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The well-known Method of Moments (MoM) formulation is used for the analysis of several three-dimensional problems comprising left-handed materials, plasmonic nanoparticles, and dielectric objects. The problems are formulated in terms of surface integral equations (SIEs), requiring only the discretization of the material boundary surfaces and interfaces to expand the unknown electric and magnetic equivalent currents. The numerical examples presented demonstrate the versatility and capabilities of the SIE-MoM approach to deal with complex composite bodies involving different kinds of media in the context of nanoscience and nanotechnology. [ABSTRACT FROM AUTHOR]

A wide analysis of left-handed material (LHM) spheres with different constitutive parameters has been carried out employing different integral-equation formulations based on the Method of Moments. The study is focused on the accuracy assessment of formulations combining normal equations (combined normal formulation, CNF), tangential equations (combined tangential formulation, CTF, and Poggio-Miller-Chang-Harrington-Wu-Tsai formulation, PM-CHWT) and both of them (electric and magnetic current combined field integral equation, JMCFIE) when dealing with LHM's. Relevant and informative features as the condition number, the eigenvalues distribution and the iterative response are analyzed. The obtained results show up the suitability of the JMCFIE for this kind of analysis in contrast with the unreliable behavior of the other approaches. [ABSTRACT FROM AUTHOR]

The Khayat-Wilton singularity cancellation technique has been adapted for computing the potential integrals involving the 3D Green's function and the linearly-phased Rao-Wilton-Glisson (LP-RWG) basis functions. The LP-RWG basis functions are used to expand the induced currents in terms of current-modes, which allows an efficient representation of the currents in large scatters using a fewer number of unknowns. The proposed procedure overcomes some drawbacks of other singularity schemes, such as the dependence of the triangular-patch shape and the location of the observation points. In this sense, the proposed procedure is valid for singularities and “near” singularities on arbitrarily-shaped triangular meshes. This significantly improves the reliability of the method of moments and related approaches in combination with the asymptotic phase formulation when dealing with arbitrary and automatically generated surface meshes. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2189–2197, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22680 [ABSTRACT FROM AUTHOR]

This paper presents a method of moments (MoM) formulation for large thin-wire structures. In our approach, a modified version of the well-known Rao–Wilton–Glisson (RWG) basis functions for wires including a linear phase term is considered. This additional term allows an efficient representation of the travelling-wave modes on each wire, while it preserves the main advantages of RWG bases for arbitrarily complex wire topologies. The paper contains a detailed description of the algorithm used for the computation of the impedance matrix integrals. Finally, some results for scattering problems are presented to show the agreement with the conventional RWG-MoM solution. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 960–966, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21533 [ABSTRACT FROM AUTHOR]

A linear-phase term is incorporated into the triangular-type Rao–Wilton–Glisson (RWG) vector basis functions in the method of moments (MoM) formulation. The objective consists of including the dominant phase variation of the current density within the basis-functions formulation, thus allowing an efficient representation of the induced current on large bodies using fewer unknowns. Assuming a good estimation of the phase variation, the new MoM formulation with linearly-phased RWG basis functions is shown to greatly relieve the storage and solution time of the conventional MoM with RWG basis functions, while accurately reproducing the scattered fields of some chosen problems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 106–112, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20560 [ABSTRACT FROM AUTHOR]

This article presents a new procedure for the synthesis of array antennas mounted over complex vehicular platforms, where an accurate control of the electromagnetic interference and disturbances (EMI) between systems is required. This is done by including into the overall optimization procedure near-field restrictions over those regions of the platform where sensitive devices are installed. The electromagnetic coupling between the radiating systems and with the platform is modeled by an accurate three-dimensional method-of-moments formulation. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 188–191, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10413 [ABSTRACT FROM AUTHOR]

Array antennas mounted on aircraft, ships, or any other complex platform suffer from mutual coupling and coupling with the platform in the transmission or reception of electromagnetic waves. These coupling effects affect the estimation of the direction of arrival (DOA) of plane waves performed with on-board antennas. With the use of the method of moments (MoM) to model these electromagnetic (EM) coupling terms, closed-matrix expressions for the Cramer–Rao bound (CRB) are obtained for on-board array antennas considering both mutual coupling and platform coupling effects. Some significant differences in the CRB have been found when this bound is compared with the same bound calculated in an ideal free coupling environment. Numerical results are shown to illustrate these effects. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 119–123, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10249 [ABSTRACT FROM AUTHOR]

This article presents a general-purpose educational software applied to electromagnetics engineering education. The program presented allows the students to obtain the RCS, current density, and near field distributions of perfectly electric conducting (PEC) canonical geometries being illuminated by arbitrary incident plane waves. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 33–44, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10015 [ABSTRACT FROM AUTHOR]

This paper presents an alternative procedure for the evaluation of the physical optics (PO) contribution into a hybrid moment method–physical optics (MM–PO) code. The proposed formulation includes a linear interpolation of the phase over large triangular subdomains for the PO regions, where the radiated field can be analytically determined. This allows a drastic reduction of the computational cost, while maintaining or even improving the degree of accuracy. In this way, the scope of application of the MM–PO hybrid code is enhanced to larger problems in terms of wavelength. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 357–363, 2001. [ABSTRACT FROM AUTHOR]

A floating attachment mode is presented here in order to improve the electromagnetic analysis of wire antennas attached to arbitrary surfaces when using the method of moments (MoM). This attachment mode overlaps the surface modes, allowing us to place the wire-to-surface connection at any point, independently of the surface mesh, even near or at geometrical discontinuities. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 102–105, 2001. [ABSTRACT FROM AUTHOR]

On-board antenna design involves aspects such as optimization of radiation patterns, control of electromagnetic interference and disturbance (EMC/EMI), the assessment of radiation hazards, etc. This paper describes a hybrid moment-method physical-optics (MM–PO) approach that has been shown to be an efficient and accurate tool to predict the above-mentioned electromagnetic aspects concerning antennas installed on board. Some numerical results are presented and compared with a reference MM solution in order to illustrate the accuracy and efficiency of the proposed approach. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 88–93, 2000. [ABSTRACT FROM AUTHOR]

A comparison of different testing procedures for subdomain moment-method formulations for arbitrarily shaped bodies, including attached wires, is presented here. It is shown that an accurate evaluation of the impedance matrix elements leads to important benefits over the conventional procedures. Otherwise, the use of an adaptively generated mesh—more refined nearby the sources—is shown to reduce the total number of unknowns, and therefore, the computational cost for a fixed problem. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 413–419, 2000. [ABSTRACT FROM AUTHOR]

We present a massively parallel version of the single-level fast multipole method, which allows the efficient use of hundreds of processors. A very large problem with more than 32 millions of unknowns is solved in 512 processors, which becomes a new record in scalability for this kind of problems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2451–2453, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24651 [ABSTRACT FROM AUTHOR]