Search

In this paper, the multipole theory (MT) method is presented as a new approach for determining the cutoff frequency and analyzing the propagation characteristics of finlines. The inhomogeneous field domain of finline is treated as a combination of several simple homogeneous regions, and the solution of the governing partial differential equation is represented by a generalized MT formula. An extensive comparison with the exact data of the literature and various configurations of the finlines show the accuracy and flexibility of the MT method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 100–102, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10528 [ABSTRACT FROM AUTHOR]

For microcellular system design, we have enhanced a well-known waveguide model for propagation-loss prediction along an LOS propagation path in a tunnel. It is reported in this letter. The enhancement involves a more accurate calculation of the tilt loss, the distinction of the two propagation regions, and the suggestion of using the free-space model for one region and the waveguide model for the other. The enhancement is demonstrated with examples. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 10–12, 2001. [ABSTRACT FROM AUTHOR]

The ray-tracing technique does not take into account the effects of the inner structure of walls for indoor propagation prediction. A numerical approach to consider this problem using the FDTD method is presented. Numerical results of the path loss calculated by the FDTD method are compared to those obtained by the ray-tracing technique. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 19–21, 2001. [ABSTRACT FROM AUTHOR]

This paper describes the mathematical modeling and analysis of an indoor radio propagation system design problem that looks for an optimal location of a single transmitter. The authors present here a combination between a simple indoor propagation model and a Nelder–Mead simplex method. A comparison between this and other optimization methods shows that the Nelder–Mead method has better performance. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 146–148, 2000. [ABSTRACT FROM AUTHOR]

This letter presents a characterization of the vertical plane propagation in terms of the satellite elevation angle for different mechanisms of propagation. The effect of blockage by buildings on the received signal level versus the satellite elevation angle at L-band for urban environments is performed using the uniform theory of diffraction (UTD). © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 336–338, 2000. [ABSTRACT FROM AUTHOR]

The propagation of very short electrical pulses on tapered nonuniform planar transmission lines is rigorously investigated. The application field concerns the circuitry for impedance matching of semiconductor lasers and photodiodes in high-speed optoelectronics. For this purpose, frequency- and time-domain analysis are carried out by means of the spectral-domain approach and fast Fourier transform, respectively. Simulations using a software which includes this combined analysis are used to study pulse distortions when the terminations are reactively constrained by several types of complex load. Finally, measured results verify the adequacy of the analysis. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 22: 85–87, 1999. [ABSTRACT FROM AUTHOR]

An improved ray-tracing propagation prediction model for predicting path loss on single floors in indoor environments is developed. It utilizes the results of a two-dimensional (2-D) ray-tracing technique to deal with a three-dimensional (3-D) problem. This approach is more efficient than the usual 3-D ray-tracing model and more accurate than the usual 2-D ray-tracing model. Simulation results agree well with measurement. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 22: 39–41, 1999. [ABSTRACT FROM AUTHOR]

In this letter, pulse propagation on a high-temperature superconducting coplanar strip line is investigated theoretically using a quasi-TEM approximation with a phenomenological model proposed by the author. The results show good agreement with published experimental data. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 88–90, 1999. [ABSTRACT FROM AUTHOR]

Constitutive tensors of bianisotropic media described by continuous magnetic groups of symmetry have been recently determined. One of these groups is D∞h(C∞v). A medium with this symmetry may theoretically be synthesized using Kamenetskii's magnetostatic wave resonators with metallization. The moving isotropic medium is a special case of media described by the group D∞h(C∞v). In this paper, we investigate plane-wave propagation in such media. The dispersion equation for the media is obtained, and solutions of this equation are found and discussed. The results are verified by some known special cases. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 42–44, 1999. [ABSTRACT FROM AUTHOR]

An accurate numerical approach to study the wave guidance in multilayered dielectric waveguides having a periodic surface is presented. The complex propagation constants of a four-layered dielectric waveguide with a sinusoidal surface are calculated and compared with those obtained by other numerical methods. [ABSTRACT FROM AUTHOR]

A new rigorous diffraction coefficient formula for a two-impedance wall right-angled wedge is presented. A comparison of the total rigorous and heuristic field patterns is made for the same two impedance wall right-angled wedge. The validity and applicability of this new rigorous diffraction coefficient formula are demonstrated through propagation path loss prediction around typical right-angled scenarios. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 193–195, 1998. [ABSTRACT FROM AUTHOR]

This paper presents an application of the numerical algorithms, based on Davidenko's method. The method has been found to be an efficient technique used to model the properties of hybird surface plasmon polaritons guided by an ultra-thin metal film. A general computer program capable of providing the modeling of the mode effective index and the propagation loss (normalized attenuation constant) is written and implemented. Davidenko's algorithms allows us to obtain accurate numerical results in a very reasonable CPU time. The presented results could be useful in designing guided-wave photonic devices based on materials with relatively large absorptive losses. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 16: 122–124, 1997. [ABSTRACT FROM AUTHOR]

A simple wide-angle beam-propagation method for integrated optics is shown in this article. It is an efficient method, because it needs the same memory as BPM and requires very little increase in the computation time, whereas it improves the accuracy of BPM. This method is compared with BPM in this article and is illustrated by examples. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 14: 345–347, 1997. [ABSTRACT FROM AUTHOR]

Using the weak guidance approximation and Goell's point-matching method, a numerical analysis has been made of a guide with a pentagonal cross section, which may find wide applications in integrated optic technology. Two cases have been dealt with, namely, (i) a pentagonal guide cladded with a conducting substance, and (ii) a pentagonal guide loaded with conducting substance on alternate surfaces, the remaining surfaces being made of a dielectric substance. [ABSTRACT FROM AUTHOR]

This article discusses the method for analyzing the reflection characteristics of a metallic cylinder coated with a two-layer wave absorber. Various design curve and numerical results of the reflection characteristics are shown for wave absorbers that are optimum for masts with elliptical cross sections. [ABSTRACT FROM AUTHOR]

The phase velocity of plane waves propagating in an isotropic chiral medium can be simultaneously positive for left-circularly polarized light and negative for right-circularly polarized light (or vice versa). The constitutive parameter regimes supporting this phenomenon are established for nondissipative and dissipative mediums. The boundary between positive- and negative-phase velocity is characterized by infinite phase velocity. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1245–1246, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22434 [ABSTRACT FROM AUTHOR]

The exponential time differencing (ETD) schemes are proposed for transient propagation in dynamic collision plasmas using finite-difference time-domain method. The formulation of ETD algorithms with the first order and second accuracy is presented. The ETD algorithms are validated by comparing the simulation results with analytical values. The numerical results indicate that the ETD schemes are accurate and efficient. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1363–1364, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22424 [ABSTRACT FROM AUTHOR]

Cabeceira et al. recently presented a time-domain analysis of wave propagation in a Tellegen medium [1]. Their analysis is ill-founded because (i) the existence of any Tellegen medium is not tenable within modern electromagnetic theory; and (ii) the constitutive relations employed are not consistent with the principle of causality.© 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 345–346, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20298 [ABSTRACT FROM AUTHOR]

© 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 345–346, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20299 [ABSTRACT FROM AUTHOR]

The work of Barba et al.1 is fatally flawed on two counts: (i) the existence of Tellegen mediums is unrecognizable in modern electromagnetic theory, and (ii) the time-domain constitutive relations used in the commented upon work are noncausal. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 92–93, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11294 [ABSTRACT FROM AUTHOR]

A new application for the high-resolution processing algorithm MUSIC, applied to a rotating antenna, is presented. Experimental results show that significant improvement can be achieved using the proposed method, compared to a low-directivity rotating antenna. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 329–330, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10909 [ABSTRACT FROM AUTHOR]

Presents a correction to the article "Modal Propagation Analysis of a Waveguide With a Regular Pentagonal Cross Section With Conducting and Nonconducting Boundaries," by Vandana Misra, P. K. Choudhury, P. Khastgir and S. P. Ojha.