摘要:

AbstractThe concept of diversity transmission was applied to the optical soliton communication system. For system configuration, two transmission lines are used and an optical coupler is inserted along the way. The configuration is resistant to Gordon‐Haus jitter caused mainly by the amplification spontaneous emission (ASE) noise from the optical amplifier. Using the present method, it shows that the timing jitter can be stabilized if the perturbation of the jitter is less than the width of the soliton pulse. It is also shown that the effect of the random phase variations received along the optical fiber transmission with a large effect of perturbation (such as the nonuniform distribution of the index of refraction) can be compensated. The paired soliton transmission system is the one for which a high transmission stability can be expected even in a transmission path with a large effect of the random jitte

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790301

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

年代:1996

数据来源: WILEY

摘要:

AbstractDispersive fibers are fabricated in which the refractive index dispersions of the core and cladding cross at a certain wavelength. The core and cladding were made of different types of optical glasses. To pass a long wavelength light (to suppress short wavelength light), the refractive index of the core was chosen to be lower than that of the cladding in the short wavelength region. In the fabricated dispersive fibers, no waveguide mode was observed in the short wavelength region, indicating that the fibers play the role of a long wavelength pass filter. To evaluate the fibers as an optical filter, the transmission loss and insertion loss were investigated and it was found that the pass wavelength region could be controlled by changing the curvature of the fibers.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790302

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

年代:1996

数据来源: WILEY

摘要:

AbstractIn this paper, a low‐profile filter using an open circular dual‐mode dielectric resonator is proposed as a filter for a mobile communication base station. The basic configuration of the dielectric resonator consists of two dielectric disks with electrodes on both sides stacked in the axial direction; they are installed in a shielded cavity. The doubly degenerate fundamental mode has an electric field parallel to the axial direction of the dielectric disks, and the resonator can be made low profile without significantly changing the resonant frequency. The equivalent circuit of the dual‐mode resonator is given in terms of a ring‐shaped transmission line with its electric length of 2°. The equivalent circuit of the multistage filter using this resonant circuit can be designed by the Chebyshev filter design method. A six‐stage filter with the center frequency of 985 MHz and the passband width of 10 MHz was fabricated. The results agreed well with those of the simulation. The insertion loss at the center frequency is 1.3 dB, and the external dimensions are 158 × 5

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790303

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

年代:1996

数据来源: WILEY

摘要:

AbstractIn‐plane vibration in rectangular plates of piezoelectric ceramics which were polarized along the direction of plate thickness was investigated by two‐dimensional transient analysis. In this analysis, it was assumed that both the top and bottom surfaces of the rectangular ceramic plates were electroded entirely and the four‐edge surfaces were not constrained. The spatial network method was employed for numerical analyses. Transient responses were evaluated numerically first for the cases where stepwise input voltages were applied to square plates.In‐plane wave motion and displacements of free edges were calculated. The results indicate the following behaviors: 1) a longitudinal wave is created at the free edge and propagates along the surface of the plate; 2) a part of the longitudinal wave is transformed to a shear wave at a free boundary parallel to the direction of the wave propagation; and 3) these two waves experience repeated reflections at the free boundaries and thus form a complicated vibration. Transient responses of a rectangular ceramic plate were analyzed next. Prior to the analysis, the vibratory behaviors of the rectangular plate were predicted approximately based on the results for the square plate. The detailed numerical analyses performed could confirm the validity of the pred

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790304

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

年代:1996

数据来源: WILEY

摘要:

AbstractAs a quartz resonator needed for miniaturizing electronic devices, a rectangular AT‐cut quartz resonator sealed in a cylindrical capsule has been developed and manufactured. It was found that the anomalous characteristics of the resonator at a low‐drive level have something to prevent starting oscillation. The drive level characteristics of the rectangular AT‐cut quartz resonator sealed in a cylindrical capsule have not been clarified to date. These characteristics are obtained from the low‐drive level to the high‐drive level. Among these characteristics, the anomalous phenomena at the low‐drive level (LDL) have been studied experimentally and theoretically. It was found that the anomalous phenomena are caused by the unwanted vibration of the structure other than the resonator plate itself. The frequency of the unwanted vibration depends strongly on the drive level. At the drive level that makes the frequency identical to that of the main resonance, an anomaly occurs in which the frequency and CI jump substantially. The manner of this jump can be calculated by assuming that the unwanted vibration is proportional to the current squared and the coefficient is large. The analysis shows a good agreement with the experimental result. In regard to the unwanted vibration found in the present experiment, it is assumed that the coefficient dependent on the square of the current of the unwanted vibration is negative and that the unwanted vibration is significantly originated in the structures attached to the quartz plate (such as electrodes, support member, mounting material

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790305

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

年代:1996

数据来源: WILEY

摘要:

AbstractIt was found that a surface acoustic wave microsensor is highly sensitive in detecting the physical and chemical changes of the medium on the vibrating surface in real time. Hence, microsensors are used in many applications. There are already several types of surface acoustic wave microsensors with their differences based on vibration and wave modes. New types of sensors are proposed herein and new findings and new applications are reported. The present level of development of surface acoustic wave microsensors is described and these sensors are compared, discussed, and evaluated.Fundamental characteristics are then presented for the shear‐surface acoustic wave (SH‐SAW) microsensors using a 36° rotated Y‐plate X‐propagation LiTaO3studied by the authors. It is shown that this sensor has many applications. Further, if several SH‐SAW sensors with different frequencies are used, a high recognition rate can be obtained even for liquid samples that cannot be recognized by human perception. The example used here is 13 types

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790306

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

年代:1996

数据来源: WILEY

摘要:

AbstractTo investigate the photoresist development characteristics, a development parameter extracting system for photoresists has been developed utilizing a development rate monitoring system and an exposure parameter measuring system for photoresists. This system is used to obtain the development parameters of a super‐high resolution i‐line photoresist, PFR‐ix500EL (Japan Synthetic Rubber Co., Ltd.), using the development rate equations by Dill, Kim, and Mack. At the same time, the dependence of the simulated profiles on the development rate equations is investigated. Focus latitude for achieving 0.5 μm lines and spaces under the conditions of exposure wavelength of 365 nm, NA = 0.5, and s̀ = 0.6 is evaluated; the simulated and experimental results are compared. It is found that when Mack's equation is used to simulate the development rate, the simulated and experimental results are in good ag

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790307

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

年代:1996

数据来源: WILEY

摘要:

AbstractIn order to improve the high‐temperature reliability of a silicon accelerometer, an accelerometer was fabricated using an SOI substrate and its temperature dependence was compared with that of conventional silicon accelerometers. In addition, the authors attempted to detect the three‐dimensional components of the acceleration vector using a new theoretical principle. The new theoretical principle was validated, and accelerometer design was carried out using a program for structure analysis, ANSYS, which is based on the finite element method (FEM). It was found that, in the accelerometer fabricated using an SOI substrate, the offset voltage and sensitivity at temperatures higher than 200 °C were superior to those in the conventional pn junction device. It was also found that the new device could detect acceleration even at 410°C. Using the new device, the acceleration components in the three directions were accurately measured and the sensitivity for the other axis was suppressed to less than 5.7 percent. The frequency characteristic of the new sensor was in agreement with the theoretical results. Because of high‐temperature operation and detectability of the three directional components of acceleration, this new accelerometer will be much more wide

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790308

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe dynamic characteristics of the capacitance of liquid‐crystal display (LCD) pixel constituting the active matrix LCD device using amorphous thin film transistors (TFTs) have been analyzed; an electrically equivalent circuit model is proposed based on the obtained results. The model consists of nonlinear resistors and dynamic elements such as capacitors or inductors and can represent the voltage and time dependence of the capacitance value in the LCD pixel. The proposed model is incorporated into the circuit simulator SPICE as a built‐in mo

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790309

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

年代:1996

数据来源: WILEY

摘要:

AbstractTo replace the conventional ion‐sensitive field‐effect transistor (ISFET) ion sensor, an ion‐sensing method using crown ether was developed. In this method, the alkaline metal ions (Na+and K+ions) were detected by the ac potential difference. Crown ether shows selectivity toward alkaline metal ions, forming complexes.To investigate the selective characteristics of crown ethers using the ac potential difference, three types of crown ethers (18C6, 15C5, and 12C4) were used. The solvents used were water, methyl alcohol, acetone, propylene‐carbonate (PC), and dimethyl‐formamide (DMF). Specifically, chlorides (NaCl, KCl, and CsCl) were dissolved in the solvent containing crown ether and the sedimentation potential was measured using a sedimentation‐potential measurement system.When 18C6 was used, the highest sedimentation potential of KCl was observed if PC was chosen for the solvent. When 15C5 was used, the highest sedimentation potential of NaCl was observed if methyl alcohol was used for the solvent. It was confirmed that in order to distinguish K+ and Na+ ions from other ions, PC containing 18C6 and methyl alcohol containing 15C5 should be used, r

ISSN:8756-663X    

DOI:10.1002/ecjb.4420790310

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

年代:1996

数据来源: WILEY