摘要:

AbstractThis paper describes the elimination of undesired mode suppression in a multiple‐device cylindrical cavity combiner caused by the effect of excitation of the desired power‐combining mode due to external signal injection. Mode analysis is carried out to derive the condition of undesired mode suppression and of sustaining the desired mode oscillation and to prove the capability of perfect combining of the output powers of the multiple‐device structure and the power of injected signal. Experiments with TM020‐mode cavity confirmed the

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760601

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

年代:1993

数据来源: WILEY

摘要:

AbstractAn analysis and numerical calculation of a leaky wave propagating in a magnetic waveguide with a resistive strip grating are presented. The analysis is formulated by a matrix. A characteristic equation of the waveguide is derived by applying the Galerkin method to a resistive boundary condition expressed by a Green function in a spectrum region for a magnetic material and also by a surface current density which is expanded in terms of functions.A numerical calculation is made for a leaky region where the effect of a surface resistance and magnetic loss are considered. A step function and a function with a singularity are used in expanding a surface current density. The validity of limiting expansion terms and the convergence of solutions are discussed for not only a propagation constant but also a root mean square error of the resistive boundary condition and a surface current density.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760602

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

年代:1993

数据来源: WILEY

摘要:

AbstractA finite‐element formulation is described and some numerical results are presented for excitation and transmission problems of magnetostatic forward volume wave. The governing equation for the vector potential is obtained through Maxwell's equations under the magnetostatic approximation.First, numerical results for radiation impedances of the magnetostatic wave agreed well with analytic solutions. Second, the reflection and transmission characteristics of the magnetostatic wave for a metal strip are analyzed. The reflection coefficient changes periodically with the width of the conductor and its periodicity agrees with a wavelength of the magnetostatic wave. In the case of a narrow strip, the interaction of evanescent waves becomes significant, resulting in a finite reflection coefficient when the width approaches zer

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760603

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper discusses the doping characteristics and the crystalline quality of GaInAsP/InP grown by a chemical beam epitaxy method important for realizing surface‐emitting lasers of long wavelengths. A good controllability of Be doping and very little degradation examined by photoluminescence are found in GaInAsP and InP for a wide range of Be dopants. The crystalline quality of a double heterostructure is improved by optimizing a growth condition. As a result, a minimum threshold current density of 5 kA/cm2is obtained for edge‐emitting lasers at a 1‐μm thick active layer.Under the optimized condition, a circular mesa‐cap surface‐emitter laser is fabricated. The minimum threshold current of 2.7 mA and the threshold current density 450 A/cm2are obtained at 77 K under the CW operation. A pulsed operation of an SE laser with GaInAsP/InP multilayer reflector is confirmed near room temperature. The applicability of the chemical beam epitaxy method for growing an SE laser is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760604

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

年代:1993

数据来源: WILEY

摘要:

AbstractRecently, the frequency range allocated to mobile communication has been extended to the gigahertz band (quasi‐microwave). The filters used in RF stages for this high‐frequency application require wide bandpass characteristics and must have ample attenuation outside this bandpass frequency.This paper describes the fine lithography technology necessary for fabricating surface acoustic wave devices used at the gigahertz band and also a low insertion loss surface acoustic‐wave (SAW) f

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760605

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe partial response (PR) system is believed to be an important scheme for signal processing in high‐density digital magnetic recording. This paper discusses the improvement in performance of the PR(1, 0m‐ 1, ‐1) system, which is one of the PR systems. With increasing recording density, a high‐frequency noise due to the compensation for a high‐frequency attenuation increases significantly and accordingly a signal‐to‐noise ratio (SNR) becomes lower, which is also tied to the inherent high‐frequency boost characteristics of PR(1, 0m‐ 1, ‐1).Also proposed is a new PR system and a signal‐detection method by which one can expect to improve the characteristics by using an intersymbol interference for a signal detection caused by suppressing a high‐frequency noise through a bandwidth limitation in PR(1, 0m‐ 1, ‐1). For the proposed system and the conventional PR(1, 0m‐ 1, ‐1) system, the SNR required to achieve a bit error rate of 10−8is obtained. It is confirmed that the proposed system provides a better perform

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760606

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

年代:1993

数据来源: WILEY

摘要:

AbstractNew methods to reduce the deformation failure of the polyimide‐insulated multilevel interconnection and nondestructive measuring method to estimate the failure are presented. Deformation failure of the interconnection was found to be detected more sensitively by electrically measuring yields of via‐chain patterns of the two‐level interconnection located around test chip corners than by observing the first‐level Al‐alloy line deformation directly. Reduction of the alloy line failure was examined by analyzing which part of the resin causes the shrinkage stress which in turn causes the alloy line failure. It is shown that both improving the package resin adhesion to the LSI chip and using a resin with a smaller thermal expansion coefficient were remarkably efficient in reducing the alloy line deformatio

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760607

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

年代:1993

数据来源: WILEY

摘要:

AbstractReactive ion etching (RIE) is known to alter electrical characteristics by creating a damaged layer on the surface of the etched substance. An Au/p‐Si Schottky diode was formed on a silicon surface which was etched by RIE using CF4gas. It was found that excess dc conductance and inductive susceptance were observed in the current voltage (I‐V) and the admittance frequency (Y‐f) characteristics under forward bias conditions, respectively. These results are explained by assuming the existence of deep‐level traps induced by RIE in the depletion region of the diode. Assuming a damage depth distribution of 10 nm, the experimental values of inductive susceptance are able to calculate by following parameters of the deep‐level traps induced by RIE;Er‐ Ev= 0.33 (eV) andNT= 1

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760608

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

年代:1993

数据来源: WILEY

摘要:

AbstractTo reduce the self‐heating effect and thermal noise in bridge‐type Josephson mixers, all‐NbN nanobridges with an Al “direct shunt” resistor were fabricated.This paper describes the millimeter‐wave response and mixing properties of the NbN(g)/Al nanobridge‐type Josephson mixers in the 100‐GHz frequency. The effective noise temperatureTNeffof the nanobridges was decreased to the bath temperature (liquid helium temperature, 4.2 K) by the Al “direct shunt” resistor and the millimeter‐wave induced steps were clearly observed at higher voltage (∼4 mV) than in the nanobridge without the Al “direct shunt” resistor.The millimeter‐wave current dependence of the height of the millimeter‐wave induced steps was analyzed quantitatively, taking into account the thermal noise in the RSCJ model. The simulated result agreed with the experimental result very well. The systematic decrease of the induced step height with an increase of millimeter‐wave current was explained as the increase of effective noise temperature due to absorption of millimeter‐wave power. In the 100‐GHz Josephson mixing experiment, a large IF power output was obtained at a voltage up to about 1.6 mV. The effective noise power NEP and conversion efficiency were abou

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760609

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe conventional tantalum electrolytic capacitor is made by anodically oxidizing sintered porous tantalum metal powder to form tantalum oxide film, followed by precipitating manganese dioxide by thermal decomposition of the tantalum oxide film soaked in manganese nitrate solution. The electrical conductivity of manganese dioxide is as low as 10−2to 10−1S/cm, and manganese dioxide is poor in its electrical property, in particular, the high‐frequency characteristic.In this paper, a precoating layer with a slightly higher resistance is used. The polypyrrole film is deposited by electrolytic polymerization using the precoating layer as the anode. It is found that the capacitor with polypyrrole formed by chemical oxidative polymerization has superior electrical properties compared to the capacitor formed by using manganese dioxide instead of a precoated layer. Using hydrogen peroxide as the oxidizer for chemical oxidative polymerization, polymerization of pyrrole can be achieved even inside the sintered body and the electrical conductivity and thermal stability of the polymer were excellent. The resultant capacitor has excellent electrical and temperature characteristics, its lifetime is long, and it can be surface‐

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760610

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

年代:1993

数据来源: WILEY