摘要:

AbstractWe show that a multiiris bandpass filter used in conjunction with a ring‐loaded slot bandstop filter in circular waveguide exhibits a considerably extended stop band with high localized attenuation. The results of an accurate analysis of the complete filter give exceptionally good agreement with measured data. © 1995 John Wiley&Sons. I

ISSN:0895-2477    

DOI:10.1002/mop.4650080502

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

年代:1995

数据来源: WILEY

摘要:

AbstractFabry‐Perot resonators and beam waveguides are used in quasioptical systems to refocus electromagnetic fields. These fields are described by Laguerre Gaussian or Hermite Gaussian quasi‐TEM mode families depending on whether the aperture is rectangular or circular. It is shown that certain lower‐order Laguerre Gaussian and Hermite Gaussian modes are identical. This has implications for the design of quasioptical systems for mode selection. © 1995 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650080503

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

年代:1995

数据来源: WILEY

摘要:

AbstractA new algorithm and system architecture for inverse filter generation using a coherent iterative optical processor is presented. This processor avoids the singularity problem usually faced in inverse filter generation. The algorithm convergence is analyzed and a convergence condition is derived. Computer simulation of the algorithm performance is presented, and the results confirm the theoretical predictions for the convergence. Two optical architectures for the implementation of this algorithm are also introduced, based on space‐ and time‐domain utilization. © 1995 John Wiley&Sons.

ISSN:0895-2477    

DOI:10.1002/mop.4650080504

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe characteristic impedance of the fundamental mode in a quadruple‐ridged waveguide is computed using the finite‐element method. The method is validated by comparison with available results for double‐ridged waveguides, and results for quadruple‐ridged waveguides are given for possible use in the design process of quadruple‐ridged waveguides. © 1995 John Wiley

ISSN:0895-2477    

DOI:10.1002/mop.4650080505

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

年代:1995

数据来源: WILEY

摘要:

AbstractA fast far‐field approximation (FAFFA) is developed to estimate the RCS of conducting scatterers. This method accounts for the interaction between subscatterers in two ways, depending on the electrical distance between the subscatterers. The interactions of subscatterers separated by a large electrical distance are computed in three stages: (1) aggregation, which computes the total field at a group center due to the subscatterers of the group; (2) translation, which translates the field from one group center to another; and (3) disaggregation, which distributes the field in a group center to each subscatterer in the group. Two strategies are employed to accelerate the computation in the above three stages. One is the use of far‐field approximation to simplify the computation in the translation stage; the other is the use of interpolation and smoothing techniques, which reduces the complexity of aggregation and disaggregation. The overall computational complexity for a matrix‐vector multiplication is of the order of N1.33, and the memory requirement is of order N. Numerical results show that this method can predict a RCS that is very close to exact solution, and that the method can be applied to objects with very large electrical sizes. © 1995 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650080506

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

年代:1995

数据来源: WILEY

摘要:

AbstractA novel Er‐doped fiber‐ring laser having less mode instability due to polarization fluctuation is proposed and experimentally investigated. The Er‐doped fiber is twisted to form a fiber‐ring laser. The right‐hand‐ and the left‐hand‐rotated circular waves preserved in the twisted fiber are exchanged by a fiber type ½ element placed in the fiber ring. This configuration can fix the separation between two polarization resonances (i.e., two ESOPs' resonances) and suppress the polarization‐mode instability. Both theory and experiment are presented conducted; the experiment his confirmed our design. In addition, the temperature effects on this fiber‐ring laser have been measured © 1995

ISSN:0895-2477    

DOI:10.1002/mop.4650080507

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

年代:1995

数据来源: WILEY

摘要:

AbstractExperimental techniques and data manipulation methods that allow highly accurate measurements of sheet resistivity values associated with thin films are presented. The procedure of microwave energy absorption is offered as a time‐efficient, noncontact, and nondestructive investigative means. © 1995 John Wiley&Sons. I

ISSN:0895-2477    

DOI:10.1002/mop.4650080508

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

年代:1995

数据来源: WILEY

摘要:

AbstractA recent study demonstrated the superior stability of quintic pseudosplines, when compared with usual oscillatory series expansions, for global interpolation of numerically defined reflector surfaces presenting critical behavior of their principal curvatures. Although interpolating functions with continuous derivatives up to second order are necessary for ray‐optical field evaluations, C‐class surface descriptions are sufficient when the antenna secondary field is calculated by integration of physical‐optics‐induced currents. In this connection, the applicability of cubic pseudosplines is explored via numerical comparison with previously obtained results from the implementation of the quintic ones. © 1995 John Wiley&S

ISSN:0895-2477    

DOI:10.1002/mop.4650080509

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe input impedance of a slot‐coupled cylindrical‐rectangular microstrip antenna is studied. Based on an equivalent circuit derived using the generalized transmission‐line model (GTLM) theory and taking into account the impedance transformations proposed previously for the analysis of a slot‐coupled microstrip antenna, the input impedance is readily calculated. Numerical results of the input impedance for some antenna parameters are presented and discussed © 1995 John Wiley&S

ISSN:0895-2477    

DOI:10.1002/mop.4650080510

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

年代:1995

数据来源: WILEY

摘要:

AbstractIt is shown that the equivalent edge currents (EEC) obtained in terms of the uniform geometrical theory of diffraction coefficients (EEC‐UTD) yield accurate values of the radiated far field in the boresight caustic region of a paraboloid. Failure of the equivalent edge current technique to provide the correct values for boresight region fields in a previous article is attributed to the reflector edge representation in that article. Radiation patterns computed by the EEC‐UTD method are found to blend well with the pattern obtained by the UTD technique. © 1995 John Wiley&Sons.

ISSN:0895-2477    

DOI:10.1002/mop.4650080511

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

年代:1995

数据来源: WILEY