摘要:

AbstractThe problem of electromagnetic wave propagation in tunnels with branches and bends, such as those that would be found in an underground shopping center, has been analyzed with the finite‐volume/time‐domain (FV‐TD) method. The FVTD method is based on difference equations discretized by a volume integration of Maxwell's equations for arbitrarily small polygonal cells. In this method, the medium constants within the infinitesimal cell are constant and their values differ from cell to cell. Therefore, this method can easily handle the boundary value problem with an arbitrary shape that contains inhomogeneous media. In homogeneous media, the FVTD method and the finite‐difference/time‐domain (FDTD) method are equivalent in the Descartes coordinate system. In one application of the FVTD method, numerical calculations were made for tunnel structures that are typically difficult to analyze. To prove the usefulness of the FVTD method, a microwave simulation experiment was done. The numerical and experimental values were shown to a

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790901

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThis paper proposes an analysis method of diffracted waves in isotropic chiral gratings with periodicity in an arbitrary three‐dimensional direction. In this method, the spatial harmonic expansion method applied to the analysis of anisotropic dielectric gratings is extended. By Fourier transform of the periodicity of the chiral admittance, a systematic matrix form is used for rigorous formulation. In the numerical examples given here, calculations are carried out for the density modulated grating in which the relative dielectric constant and the chiral admittance distributions are varied sinusoidally. A coupling between the circularly polarized diffracted waves due to the Bragg condition and an anomalous diffraction phenomenon due to the chiralty of the medium are presented. This coupling is not observed in the case of nonchiral isotropic dielectric grating

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790902

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractA method to estimate the refractive index profile of an optical waveguide exists in which the optical intensity distribution of the only one propagation mode is used. Since this method requires only a microscope and a television camera, setup is extremely simple and inexpensive, thereby making the method practical. The differential processing method and the inverse analysis method have been proposed as methods to use the optical intensity distribution of only one propagation mode. The mechanisms of these methods that use the optical intensity distribution are presented in detail here. As a consequence, a new method that overcomes the difficulties in the previous methods, to be called Improved Inverse Analysis Method with Fewer Parameters, is proposed. Further, by using this proposed method, the index profiles of the step‐index type optical fiber and the buried optical waveguide can be estimated in order for validity of the method to be studie

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790903

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractIn this paper, the scattering coefficients of the E‐plane right‐angle bend, T junction, and cross junction in a rectangular waveguide are derived by the mode‐matching method [12]. In this method, the electromagnetic fields in the junction section formed by a sectoral or a circular region are matched to those in the waveguide region. Since the T junction and the cross junction can be constructed with several right‐angle bends, their scattering coefficient solutions can be unified in the same form as those of the right‐angle bend. The expressions for these solutions are simple, convenient, and the numerical values are highly accurate over a wide frequency range. By using these values, the details of the scattering characteristics of the dominant and higher‐order modes at the junction can be obtained. The resonance phenomena of the dominant and the higher‐order modes in the high‐frequency range are important for the study of the fundamental characteristics of the mic

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790904

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractWithin the tube of the cathode ray tube (CRT), a magnetic shield is formed. This shield is made of soft magnetic materials and includes the inner magnetic shield (IMS), frame, and aperture grill as a color selection mechanism. By means of this shield, the mislanding drift by the terrestrial magnetic field is controlled and each magnetic material in the magnetic shield, in general, eliminates magnetization by ac attenuation magnetic field at the time of kick‐off. This ac demagnetization process is considered to be an anhysteretic magnetization process; and, to analyze its characteristic, the magnetization process is simulated. To verify the results, a method is conceived for measurement of the anhysteretic magnetization.The anhysteretic magnetization of various shielding materials is measured. (In practice, the magnetic flux density was measured.) It is shown that the measured results agree well with the prediction. It is shown also that the effective permeability of the magnetic shielding materials after ac demagnetization unknown to date can be expressed quantitatively as an anhysteretic permeability. Further, the relationship between the anhysteretic permeability of the IMS and the terrestrial magnetic field is studied by simulation and experiments. Finally, it is shown that the anhysteretic permeability is a fundamental magnetic parameter of the drift of the terrestrial magnetic fiel

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790905

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractIn the electrolytic capacitor, the tunnel pits of the anodic foil provide most of the overall capacitance and it is important from the viewpoint of analyzing the essential characteristics of the capacitor to investigate the mechanism inside the tunnel pits. The purpose of this paper is to promote such an understanding and to present a new analysis of the principle and the actual situation of the tunnel pits. First, the internal state of the pit in the normal operation is assumed. Then, a new parallel distributedC‐Requivalent circuit is presented based on the path resistance concept related to the existence probability of the movable charge. By analyzing the characteristics of the equivalent circuit, the characteristics inside the pit can be estimated.It is shown that the path branch (1) of the charge moving between the infinitesimal oxide layer adjacent to the deepest part of the pit and the pit entrance has tan δ, which is approximately 1.5 times the reference * tan δ of the pit. It is proposed that the relation between tan δ, and the tan δ specification anticipated in the pit should be used in the decision of the limitf(frequency). The equation for the forementioned decision is simple in that it is composed of basic factors but meets most of the requirements, and it is expected to be useful in estimating the internal state.Next, the basic equation for the internal impedanceZof the pit is derived in a reasonable way, in comparison to the known typical expression forZ.It is shown that the existing expression has a complicated error. The relation between the decision expression for the limitfand the new expression forZis clarified, and they are shown to complement each other. In other words, the framework for the analysis of the inside of the pit is now completed. The result also provides a new knowledge as to the analysis of the general distributed ci

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790906

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe interfacial solid‐phase reactions taking place in the Al/Al3Zr/Zr/Si contact systems have been investigated to evaluate the effectiveness of Al3Zr/Zr bilayered films as a diffusion barrier in Al‐metallization technology. The interposition of an intermediate Al3Zr layer can successfully suppress the possible spontaneous rections between the Al and Zr layers because nearly‐minimum free energy states are realized at interfaces of both Al/Al3Zr and Al3Zr/Zr. It is revealed that the present system tolerates heat treatment at temperatures of up to 470°C and the formation of a Zr‐silicide layer is observed at the Zr/Si interface after heat treatment in the temperature range of 450

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790907

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe post‐exposure bake (PEB) characteristics of a photoresist can be examined with a method that estimates the diffusion length of a photoactive compound (PAC) in the photoresist PEB process. Diffusion lengths are estimated with development rate measurement equipment using PEB conditions at temperatures of 50°C, 100°C, 110°C, and 120°. An ultrahigh‐resolution i‐line photoresist THMR‐iP3000 is used in the research. The obtained values are input into a photolithography simulator PROLITH/2 to calculate photoresist profiles. Using a 365‐nm wavelength, 0.5 NA, and 0.6‐coherence factor conditions, resist profiles for a 0.4‐μm line space feature are calculated with varied focus. The simulated results are compared with SEM observations to evaluate the validity of the estimation method; they are found to be substantially consistent with experimental results, thus confirming the vali

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790908

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe formation process as well as the characteristics of a surface oxidized layer formed on Al‐Y alloy films are examined. Al in the alloy forms a thin Al2O3layer due to more oxidation at the alloy surface. In an alloy of Al‐rich composition, if the Al2O3surface layer (which is comparable to that formed on pure Al) is formed, the layer maintains its ability to be a self‐passivating oxide layer. In those alloys that form an unduly thin Al2O3surface layer, introduction of oxygen from the ambient environment cannot be curtailed. As a result, oxidation proceeds and the formation of Y2O3and reduced Al is observed within the oxide layer. In the oxidized layer, the oxidation state of the lesser amount of oxide is affected by that of the greater amount oxide; this reflects a shift in binding energy of the XPS spectra for the minor element. It is shown that the formation process of the alloy is dominated by the differences of ionization potential, an element affinity, formation heat, a diffusing species and the transport behavior of cations and/or a

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790909

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractA contactless readable medium using a combination of amorphous magnetostrictive ribbon and semihard magnetic material has been investigated. The data are recorded onto the semihard magnetic material, whereas the readout utilizes the fact that the appearance of higher‐order resonant peaks of the magnetostrictive vibration of the ribbon by the application of an ac magnetic field can be controlled by the leakage magnetic flux from the semihard material.The effect of the leakage magnetic flux generated during longitudinal magnetic recording on the semihard magnetic material by MIG head as a localized bias magnetic field has been examined.The results of using a direct magnetic field from a pair of single‐pole heads as a localized bias magnetic field has been further examined; determination of wavelength recorded on the semihard magnetic material also has been done. As a result of observing the power spectrum in the ac magnetic field of the medium combining amorphous magnetostrictive ribbon (Metglas 2826 MB) of 80 × 5 × 0.04 mm3and semihard magnetic material (CuNiFe alloy) of 100 × 10 × 0.2 mm3, the resonant peak of the amorphous magnetostrictive ribbon has been almost individually detected from the second to fifth orders corresponding to the recorded magnetization p

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790910

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY