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[Keyword] electromagnetic field(39hit)

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  • Precise Measurement of Microwave Permittivity Based on the Electromagnetic Fields in a Cavity Resonator with Finite Conductivity Walls

    Hiroyuki TANAKA  Akihiro TSUTSUMI  

     
    PAPER-Measurement

      Vol:
    E86-C No:12
      Page(s):
    2387-2393

    In this paper, we calculated resonant frequency and unloaded Q-factor for the TM0i0 resonant mode excited in a cylindrical cavity composed of walls with finite conductivity and with a dielectric rod loaded coaxially along the central axis. Formulation for the calculation is made using the mode-matching method. Convergence of the calculation is checked. Values calculated by the present method for various combinations of dimensions, permittivity, and conductivity of the inner-components of cavity are compared with those calculated by a conventional method formulated using loss-less electromagnetic fields of cavity. Although the difference between the values calculated by those two methods is usually small, it is found that the difference increases as permittivity of dielectric rod increases and becomes about 10-6 in reciprocal of unloaded Q-factor of the loaded cavity in a presented case.

  • Simulation of Substrate Currents

    Wim SCHOENMAKER  Peter MEURIS  Wim MAGNUS  Bert MALESZKA  

     
    PAPER

      Vol:
    E86-C No:3
      Page(s):
    433-438

    Recently, a new approach was presented to determine the high-frequency response of on-chip passives and interconnects. The method solves the electric scalar and magnetic vector potentials in a prescribed gauge. The latter one is included by introducing an additional independent scalar field, whose field equation needs to be solved. This additional field is a mathematical aid that allows for the construction of a gauge-conditioned, regular matrix representation of the curl-curl operator acting on edge elements. This paper reports on the convergence properties of the new method and shows the first results of this new calculation scheme for VLSI-based structures at high frequencies. The high-frequent behavior of the substrate current, the skin effect and current crowding is evaluated.

  • An Object-Oriented Design of Electromagnetic Wave Simulator for Multi Schemes

    Hiroko O. UEDA  Masashi NAKATA  Takesi MURATA  Hideyuki USUI  Masaki OKADA  Koichi ITO  

     
    LETTER

      Vol:
    E84-C No:7
      Page(s):
    967-972

    We propose the architecture of efficiently and flexibly extensible solver system for electromagnetic wave simulations, that can load multi kinds of schemes such as Finite-Difference Time-Domain (FDTD) scheme, Finite Element Method (FEM), and a circuit simulator, with various boundary conditions in the system. Object-oriented approach is a promising method for efficient development of the flexible simulator. The primary object in the architecture is found through our object-oriented analysis as decomposed "region" from whole the simulation space. The decomposed region is considered to be the stage on which the electromagnetic fields play under the local rules. Developers who will extend the functionality of the system can add new classes inherited from the abstract classes in our design depending on the grid structure, the scheme, or the boundary processing method.

  • 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.

  • Noncubic Cell Time-Domain Analysis of Scattering by Dielectric Cylinders

    Norihiko HARADA  Mitsuo HANO  

     
    PAPER

      Vol:
    E81-C No:12
      Page(s):
    1779-1783

    We have proposed an algorithm to apply perfectly matched layer (PML) absorbing boundary condition to the noncubic cell time-domain method. The extended method has a merit of flexibility in truncating the computational domain by the use of a curvilinear PML. In this paper we apply a circular PML for computing the scattered fields of a dielectric cylinder or cylindrical shell of arbitrary cross section shape. Numerical results are presented to demonstrate the accuracy of this method.

  • Generation of the Standard EM Fields with Arbitrary Wave Impedance at the Center of a TEM Cell

    Jae-Hoon YUN  Hyuck-Jae LEE  Jung-Ki KIM  

     
    LETTER-Electromagnetic Compatibility

      Vol:
    E81-B No:6
      Page(s):
    1286-1289

    A technique for generating the standard EM fields with arbitrary wave impedance at the center of a TEM cell is proposed in this letter. We can realize the experimental system and obtain the measured results to agree well with the calculated results. This technique is useful for the EMS test and the calibration of EM probe because the wave impedance can be easily adjusted only with step attenuator.

  • Analysis of Electromagnetic Field inside Equipment Housing with an Aperture

    Hiroaki KOGURE  Hideki NAKANO  Kohji KOSHIJI  Eimei SHU  

     
    PAPER

      Vol:
    E80-B No:11
      Page(s):
    1620-1624

    This paper presents a method of analyzing the electromagnetic field inside an equipment housing. The electromagnetic field is assumed to be coming from outside and coupled into the housing through an aperture on the housing surface. The analysis is based on the transmission-line modeling method. Results of the analysis show a good agreement with the results of measurement. Also, it is found that the coupling through the aperture shows peaks at some frequencies that depend almost only on the structure of the housing and aperture and, therefore, can be estimated at the time of equipment design.

  • Measurement of Electromagnetic Field Distribution in Waveguide Based on Analogy between H-Plane Waveguide- and Trough-Type Planar Circuit

    Tetsuo ANADA  Takaharu HIRAOKA  JUI-PANG Hsu  

     
    PAPER

      Vol:
    E80-B No:5
      Page(s):
    686-691

    A detailed investigation of the electromagnetic field distributions inside waveguide circuits is useful for physical understanding, studies of electromagnetic coupling effects for EMC and EMI and for optimization of waveguide circuit designs. In this paper, we describe how to calculate and measure the two-dimensional electromagnetic field distributions inside waveguide-type planar circuits, making use of an analogy between H-plane waveguide- and trough-type surface-wave planar circuits. The measurement results are in good agreement with the results of the numerical analysis based on the normal mode expansion method.

  • Near Fields Radiated from a Long Slot on a Circular Conducting Cylinder

    Masao KODAMA  Kengo TAIRA  

     
    LETTER-Electromagnetic Theory

      Vol:
    E79-C No:2
      Page(s):
    249-251

    New series expressing the radiation fields from both axial and circumferential slots on a circular conducting cylinder are derived. These new series converge rapidly even for near fields. This letter includes useful figures showing characteristics of near fields calculated numerically using the new series.

  • Radiated Emission Estimation of a Metallic Enclosure Model Source by Inverse-Forward Analysis

    Shose HAYASHI  Koichiro MASUDA  Ken-ichi HATAKEYAMA  

     
    PAPER

      Vol:
    E78-B No:2
      Page(s):
    173-180

    For estimating the radiated emission from a metallic enclosure, the authors have developed a numerical computational method which applied inverse analysis. A metallic enclosure containing a loop antenna was set up to be a model source for the numerical analysis. Magnetic fields around the enclosure were measured by measurement systems fabricated in the authors' laboratory. Using the measured magnetic fields, current distributions on the enclosure surface were determined by means of an inverse analysis utilizing the least squares method. From this surface current distribution, the electromagnetic field distributions were estimated by forward analysis on a cylindrical surface 3.0m in radius. The amount of the error in the estimated fields distribution was also discussed.

  • Estimation of Source Particle Trajectories from Far Electromagnetic Fields Using the Linard-Wiechert Superpotentials: Twin Particles System

    Hideki KAWAGUCHI  Toshihisa HONMA  

     
    PAPER

      Vol:
    E77-C No:11
      Page(s):
    1802-1807

    A particle trajectory estimation method from far electromagnetic fields are discussed in this paper. Authors have already presented a trajectory estimation method for single particle system and good agreements between a source particle trajectory and an estimated one have been obtained. For this, this paper discusses twin particles system as an examples of multi-particles systems for simplicity. First of all, it is pointed out that far electromagnetic fields from the twin particles system show quite different aspect from the single particle system using an example, radiation patterns produced by two particles which carry out circular motion. This result tells us that any trajectory estimations for general multi-particles system are almost impossible. However, it is shown that when the distance between the particles is small, the estimation method for the single particle system can be applied to the twin particles system, and that twin particles effects appear as disturbance of estimated trajectory.

  • Development of a Technique to Evaluate Human Exposure to Ion-Current Fields Using Boundary Element Method--For Environmental Assessment of High Voltage Transmission Lines--

    Masaji YAMASHITA  Koichi SHIMIZU  Goro MATSUMOTO  

     
    PAPER

      Vol:
    E77-B No:6
      Page(s):
    714-718

    To study the biological effects of the ion-current commonly found under ultra-high voltage DC transmission lines, a technique was developed to evaluate the human exposure to the ion-current field. This technique is based on numerical analysis using the boundary element method. The difficulty of handling the space charge in the calculation was overcome by assuming a lumped source ion-current. This technique is applicable to a three-dimensionally complex object such as a human body. In comparison with theoretical values, the accuracy of this technique was evaluated to be satisfactory for our purposes. It was then applied to a human body in an ion-current field. The distribution of the electric field along the body surface was obtained. The general characteristics of the field distribution were essentially the same as in those without space charges. However, it was found that the strength of the field concentration was significantly enhanced by the space charges. Further, the field exposure when a human body was charged by an ion-current was evaluated. As the charged voltage increases, the position of the field concentration moves from a human's head toward his legs. But the shock of micro spark increases. This technique provides a useful tool for the study of biological effects and safety standards of ion-current fields.

  • Biological Effects of ELF Electric Fields--Historical Review on Bioengineering Studies in Japan--

    Goro MATSUMOTO  Koichi SHIMIZU  

     
    INVITED PAPER

      Vol:
    E77-B No:6
      Page(s):
    684-692

    The studies on the biological effects of ELF electric fields conducted in Japan are reviewed. Among international studies, they are characterized as the studies from the viewpoint of bioengineering. In early studies, the safety standard of high voltage transmission lines was determined by a distinct biological effect, i.e., the sensation of the spark discharge caused by electrostatic induction. In numerical analysis, the field coupling to both animal and human bodies became well understood. Some new measurement techniques were developed which enabled us to evaluate the field exposure on a human body. A system was developed to realize the chronic exposure of an electric field on mice and cats. An optical telemetry technique was developed to measure the physiological response of an animal when it was exposed to an electric field. An ion-current shuttle box was developed to investigate the behavioral change of a rat when it was exposed to an ion-current as well as an electric field. In animal experiments, a mechanism of sensing the field was investigated. The cause of the seasonal change of field sensitivity was found. In cases of chronic exposure, suppression of growth was suspected. In shuttle box studies, an avoidance behavior from an ion-current was quantified. To find whether there are any adverse or beneficial effects of the field exposure on human beings, further study is required to clarify the mechanisms of the biological effects.

  • Analysis of Transient Electromagnetic Fields Radiated by Electrostatic Discharges

    Osamu FUJIWARA  Norio ANDOH  

     
    LETTER-Electromagnetic Compatibility

      Vol:
    E76-B No:11
      Page(s):
    1478-1480

    For analyzing the transient electromagnetic fields caused by electrostatic discharge (ESD), a new ESD model is presented here. Numerical calculation is also given to explain the distinctive phenomenon being well-recognized in the ESD event.

  • On Precision of Solutions by Finite-Difference Time-Domain Method of Different Mesh Spacings

    Masao KODAMA  Mitsuru KUNINAKA  

     
    LETTER-Antennas and Propagation

      Vol:
    E76-B No:3
      Page(s):
    315-317

    When we study time-domain electromagnetic fields, we frequently use the finite-difference time-domain (FD-TD) method. In this paper, we discuss errors of the FD-TD method and present the optimum mesh spacings in the FD-TD method when the three mesh spacings are different.

  • Optical Sampling of Electrical Signals in Poled Polymeric Media

    Makoto YAITA  Tadao NAGATSUMA  

     
    PAPER-Optical/Microwave Devices

      Vol:
    E76-C No:2
      Page(s):
    222-228

    This paper theoretically evaluates the external electro-optic (EO) sampling of high-speed electrical signals using poled polymers as materials for a proximity electric-field sensor. Based on the derivation of the half-wave voltage and the analysis of a static electric field coupled to the polymeric media placed over IC interconnections, invasiveness, voltage sensitivity, and spatial resolution have been discussed. The polymeric sensors have shown to be used in contact with the IC interconnections with negligibly small invasiveness, thus making polymeric sensors provide higher sensitivity and spatial resolution than inorganic crystals such as GaAs and KD*P.

  • Polarization Characteristics of Plane Waves Scattered by a Strip Grating with an Anisotropic Substrate

    Masamitsu ASAI  Jiro YAMAKITA  Shinnosuke SAWA  

     
    LETTER

      Vol:
    E75-A No:12
      Page(s):
    1765-1767

    In this paper, scattering waves by a strip grating with an anisotropic substrate for the incidence of inclined polarization are analyzed, and polarization characteristics of scatterd waves are calculated. For simplicity, the analysis is limitted to the case of normal incidence and a perfectly conducting strip grating is assumed.

  • An Improvement of the Equivalent Source Method for the Analysis of Scattering of a Plane Wave by a Conducting Cylinder with Edges

    Masao KODAMA  Kengo TAIRA  

     
    LETTER-Electromagnetic Theory

      Vol:
    E75-C No:9
      Page(s):
    1088-1092

    This letter proposes an improvement of the equivalent source method in order to give an accurate solution for the scattering of an electromagnetic plane wave by a conducting cylinder with edges.

  • Transient Electromagnetic Fields on a Conducting Sphere Excited by a Pulsed Plane Wave

    Akira ITOH  Toshio HOSONO  Yuuiti HIRAO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E75-C No:1
      Page(s):
    107-112

    We studied transient fields on a perfectly conducting sphere excited by a half sine pulse wave and examined the Poynting vectors, the energy densities and the energy velocities of the creeping waves. We used FILT (Fast Inversion of Laplace Transform) method for transient analysis. We compared the amplitudes of the creeping wave with that of steady state high frequency approximation obtained by the Watson transformation. The main results are: (1) We confirmed in the transient response that the pulse propagates clockwise and counterclockwise along the geodesic circumference. (2) In the transient electromagnetic field observed in the E-plane we can recognize creeping waves clearly. (3) The existence of creeping waves is not clear in the H-plane. (4) The pulse wave propagation on the sphere is seen more clearly from the Poynting vectors and the energy densities than the field components. (5) The energy velocity of the wave front is equal to the light velocity as should be. The energy velocity of the wave body becomes smaller with the passage of time. (6) The amplitude of the creeping wave for a beat pulse and the amplitude obtained by the Watson transform for mono spectrum agree in the order of relative error below 25%.

21-39hit(39hit)