摘要:

AbstractInterdigitated photoconductive detectors with 5‐μm geometry have been fabricated on HEMT material and their optical response characteristics at 820 nm have been examined at DC and in the frequency range of 2‐8 GHz. These have been compared with characteristics of similar 1‐μm devices on MESFET material. The shapes of the frequency responses were found to differ, but the useful bandwidth of both types of devices was found to be

ISSN:0895-2477    

DOI:10.1002/mop.4650020102

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

年代:1989

数据来源: WILEY

摘要:

AbstractIn this paper we present a finite‐element analysis of waveguides that are inhomogeneously filled with an anisotropic material, which may be either dielectric or magnetic type. The problem is formulated by using the transverse magnetic or electric field components, respectively, for anisotropic dielectric and magnetic materials. The formulation employed eliminates the spurious and nonphysical modes by analytically satisfying the divergence relations and achieves a reduction in the computer storage requirement as well. Numerical results are found to exhibit good agreement with the available dat

ISSN:0895-2477    

DOI:10.1002/mop.4650020103

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

年代:1989

数据来源: WILEY

摘要:

AbstractDispersion characteristics and modal currents of an open microstrip line are computed using the mixed‐potential electric field integral equation. Particular attention is given to the correct determination of the radiating, leaky‐wave mo

ISSN:0895-2477    

DOI:10.1002/mop.4650020104

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe attenuation coefficient of the guided mode supported by a metal‐clad planar dielectric waveguide is deduced by a perturbation technique that is commonly used for metallic waveguides for both the transverse electric and the transverse magnetic mode

ISSN:0895-2477    

DOI:10.1002/mop.4650020105

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

年代:1989

数据来源: WILEY

摘要:

AbstractWe present analytical expressions for the signal and the amplified spontaneous emission (ASE) noise in a coherent optical system using Raman amplification. The results show that the signal spectrum is unaffected by the amplifier and the ASE noise can be thought of as additive white Gaussian noise within the signal bandwidth.

ISSN:0895-2477    

DOI:10.1002/mop.4650020106

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

年代:1989

数据来源: WILEY

摘要:

AbstractThis article describes a technique by which a laser diode coupled with an external cavity is used in an interferometric system resulting in a direct envelope modulation of the optical carrier. The laser output is fed to a Mach‐Zehnder interferometer in which the time delay associated with the path imbalance is adjusted to half the time period Tmof the modulating sawtooth current. The two signals are heterodyned to simulate an envelope modulated optical signa

ISSN:0895-2477    

DOI:10.1002/mop.4650020107

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

年代:1989

数据来源: WILEY

摘要:

AbstractA joint transform hybrid optical correlator as applied to binary phase only filtering for pattern recognition is proposed. The interference fringes of the joint Fourier transformation, due to the reference and the input targets, are captured by a CCD camera feeding into a microcomputer for binarization. A binarized phase only filter, in principle, can be written onto a spatial light modulator (SLM). By simple coherent illumination of SLM, correlation operation of the reference and the input targets can be obtained. A computer simulation for the target embedded in an additive Gaussian noise is provided.

ISSN:0895-2477    

DOI:10.1002/mop.4650020108

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe use of lumped elements in microwave monolithic circuits (MMICs) is an essential feature allowing substantial reduction of GaAs substrate and reduced area cost when compared with conventional distributed microwave designs. The development of low loss passive circuit elements is therefore critical for the realisation of space conservative and efficient monolithic circuits.This paper discusses the properties of a series of lumped element designs that exhibit the same functional behaviour as the distributed quarter‐wavelength quadrature branchline coupler and presents a set of closed equations for their desig

ISSN:0895-2477    

DOI:10.1002/mop.4650020109

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

年代:1989

数据来源: WILEY

摘要:

AbstractAccording to the model of equivalent dipoles for active molecules, the analysis of inelastic EM scattering by active molecules embedded in a sphere is given by the method of dyadic Green's functions at first and then, based on the theory of elastic multiple scattering by randomly distributed spherical scatterers which we have developed recently, a new theory for analysis of inelastic multiple scattering by active molecules embedded in randomly distributed spherical scatterers also is developed.

ISSN:0895-2477    

DOI:10.1002/mop.4650020110

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

年代:1989

数据来源: WILEY

摘要:

AbstractA spectral inverse technique, applying the moment‐method procedure with a series expansion for the induced field in each enlarged cell, is suggested to reconstruct permittivity profiles of inhomogeneous dielectric objects. In particular, averaging the reconstructed permittivity distribution over each cell with a weighting function becomes an effective tool to regularize the error arising from a Gaussian random noise of the scattered fiel

ISSN:0895-2477    

DOI:10.1002/mop.4650020111

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

年代:1989

数据来源: WILEY