video-rate range imaging sensors as well as emerging themes and applications.

  • Motion and Shape from Sequences of Images under Feature Correspondences

    Jun FUJIKI  

     
    INVITED SURVEY PAPER

      Vol:
    E82-D No:3
      Page(s):
    548-557

    The reconstruction of motion and structure from multiple images is fundamental and important problem in computer vision. This paper highlights the recovery of the camera motion and the object shape under some camera projection model from feature correspondences especially the epipolar geometry and the factorization method for mainly used projection models.

541-560hit(701hit)