摘要:

AbstractActive researches have been conducted recently on NRD lines which have low loss properties in millimeter wavebands and are suitable for integrated circuits. As an example for them, an asymmetrical structure has been proposed for an NRD guide which may be used for a leaky wave antenna. This paper analyzed such a guide for its three‐dimensional spatial‐time responses based on the Bergeron method. We made vectorial analyses on the instantaneous waveforms for all components of the electromagnetic fields and applied Fourier transform on the instantaneous waveforms in the spatial domain. From the wave number spectra thus obtained, we identified the existence of two leaky waveforms for individual modes. We obtained the propagation constant for each mode. Based on characteristic variations of the propagation constant for the dominant leaky mode as a function of the width of a longitudinal conducting plate and on the Poynting vectors, we showed that an NRD guide of such geometry becomes a leaky wave ante

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720701

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe interference‐type fiber‐optic gyroscope detects rotating angular velocity by means of interference between two optical signals traversing a fiber‐optic loop in opposite directions. In one method, the optical paths of two signals are completely equalized. In another method, the interference fringes obtained by adjustment of the lens location are used. This paper describes the second method. By means of a microoptic system using a bifocal lens, linear interference fringes are formed. After these fringes are read by a line scanner, the waveform is Fourier transformed so that the rotating angular velocity is derived from the obtained phase‐shift quantity. The results of the experiment indicate that the relationship between the input angular velocity and the output is linear over a broad range. A rotation of 0.02 to 182 deg/s was detected and the minimum output ripple at the time of detection was ±0.015 deg/s. The drift of temperature change was 0.03 deg/s per 0.01°C, and hence this method is sensitive to temperature

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720702

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

年代:1989

数据来源: WILEY

摘要:

AbstractThere have been no reports of papers which studied thoroughly and quantitatively the relation between the spatial resolution and the imaging parameters in the Fresnel transform technique. This paper describes the relation between the spatial resolution and the imaging parameters in the Fresnel transform technique. The experimental results are shown to be in good agreement with the theoretical estimations. Moreover, the theoretical consideration shows that a localized imaging is possible without using any localization technique if the scanning of the characteristic field is limited to a local region. An experimental result on the local imaging is presented. The results obtained in this paper show that the Fresnel transform technique has a great promise as a new NMR imaging method.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720703

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe newly proposed BiCMOS technology [4] is based on the idea of realizing an LSI with high‐speed and low‐power consumption properties, by combining the bipolar and CMOS technologies in the basic circuit. It was demonstrated in [4]that the designed performance can be realized for logic circuit. This paper reports on the application of the technique to the gate array, where the circuit is constructed by 1.3 μm Hi‐BiCMOS technology and the overall performance as LSI is evaluated experimentally. First, three kinds of master chips suited to the high‐speed processor such as a minicomputer are designed. Among those, a master chip was selected and developed, which includes a multiport RAM and is applicable to the arithmetic logic unit containing a register file. The internal RAM has a structure of 4 kbit and 3‐port, and the access time is less than 10 ns. A basic cell structure to construct the logic circuit by a combination of bipolar and CMOS technologies is devised. A 2‐input NAND gate with a typical delay of 0.45 ns was realized. This type of gate array will be useful in the devices such as those in minicomputer and communication systems, where a high‐speed operati

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720704

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

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper describes the fabrication and basic properties and optical property of a GaAs/AlGaAs surface‐emitting laser‐type optical threshold device. Initially, a GaAs/AlGa‐As surface‐emitting optical threshold device with a mesa cap ring electrode structure (active layer of 3 μm and absorption layer of 0.5 μm) was fabricated and it was found that the device had a threshold current of 430 mA under room temperature pulse operation. To confirm whether the absorption layer was effective, the slow pulse response was calculated theoretically. Then, it was confirmed that an asymmetrical optical pulse can be obtained experimentally. Then a nonlinear optical input‐output was obtained at the input optical density of abou

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720705

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

年代:1989

数据来源: WILEY

摘要:

AbstractIn transmission by image fiber, the image is blurred by mode coupling due to the crosstalk cores, which impairs the resolution. The analysis of such crosstalk phenomena by geometrical optics is very difficult, and wave theory must be employed. There are infinite modes excited in each element fiber of the image fiber. In case of low resolution, that is, when the period of spatial harmonics of the image is small compared with the size of element fiber, higher modes are excited in the fiber.In this paper, the effects of higher modes upon image transmission characteristics of one‐dimensional image fiber are analyzed using vector wave theory. Since the crosstalk characteristics vary widely with wavelength, and various wavelength components are involved in the input image, the analysis of wavelength dependency of the crosstalk is important. By the numerical method, various characteristics are analyzed, and improvement methods are also discusse

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720706

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

年代:1989

数据来源: WILEY

摘要:

AbstractA solution based on the finite‐element method (FEM) is presented for the analysis of SH‐type surface acoustic wave gratings. Although the FEM has already been applied to the discontinuities in elastic waveguides for SH‐type modes, only the isotropic substrate has been treated. Also, it is difficult to apply the FEM directly to many discontinuities such as grating reflectors due to excessive computation time and computer memory requirements.This paper presents a numerical approach to the analysis of SH‐type surface acoustic wave gratings on anisotropic substrates. To apply the FEM directly to many discontinuities, the substructure method is introduced. As a result, mutual interaction between surface waves and bulk waves is automatically taken into account over the entire discontinuity region. To show the validity and usefulness of this approach, examples are computed for various gratings on PZT‐4, 41°Y‐XLiNbO3, and 36°Y‐XL

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720707

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

年代:1989

数据来源: WILEY

摘要:

AbstractBy means of approximate charge distribution on an interdigital transducer (IDT), it is shown that not only the electromechanical coupling coefficientk2and the radiation conductance for the surface acoustic wave (SAW), but also the radiation conductance due to the radiation of a bulk wave from an IDT can be obtained from the effective permittivity in an analytic, though approximate, form. Next, a simple method is proposed in estimating the spurious level of the bulk wave in an SAW device by using the radiation conductances for the SAW and the bulk wave. In general, the spurious level due to the bulk wave often depends on the geometric shape. The maximum value can readily be computed by the present evaluation method. The analysis results agreed well with the experimental data on Li2B4O7and LiTaO3used as SAW device substrates. It is also shown that a program for deriving the effective permittivity can be developed by making use of the computer program for the SAW velocity calculations.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720708

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

年代:1989

数据来源: WILEY

摘要:

AbstractUniform, stable drop generation is the key technology for continuous ink jet printing. Previously, the method to produce the standing wave driven by the high polymer piezoelectric transducer had been utilized for acoustic excitation. However, the characteristics varied from assembly to assembly and were unstable to the environmental changes. As a new alternative approach, the Traveling‐Wave Drop Generator (TWDG) was developed in which the acoustic wave is generated in one end, and then travels to the other end of the jet array. The characteristic results showed that this generator could fully solve the forementioned problems, and it has a simplified structur

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720709

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

年代:1989

数据来源: WILEY

摘要:

AbstractFrom the viewpoints of contact reliability for small‐sized contact components, growth processes of the oxide film on the Cu contact surface were analyzed by studying the film thickness and formation of films. This analysis of the film was conducted in detail by ellipsometry which scarcely applied to the contact phenomena, in combination with an electrochemical reduction method. Moreover, the effect of the growth of the film on the contact resistance property was studied. As a result, in the oxidation by heating in air, Cu2O film grows mainly at the initial stage of the film growth. As the film grows around 1000 Å, CuO appears on the surface of Cu2O.In this stage, the contact resistance increases sharply and contact failure occurs. Furthermore, it was found that the velocity of growth of the film is slowed which corresponds Co each stage of the oxidation: the initial, the middle, and the latter stage. By application of ellipsometry to the analysis of the contact surface, the measurement of the film thickness together with the possibility of discrimination for the formation of the film by using changes of the optical constants of the film were clarifi

ISSN:8756-663X    

DOI:10.1002/ecjb.4420720710

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

年代:1989

数据来源: WILEY