摘要:

AbstractThe far field of an active antenna module comprising a MESFET device with microstrip element terminations is modeled using a large‐signal harmonic balance technique and discrete two‐dimensional equivalents of the planar circuit elements. Simulated results are presented for comparison with the measured performance of the real antenna. © 1993 John Wiley&sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060502

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe capacitances appearing in the equivalent circuit of the offset asymmetric microstrip gap discontinuity are determined in the case in which the metallizations of the discontinuity are embedded in a multilayered anisotropic substrate. The excess charge densities on the conducting strips of the discontinuity are obtained by using the Galerkin method in the spectral domain. A wide variety of results is provided to demonstrate the generality of the study carried out. © 1993 John Wiley&sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650060503

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

年代:1993

数据来源: WILEY

摘要:

AbstractAn accurate measurement of the surface resistanceRsbased on a reduced dielectric loss factor inverted microstrip configuration is reported. The inverted microstrip resonator, with a resonant frequency of 2.5 GHz in S‐band, yields a quality factor of 10,000 at 15 K and 5000 at 77 K. This corresponds toRsvalues of 1 and 26 μΩ at 15 and 77 K, respectively. © 1993 John Wiley&sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060504

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

年代:1993

数据来源: WILEY

摘要:

AbstractBy means of a small square loop antenna and an electric probe it was possible to detect significant longitudinal components of magnetic and electric fields, respectively, in the far zone in the air. Unique features of this observation are the abundance and the slow variation with radial distance of the detected longitudinal electromagnetic field components which seem to decay at a rate much slower than 1/r2. © 1993 John Wiley&sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650060505

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

年代:1993

数据来源: WILEY

摘要:

AbstractAn inexpensive system that accurately measures ranges of the order of meters, with the resolution of centimeters, is described. The synthesized pulse and phase counting methods, based on coherent transmission and quadrature detection, are discussed. Suitable calibration schemes to obtain distance measurement accuracies better than 99% are described. © 1993 John Wiley&sons, Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650060506

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

年代:1993

数据来源: WILEY

摘要:

AbstractA compact slot loop antenna is proposed and investigated experimentally. The antenna consists of a slot loop printed on a substrate, and is fed by a coaxial cable. The loop perimeter is about λ/2 and the area of the antenna is about 1/8 of that of a microstrip antenna with the same operating frequency. The operating bandwidth (defined by return loss less than or equal to ‐10 dB) of the antenna is quite large (22%). The gain is comparable with that of a λ/2 dipole. The antenna should find wide applications in TV reception, mobile communications, and satellite communications. © 1993 John Wiley&sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060507

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe choice of basis functions in the expansion of charge density using spectral‐domain methods is discussed. It is shown that the simple inclusion of the correct singular behavior of charge density close to the edges of the strip is not sufficient to get accurate results with very few basis functions. For best performance, one should be able to model correctly the first terms of the charge density expansion close to the edge. © 1993 John Wiley&sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650060508

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

年代:1993

数据来源: WILEY

摘要:

AbstractA theoretical study of bistability caused by the Kerr effect in two types of optical fiber loop resonators connected to a 3 × 3 coupler is carried out. The dependence of the bistability on various parameters of the fiber and the coupler is investigated and presented as graphs. The bistability offers the possibility of using these fiber loop resonators as optical logic gates, memories, switches, and differential amplifiers. © 1993 John Wiley&sons, In

ISSN:0895-2477    

DOI:10.1002/mop.4650060509

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

年代:1993

数据来源: WILEY

摘要:

AbstractFor scale‐model measurement of the RCS of a lossy target, it is difficult to meet all the requirements of physical similarity [1], especially in the constitutive parameters of the absorbent materials because of their frequency dependence. One often avoids this problem by keeping the wavelength of incident radiation fixed with the sizes of the target scaled down. In this case, the scale factor to evaluate the RCS of prototype from that of a scale model must be found. This article gives brief expressions of the RCS and the scale factors for simply shaped scatterers by means of a PO approximation and the method of stationary phase. It is found that the physical scale factor q2is not always proportional to the geometrical scale factor p2, but to p to the powers of 2‐4 for a variety of shaped scatterers, respectively, provided their characteristic dimensions are much greater than the working wavelength. © 1993 John Wiley&sons,

ISSN:0895-2477    

DOI:10.1002/mop.4650060510

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

年代:1993

数据来源: WILEY

摘要:

AbstractAn approach to the analysis of a spherical circular microstrip antenna which is applicable to a relatively thick substrate is presented. Based on the spectral‐domain Green's function formulation, the effect of the dielectric substrate as well as the spherical ground are incorporated. Numerical results for the radiation resistance agree well with the results using the generalized transmission line model (GTLM), which is accurate for a thin dielectric substrate only. © 1993 John Wiley&sons, I

ISSN:0895-2477    

DOI:10.1002/mop.4650060511

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

年代:1993

数据来源: WILEY