摘要:

AbstractInput‐integrated displays with a tablet and liquid‐crystal display (LCD) have been developed for computers. In the input‐integrated displays, parallax due to the thickness of a glass causes the difference between the positions of a pen and the displayed image.To eliminate the parallax problem, a fiber plate was used for the upper substrate of an LCD instead of a conventional glass plate and the newly developed LCD was evaluated.(1) It was found that when a fiber glass was used for the upper substrate of the LCD and liquid‐crystal material with a polarization characteristic (for example, one with dichromatic coloring matter which has anisotropic characteristics in the absorption of visible light in the long and short axes directions of liquid‐crystal molecules), the parallax observed when a glass plate was used almost disappeared.(2) The relationship among the pen position, glass plate thickness, and dot‐pitch of an LCD for conventional LCDs was obtained. Using the relationship, it was clarified that the disturbance due to the parallax could be

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780501

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn forming barium‐ferrite films by RF magnetron sputtering, a film structure is dependent on the substrate temperature (TS) when the Fe/Ba atomic ratio in the film is between 15 and 16, i.e., the c‐axis is oriented perpendicularly to the film surface, parallel to the film surface, or it is isotropic.The deposition temperature dependence of the crystalline orientation was investigated by evaluating the crystalline phase and structure during heat treatment. The film deposited at room temperature (TS=RT) contained a large amount of Fe2+prior to heat treatment, where Fe2+was randomly distributed. When this film was annealed, oxygen diffused into the film and ferrite was formed at low temperatures with a c‐axis parallel to the film surface. AsTSincreased, the amount of Fe2+in the film decreased and crystalline {110} FexO was formed. When this film was annealed, the temperature at which barium ferrite formation began increased and the c‐axis was isotropic. When a film was sputtered atTS= 750°C, {111} FexO was already formed in the as‐deposited film. When this film was annealed, FexO was transitionally transformed to Fe3O4, which dissolved into barium‐ferrite; the c‐axis was oriented in a direction perpendicular to th

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780502

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe concept of parametersA, B, andCof photo resist and outline of measuring theory and an instrument have been reported by Dill et al. in 1975. Since then, parametersA, B, andChave been used in simulation of profile or quality control of photoresist. In practice, however, a dedicated measuring instrument is hardly used and parameters are calculated from transmittance measured with a spectrophotometer instead.Dill et al. used a substrate of matched refractive index, but quartz substrate without matching its refractive index to photoresist usually is employed for convenience reasons. In this paper, experiments have been made to clarify the difference between Dill's authentic method and conventional method using a newly developed instrument (ABC‐Analyzer) and a conventional spectrophotometer.Light of broad band from an Xe‐Hg lamp was filtered through a narrow bandpass filter and exposed to a photoresist‐coated sample. Then temporal change of transmittance was measured and stored in a computer. ParametersA, B, andCwere determined automatically according to Dill's model using the transmittance data.Calculated parameters through two different procedures were compared. ParametersA, B, andCobtained by using the developed instrument were lower than those obtained by using a spectrophotometer. The difference comes from the difference in calculation method for transmittance. In other words, the transmittance measured with spectrophotometer is different from that based on Dill's definition.Furthermore, maximum differences in parametersAandBwere 5 and 45 percent, respectively, between those obtained from the samples using an unmatched quartz substrate and a refractive index matched substrate. This is caused by multiple interference between reflected light from the photoresist/substrate interface and that from the back side of the substrate. It was confirmed that it is important to minimize this effect in order to improve accuracy in measuringA, B,

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780503

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

年代:1995

数据来源: WILEY

摘要:

AbstractA detailed discussion of the preparation of a buried silica‐based optical waveguide by sputtering is presented. The morphological evolution of SiO2deposited on a ridge structure and smoothing the side wall are discussed on the basis of both experimental and computer simulation results. A new method of fabricating silica‐based optical waveguides with smooth side walls by radio‐frequency (rf) sputtering is described. A waveguide of either triangular or trapezium‐shaped cross section is fabricated on a prepared ridge in the substrate by rf sputtering. An analysis of the waveguide thus obtained of a triangular‐shaped cross section is made by the propagating beam method (PBM). The potential for application of the technique to optical waveguides is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780504

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

年代:1995

数据来源: WILEY

摘要:

AbstractFrequency stability of a 60‐GHz nonradiative dielectric (NRD) waveguide InP Gunn diode oscillator has been improved based on the phase‐locked‐loop technique. All the millimeter wave circuit elements needed, including the directional coupler, circulator, and so on, have been fabricated by using the NRD waveguide and a new approach has been introduced for harmonic mixer configuration by combining an NRD waveguide and a laterally shielded coplanar transmission line. By means of this approach, the millimeter wave circuit can be contained in a compact housing of 4 cm × 6 cm in area. The stability of the oscillation frequency of the fabricated Gunn oscillator was 2.1 × 10−10(13 Hz/60 GHz). Further, the phase noise was kept to a small value of ‐48 dBc/Hz. The present results confirm the applicability of the NRD waveguide in the

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780505

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

年代:1995

数据来源: WILEY

摘要:

AbstractV‐band and Ka‐band oscillators have been developed using monolithic microwave integrated circuits (MMICs). The active elements employed are AlGaAs/InGaAs heterojunction finite element transmitters (FETs) with a 0.15‐μm T‐shaped gate. The oscillators were designed with a series feedback circuit with capacitive stubs at the FET source side for generating negative resistance and a resonance circuit at the gate side.MMIC prototypes have power outputs of 4.5 dBm for a V‐band oscillator (fosc= 50.5 GHz) and 6.7 dBm for a Ka‐band oscillator (fosc= 30.6 GHz). The phase noise for the V‐band oscillator is ‐97 dBc/Hz (1 MHz off‐carrier), which is relatively small for a free

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780506

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe authors utilized monolithic microwave integrated circuits (MMIC) compatible devices, GaAs HBT and InP/InGaAs HBT, as photodetectors for a fiber‐optic/millimeter‐wave subcarrier link, and investigated the link loss characteristics, subcarrier‐to‐noise ratio (SNR) characteristics, and IM3 characteristics of the fiber‐optic millimeter‐wave subcarrier link, comparing them with those of the link using a pin photodiode. The link gain characteristics are compared with those of the links which use other MMIC compatible photodetectors (MSM and HEMT) and pin photodetectors (pin‐PD). It is found that for both the common emitter HBT link and the common‐base HBT link, good response and flat frequency characteristics can be seen over several gigahertz in the millimeter‐wave band.The SNR characteristics of the common emitter HBT link governs the noise characteristics of the optical/RF transducer in the low‐frequency region where there is internal gain. However, in the millimeter‐wave region (where there is no gain), it is dependent on the noise characteristics of the LNA connected after the HBT or in the common base HBT link. The input/output characteristics and IM3 characteristics of the HBT link are dependent on the power characteristics of the external optical modulator (EOM) when the optical power is less than ‐ 3 dBm.An optical/RF transducer combining an HBT photodetector, LNA, and horn antenna is designed. Using this optical/RF transducer, an optical fiber/millimeter‐wave radio link is designed and the FM video transmission characteristics are investigated experimentally. It is shown that this link was effective at waveleng

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780507

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

年代:1995

数据来源: WILEY

摘要:

AbstractWith respect to the vector finite element method for analysis of the electromagnetic waveguide, the numerical accuracy and the numerical efficiency are investigated for three types of variational expressions with which spurious‐free vector finite element analyses are possible. For the linear, isotropic, and lossless waveguide, these methods are compared with regard to the physical and mathematical properties and the electromagnetic field construction of the guided mode using vector‐shape functions represented by complete polynomials of identical form. Two of the variational expressions use different‐order shape functions for the two transverse components and the longitudinal component. Four types of computation methods can be constructed by selection of the electromagnetic field components. Another method uses the shape functions with identical orders in four transverse components.Numerical computations have been carried out for various waveguides. From the results of the computations, it is shown that the physical and mathematical properties of the two variational expressions using the three transverse and longitudinal components are equivalent and that the numerical accuracy of the propagation constant of each guided mode depends on the magnitude of the longitudinal field components used in an actual computation method unlike the method using four transverse components. By using the results, optimum selection of computation methods can be rea

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780508

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

年代:1995

数据来源: WILEY

摘要:

AbstractIt is shown theoretically and experimentally that a tunable oscillator without spurious oscillations can be obtained by using a magnetostatic forward‐volume wave resonator with wide strip transducers. First, the equivalent circuit of a rectangular resonator is presented and the unloadedQand the externalQare expressed in terms of the dimensions and the material constants of the resonator. By means of this expression, the condition is derived for selective excitation of the dominant mode and for suppression of the higher‐order modes. A 5‐GHz tunable oscillator using this resonator was fabricated. It was demonstrated that stable oscillation characteristics without spurious oscillations can be obt

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780509

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

年代:1995

数据来源: WILEY

摘要:

AbstractUsing a method for computer simulation, called particle simulation, this paper investigates in detail nonlinear characteristics (whose analytical treatment has been difficult to date) for a Cerenkov laser composed of a parallel plate waveguide loaded with a dielectric sheet and a planar relativistic electron beam focused with infinite magnetostatic field. The main results obtained here are summarized as follows. First, the growth of an electromagnetic wave is found to be due to energy transfer from the kinetic energy of an electron beam to the electromagnetic energy. Initially, the amplitude of an electromagnetic wave grows exponentially, and then nonlinearity gradually begins to dominate as electrons composing the electron beam are trapped in the electric field of the electromagnetic wave. In the final stage where most of the electrons are trapped, the amplitude of the electromagnetic wave gets saturated. In the early stage where the wave amplitude grows exponentially, the results obtained from particle simulation agree well with those obtained from linear analysis. In this paper, the efficiency of energy conversion from the electron beam to the electromagnetic wave is also estimated with the use of the energy carried by the electromagnetic wave at saturation.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780510

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

年代:1995

数据来源: WILEY