摘要:

AbstractPlane‐wave propagation is considered in a medium which is a generalization of the uniaxial chiral and the uniaxial omega medium, both of which have shown properties useful for the design of electromagnetic devices. The medium is reciprocal and it can be easily realized by mixing certain metal wire elements in a host material. The resulting bianisotropic medium is isotropic in directions perpendicular to an axis in space. Wave‐number expressions are derived and numerical examples considered. © 1993 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060902

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

年代:1993

数据来源: WILEY

摘要:

AbstractWe have measured the cryogenic performance of off‐the‐shelf GaAs MMIC amplifier and mixer‐converter modules from different foundries, with room‐temperature designs, without finding significant degradation in performance to 77 K. Therefore, existing MMIC modules would be suitable for hybrid microwave systems with high‐Tcsuperconducting transmission line filters, representing a cost savings. © 1993 John Wiley

ISSN:0895-2477    

DOI:10.1002/mop.4650060903

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

年代:1993

数据来源: WILEY

摘要:

AbstractA BER measurement has been performed relative to each Stokes parameter in an ASPSK system using laser sources such that the beating signal linewidth exceeds the bit rate (about 200%). Under such severe conditions a sensitivity of about 155 photons/bit has been achieved at a BER of 10−9, with a penalty of about 6 dB with respect to the quantum limit of an ASPSK system. © 1993 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650060904

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe problems of achieving slot synchronization and the proper frame frequency in optical fiber digital PPM were previously studied. Self‐synchronization of the PPM format is completed here by considering the extraction of the frame phase directly from the incoming data. An original novel technique that utilizes naturally occurring sequences has been devised and used to extract the frame phase in optical‐fiber digital PPM. Original results are reported that identify two classes of naturally occurring PPM sequences. An original mathematical model is developed and used to predict the spectral properties of these sequences. A generalization of the analysis and implementation techniques is carried out that results in synchronizers that can cope with large PPM word sizes. The improvement in the spectral discrete components per extra tracked sequence is shown to be 6 dB. Original practical results are given and shown to be in agreement with the theoretical results. © 1993 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060905

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis Letter presents a simple repeatable technique for fabricating a Fabry‐Perot interferometer in a LiNbO3waveguide. The main contribution to the optical losses of the waveguide resonator due to the wedge angles is theoretically analyzed for the first time. A waveguide Fabry‐Perot interferometer was fabricated in the waveguide with wedge angles of less than 0.01° achieved. © 1993 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650060906

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

年代:1993

数据来源: WILEY

摘要:

AbstractIt has recently been observed that the symmetric case of the biconjugate gradient method renders a variational formula for the monostatic scattering amplitude stationary in the available Krylov subspace at each iteration. In this Letter I point out that the general biconjugate gradient method makes stationary the analogous variational formula for a bistatic scattering amplitude and suggest likely practical benefits accruing from this property. © 1993 John Wiley&Sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650060907

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

年代:1993

数据来源: WILEY

摘要:

AbstractMode energy transfer along a circular open chirowaveguide is analyzed. It is shown that the TE0and the TM0are the only unperturbed modes that undergo coupling processes and that if the guide is exclusively excited with the TE01mode, or the TM01, or both, only these modes are dominant. The energy variation along the guide is then almost periodic and the distance at which the energy transfer is largest is of the order of the radius, making this device attractive as a TE → TM mode converter, especially when a cylindrical geometry is required in a specific circuit design. © 1993 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650060908

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

年代:1993

数据来源: WILEY

摘要:

AbstractTheoretical formulation using the Green's function in conjunction with the reflection coefficient matrix approach (instead of potentials) is used for calculations of fields of microstrip ring antennas. Different TM modes are studied using the magnetic cavity wall model for obtaining ring sheet currents. The results show that the ring antenna is superior to disk and rectangular patch antennas and has optimized performance for the TM12mode, with a substrate dielectric constant of 6 with high gain, broad lobe width and no side lobes. The better performance at higherrmay be of importance for array synthesis in MMIC. The theoretical approach used is simpler for calculation and is easily extendable to other situations and higher substrate thicknesses. © 1993 John Wiley&Sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650060909

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

年代:1993

数据来源: WILEY

摘要:

AbstractA new interpretation based on matrix condition number is introduced for the accurate determination of the desired break‐knee points in Mastermann's break‐point analysis of waveguide discontinuity junctions. The modified technique is favorably tested on multiple and asymmetrical iris problems. © 1993 John Wiley&Sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060910

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

年代:1993

数据来源: WILEY

摘要:

AbstractA copolarized electric field diffracted by a spherical cavity in a denser dielectric medium is analyzed in the forward near‐field region when the wavelength is comparable to one half the cavity radius. It is shown that double nulls and dips exist in the measurement plane transverse to the propagating direction of the incident field, and their dependences on the frequency, the distance of the measurement plane, and the measurement angles are analyzed. © 1993 John Wiley&Sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650060911

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

年代:1993

数据来源: WILEY