摘要:

AbstractThe first demonstration of a new S‐shaped single‐mode fiber loop resonator is presented. The S‐shaped fiber loop resonator is made with a nonplanar 3 × 3 fiber directional coupler and two fiber delay lines. Expressions for the circulating (resonant) fields and the transmitted and reflected output fields are derived. Theoretical and experimental results show that this fiber loop resonator may have potential applications as a spectral filter and a closely spaced two‐channel wavelength division multi/demul

ISSN:0895-2477    

DOI:10.1002/mop.4650061502

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

年代:1993

数据来源: WILEY

摘要:

AbstractOptical pulses at a repetition frequency of 1 GHz from a gainswitched InGaAsP distributed‐feedback laser diode at 1.3 μm are optically sampled with compressed pulses from a mode‐locked erbium‐doped fiber laser amplifier. High signal‐to‐noise ratios down to 21‐μW average laser‐diode power with temporal resolutions close to the sampling pulse duration of 4 ps are achieved. The sampled waveform is displayed at a repetition rate of 3 Hz or higher to give a real

ISSN:0895-2477    

DOI:10.1002/mop.4650061503

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

年代:1993

数据来源: WILEY

摘要:

AbstractIn this article an effective design approach which realizes high‐frequency MMIC networks in grounded coplanar waveguide (CPWG) transmission media is demonstrated. Topological features which effect electrical characteristics are highlighted and a layout topology which minimizes secondary circuit parameters is illustrated. A method is described which enables these features to be implemented while minimizing discontinuity effects, and a practical application is demonstrated with a 23‐GHz CPWG amplifier des

ISSN:0895-2477    

DOI:10.1002/mop.4650061504

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

年代:1993

数据来源: WILEY

摘要:

AbstractSubzone phase correction is a practical technique to produce high‐efficiency Fresnel zone plate antennas. In this article a strict theory underlying the technique is presented. A closed‐form expression of the focal field for the subzone phase correcting Fresnel zone plate (FZP) illuminated by a plane wave is given first. The subzone division and the corresponding phase correction are then optimized to produce the maximum focal field intensity. To overcome the difficulty of placing many subzone phase shifters in the narrow outer full‐wave zones, an aperiodic subzone phase correction technique is pro

ISSN:0895-2477    

DOI:10.1002/mop.4650061505

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

年代:1993

数据来源: WILEY

摘要:

AbstractImage reconstruction for computer tomography with missing projections using the bimodal optical computer (BOC) is studied. The computer simulation results are reported. Two real‐time processing algorithms for image enhancement are use

ISSN:0895-2477    

DOI:10.1002/mop.4650061506

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe feasibility of using a low‐gain antenna (LGA) as a mobile terminal antenna for helicopers is described in this article. The objectives are (a) to select the lowest cost antenna system which can be easily mounted on a helicopter and capable of communicating with a satellite, and (b) to determine the best antenna position on the helicopter to mitigate the signal blockage due to rotor blades and the multipath effect from the ehlicopter's body. The omnidirectional low gain antenna (LGA) is selected because it is simple, reliable, and low cost. The helix antenna is selected among the many LGAs because it is the most economical and has the widest elevation beam‐width. Both two‐ and four‐arm helices are studied experimentally to determine the antenna's performance and the scattering effects from the helicopter's body. It is found that the LGA should be located near the tail section and at least 8 in. above the hel

ISSN:0895-2477    

DOI:10.1002/mop.4650061507

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

年代:1993

数据来源: WILEY

摘要:

AbstractA simple lumped‐element equivalent circuit for a double nonsymmetrical microstrip step discontinuity has been derived using a planar approach. The model has been verified by comparison with experimental dat

ISSN:0895-2477    

DOI:10.1002/mop.4650061508

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe resonance problem of a spherical annular‐ring microstrip structure is investigated rigorously by using a Green's function formulation in the spectral domain. Numerical results of the complex resonant frequencies are obtained by using Galerkin's moment method. The convergence of the numerical calculation using different numbers of basis functions is also discussed. Typical numerical results of the resonant frequency and the quality factor, obtained from the real and imaginary parts of complex resonant frequency, for the microstrip structure used as a resonator element at TM11mode and as an efficient radiator at TM12mode are presented. Effects of the curvature on the resonant frequency and the quality factor of the structure are also analyzed and discusse

ISSN:0895-2477    

DOI:10.1002/mop.4650061509

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis article presents the design and performance of a slop dipole antenna integrated directly with an FET amplifier. The measured radiation patterns of the antenna are linear with cross‐polarization levels of 11 dB down in E plane and 17.5 dB down in H plane. The measured gain of the antenna is 10 dB at 7.1 GHz. Compared with a passive antenna, the active antenna has an extra gain of 7 d

ISSN:0895-2477    

DOI:10.1002/mop.4650061510

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

年代:1993

数据来源: WILEY

摘要:

AbstractTransversely bianisotropic uniaxial medium can be constructed by mixing metal helices into anisotropic host medium in such a way that the axes of the helices are perpendicular to a fixed direction in space but randomly oriented in the transverse plane. In general, the host medium can be either reciprocal or nonreciprocal. Eigenwaves, expressions for the plane‐wave fields, and polarization behavior are derived for the plane wave propagating perpendicular to the symmetry axis. The polarization properties of chiral and reciprocal transversely bianisotropic uniaxial medium are studied in order to find a suitable parameter combination for a polarization transformer. Several numerical examples are given to illustrate the propagation properties of the transversely bianisotropic uniaxial mediu

ISSN:0895-2477    

DOI:10.1002/mop.4650061511

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

年代:1993

数据来源: WILEY