摘要:

AbstractThis contribution presents a new technique for implementing vertical currents into the spectral‐domain approach. Previously published methods require a drastic increase of spatial resolution and thus CPU time when adding vertical elements. Our technique avoids this by using partial Galerkin solutions without vertical expansion functions and by applying continuity conditions. © 1994 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650070902

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

年代:1994

数据来源: WILEY

摘要:

AbstractA simple theory and a model for the GaAs heterojunction bipolar transistor's (HBT's) high‐frequency performance under optical illumination are described. It is assumed that the major contribution to the photocurrent in the HBT is due to the photovoltaic effect in the base‐collector depletion region. Estimations using PSPICE circuit simulator show photoresponse cutoff frequencies of several tens of gigahertz when some HBT parameters are adequately designed. © 1994 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650070903

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

年代:1994

数据来源: WILEY

摘要:

AbstractIn this article we present a novel approach to deriving local boundary conditions that can be employed in conjunction with the finite‐difference and finite‐element methods (FD/FEM) to solve electromagnetic scattering and radiation problems. The key step in this approach is to derive linear relationships that link the values of the field at the boundary grid points to those at the neighboring points. These linear relationships are satisfied, to within a certain tolerance, by all of the outgoing wave components. They can thus be used in lieu of the FD/FEM equations employing the usual absorbing boundary conditions for the boundary points. The present approach not only provides a simple way to derive an accurate boundary condition for mesh truncation, but also preserves the banded structure of the FD/FEM matrices. © 1994 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650070904

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe beam‐propagation method is used to analyze the insertion losses of S‐shaped dielectric slab bends. Two circular arcs, sine‐generated, and cosine‐generated curves are compared and discussed. Calculation shows that the S‐shaped bend composed of two circular arcs with constant curvature gives excellent performance, provided the core is properly offset. © 1994 John Wiley

ISSN:0895-2477    

DOI:10.1002/mop.4650070905

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

年代:1994

数据来源: WILEY

摘要:

AbstractA tangential vector finite‐element formulation is implemented to deal with arbitrary cross section and metallic strip shape. Classical planar transmission lines as well as nonconventional cross‐section waveguides such as the new microshield line are treated. Effects on propagation characteristics for these lines are studied when the metallization shape is approximated by a lossy trapezoid area. © 1994 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650070906

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

年代:1994

数据来源: WILEY

摘要:

AbstractThis article presents results from a study on the effect of data sampling rate for earth‐space propagation experiments. Data taken from the Olympus 30‐GHz satellite beacon signal at Blacksburg, VA were sampled at 10 Hz in real time and then postprocessed to obtain effective sampling rates down to 0.1 Hz. Both event and statistical data are presented. © 1994 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650070907

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

年代:1994

数据来源: WILEY

摘要:

AbstractA new way of feeding an SSFIP antenna to obtain two orthogonal linear or two circular (RHCP/LHCP) polarizations is presented. The advantages of the method are its simplicity, a perfect symmetry of the structure and of the pattern, and an excellent decoupling between input ports. The enhanced element retains the desirable properties of conventional SSFIP elements: wide bandwidth, low cost, robustness, and low thickness and weight. © 1994 John Wiley&Sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650070908

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

年代:1994

数据来源: WILEY

摘要:

AbstractChemical etching and deposition techniques have been used to fabricate longitudinal slots for a linear slotted waveguide array operating at 15 GHz. A comparison between computed and measured data for the antenna radiation pattern demonstrates the success of this low‐cost and accurate fabrication method. © 1994 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650070909

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe frequency dependence of the RCS of an arbitrarily shaped simple scatterer is given, based on which model measurement of RCS can be made with testing equipment unchanged, even though the size of the model is sometimes scaled down with respect to that of the prototype. © 1994 John Wiley&Sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650070910

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

年代:1994

数据来源: WILEY

摘要:

AbstractStructures having symmetrically centered microstrip lines enclosed in a metallic waveguide are analyzed by the finite‐element method. Single and combined shielding effects on the microstrip effective dielectric constant due to a top cover and two side walls are investigated. A finite‐element computer program has been written in Fortran for a supercomputer to obtain very accurate numerical results by means of the solution of a very large system of linear equations. In addition, a new set of accurate empirical equations adequate for CAD to take both effects into account has been developed. Results are compared with other numerical and empirical methods, and discussions are also presented. © 1994 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650070911

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

年代:1994

数据来源: WILEY