摘要:

AbstractA technique for shaping the H‐plane pattern of a microstrip antenna using a passive unequally spaced planar array of printed strips as a superstrate layer is presented. By a proper choice of the number of strips, their widths, and their relative positions, quasiomnidirectional radiation patterns and radiation patterns with a dip on boresight have been realized. A two‐dimensional model for the analysis and design is presented. © 1992 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650050802

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

年代:1992

数据来源: WILEY

摘要:

AbstractSmall‐signal impedance measurements of GaAs/AlGaAs double‐barrier resonant tunneling heterostructures are analyzed in terms of equivalent circuits taking into account the quasibound‐state lifetime. The lifetime values extracted from experiments are in reasonable agreement with those deduced from calculation of quantum transmission probabilities. © 1992 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650050803

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

年代:1992

数据来源: WILEY

摘要:

AbstractWe report large increases in the harmonic components of the oscillation current waveforms for InP and GaAs TEDs by appropriate modulation of the device doping profile. The results are based on accurate drift‐diffusion simulations of Gunn‐diode structures. An unoptimized InP modulated‐impurity‐concentration transferred‐electron device demonstrated a 100% increase in second‐harmonic power generation as compared with its companion TED. © 1992 John Wil

ISSN:0895-2477    

DOI:10.1002/mop.4650050804

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

年代:1992

数据来源: WILEY

摘要:

AbstractFormulation in cylindrical coordinates for the reconstruction of the permittivity profiles using the moment method is presented. Angular spectral domain reconstruction is shown to be less sensitive to the ill‐posedness due to the noise in the scattered field than the configuration‐domain reconstruction. © 1992 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650050805

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

年代:1992

数据来源: WILEY

摘要:

AbstractAn expression for the effective relative dielectric permittivity of microstrip transmission lines, derived empirically for X‐band of frequency, is proposed for the computer‐aided design (CAD) of micro‐strips in higher microwave frequencies as well, by comparing with other CAD formulas. The accuracy and simplicity of the formula can demand priority in CAD technology. © 1992 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650050806

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

年代:1992

数据来源: WILEY

摘要:

AbstractIn this article a novel polarization‐modulated direct‐detection (PM‐DD) system is presented. The compatibility of the proposed system with an IM‐DD‐based optical network using doped fiber optical amplifiers and the possibility to implement efficient multilevel modulation make it promising for application in the future telecommunication environment. © 1992 John Wiley

ISSN:0895-2477    

DOI:10.1002/mop.4650050807

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

年代:1992

数据来源: WILEY

摘要:

AbstractIn this Letter a new finite‐element formulation, which has been found to provide no spurious mode, has been applied to superconducting microstrip lines. Very good agreement is exhibited with the spectral domain approach, modified by the surface impedance concept, in the simple case of a rectangular‐shape superconducting strip. This makes it possible, in the future, to use this finite‐element formulation for any shape of strip and for anisotropic material. © 1992 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650050808

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe gain, noise figure, and 1‐dB compression point of a commercially available GaAs amplifier were measured at cryogenic temperatures. The gain and noise figure characteristics were improved by decreasing temperature, while the 1‐dB compression point remained unchanged. Repeated temperature cycling had no adverse effect on amplifier performance. © 1992 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650050809

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

年代:1992

数据来源: WILEY

摘要:

AbstractA simple numerical method for extension of the bandwidth of six‐port reflectometers is proposed. The bandwidth extension is accomplished through calculations and not by six‐port design improvements. The method is tested on a microstrip integrated six‐port reflectometer and results for different loads are presented. © 1992 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650050810

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

年代:1992

数据来源: WILEY

摘要:

AbstractThis work shows that an accurate characterization of the nonlinear distortion of a GaAs MESFET, does not allow the common approach of splitting the Ids, (Vds, Vds) current in two voltage‐dependent nonlinear current sources, Gm(Vgs) and Gdx(Vds). It is shown that the cross terms of the IdsTaylor series expansion can give an important contribution to the MESFETs intermodulanon distortion behavior. A laboratory procedure for the complete characterization of that element is given. © 1992 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650050811

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

年代:1992

数据来源: WILEY