An innovative approach to computing the high-frequency radar cross sections (RCSs) of complex targets in real time, using a 3-D graphics workstation, is presented. The target (typically, an aircraft) modeled with I-IDEAS solid-modeling software, parametric-surface approach. RCS obtained through physical optics (PO), method equivalent currents (MEC), theory diffraction (PTD), and impedance boundary condition (IBC) techniques. CPU time for prediction spent only on electromagnetic part...

This paper presents a new and original approach for computing the high-frequency radar cross section (RCS) of complex targets in real time with 3-D graphics workstation. The aircraft is modeled I-DEAS solid modeling software using parametric surface approach. High-frequency RCS obtained through physical optics (PO), method equivalent currents (MEC), theory diffraction (PTD), impedance boundary condition (IBC). based on implementation techniques which authors have called graphical...

The multiscale compressed block decomposition algorithm (MS-CBD) is presented for highly accelerated direct (non iterative) solution of electromagnetic scattering and radiation problems with the method moments (MoM). demonstrated to exhibit <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$N^{2}$</tex> </formula> computational complexity storage requirements scaling...

The Multilevel Adaptive Cross Approximation (MLACA) is proposed as a fast method to accelerate the matrix-vector products in iterative solution of linear system that results from discretization electromagnetic Integral Equations (IE) with Method Moments (MoM). single level ACA, already described literature, extended multilevel recursive algorithm order improve asymptotical complexity both computational cost and memory requirements. main qualities ACA are maintained: it purely algebraic...

This paper presents a synthetic aperture radar (SAR) simulator that is able to generate polarimetric SAR (POLSAR) and inverse data of complex targets. It solves the electromagnetic problem via high-frequency approximations, such as physical optics theory diffraction, with notable computational efficiency. In principle, any orbital monostatic sensor working at band, resolution, operating mode can be modeled. To make simulations more realistic, target's bearing speed are considered, for...

We present a novel method of moments (MoM)-magnetic field integral equation (MFIE) discretization that performs closely to the MoM-EFIE in electromagnetic analysis moderately small objects. This new MoM-MFIE makes use set basis functions we name monopolar Rao-Wilton-Glisson (RWG) and are derived from RWG functions. show for wide variety objects -curved sharp-edged-that formulation outperforms conventional with

A prototype imaging system for active microwave tomography using cylindrical geometry has been developed, making it possible to obtain images of the dielectric properties biological targets at 2.45 GHz. This configuration allows a fast exploration body slices placed along array axis, in way similar that present X-ray scanners. The electromagnetic compatibility (EMC) this approach is critical because strongly attenuated received fields are measured on same which being used emit high-level...

The multilevel matrix decomposition algorithm (MLMDA) was originally developed by Michielsen and Boag for 2D TMz scattering problems later implemented in 3D Rius et al. MLMDA particularly efficient accurate piece-wise planar objects such as printed antennas. However, arbitrary it not the fast multipole (MLFMA) compression error too large practical applications. This paper will introduce some improvements MLMDA, like new placement of equivalent functions SVD postcompression. first is crucial...

For electromagnetic analysis using method of moments (MoM), three-dimensional (3-D) arbitrary conducting surfaces are often discretized in Rao, Wilton and Glisson basis functions. The MoM Galerkin discretization the magnetic field integral equation (MFIE) includes a factor /spl Omega//sub 0/ equal to solid angle external surface at testing points, which is 2/spl pi/ everywhere on object, except edges or tips that constitute set zero measure. However, standard formulation MFIE with 0/=2/spl...

We present a novel technique to integrate analytically the highest-order terms of Kernel low-order curl-conforming magnetic-field integral equation (MFIE) operator. In computation bistatic RCS moderately small perfectly conducting sharp-edged examples, we show that this choice yields very similar performance MoM-EFIE formulation and outperforms MoM-MFIE based on RWG basis functions, both with accurate integration. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 354–358, 2005;...

A novel algorithm, the compressed block decomposition (CBD), is presented for highly accelerated direct (noniterative) method of moments (MoM) solution electromagnetic scattering and radiation problems. The algorithm based on a block-wise subdivision MoM impedance matrix. Impedance matrix subblocks corresponding to distant subregions problem geometry are not calculated directly, but approximated in form. Subsequently, decomposed preserving compression. Examples typical problems range 5000...

Hypersingular 4-D integrals, arising in the Galerkin discretization of surface integral equation formulations, are computed by means direct evaluation method. The proposed scheme extends basic idea singularity cancellation methods, usually employed for regularization singular kernel, utilizing a series coordinate transformations combined with reordering integrations. overall algebraic manipulation results smooth 2-D integrals that can be easily evaluated via standard quadrature rules....

A comparative study at 2.45 GHz concerning both measurement and reconstruction parameters for planar cylindrical configurations is presented. For the sake of comparison, a numerical model consisting two nonconcentric cylinders considered reconstructed using geometries from simulated experimental data. The scattered fields images permit extraction very useful information about dynamic range, sensitivity, resolution, quantitative image accuracy choice configuration in particular application....

Galerkin implementations of the method moments (MoM) electric-field integral equation (EFIE) have been traditionally carried out with divergence-conforming sets. The normal-continuity constraint across edges gives rise to cumbersome around junctions for composite objects and less accurate combined field (CFIE) closed sharp-edged conductors. We present a new MoM-discretization EFIE conductors based on nonconforming monopolar-RWG set, no continuity edges. This approach, which we call...

The multilevel matrix decomposition algorithm (MLMDA) has been implemented in 3-D for the solution of large electromagnetic problems. electric field integral equation is solved arbitrary surfaces discretized using N Rao, Wilton, and Glisson basis functions. MLMDA accelerates matrix–vector products a conjugate gradient or biconjugate iterative resulting system equations. computational cost each iteration proportional to log2 very problems, particularly small planar piecewise objects. ©1999...

This paper presents a modification of the adaptive cross approximation (ACA) algorithm for accelerated solution Method Moments linear system electrically large radiation and scattering problems. As with ACA, subblocks impedance matrix that represent interaction between well separated subdomains are substituted by "compressed" approximations allowing reduced storage iterative solution. The modified approximates original products sparse matrices, constructed aid ACA sub-sampling basis...

A novel integral formulation of the measured equation invariance method is derived from reciprocity theorem and implemented for perfectly conducting (PEC) 2-D scattering problems. This uses electric magnetic Green's functions environment to obtain a matrix induced surface current with same number unknowns as conventional boundary element-method moments (BE-MoM) approach. However, that must be inverted in new sparse circulant, only three non-zero elements per row. Sample results...

The application of integral equation methods based on the method moments discretization to solve large antenna arrays is difficult due fact that computational requirements increase rapidly with number unknowns. This critical when a frequency analysis required. We propose multilevel matrix decomposition algorithm (MLMDA) carry out this purpose efficiently. As MLMDA particularly well-suited for planar structures any Green's function, it very efficient approach microstrip arrays.

We present new implementations in Method of Moments two types second kind integral equations: (i) the recently proposed Electric-Magnetic Field Integral Equation (EMFIE), for perfectly conducting objects, and (ii) Müller formulation, homogeneous or piecewise dielectric objects.We adopt Taylororthogonal basis functions, a presented set facet-oriented which, as we show this paper, arise from Taylor's expansion current at centroid discretization triangles.We that Taylor-orthogonal EMFIE...

This paper addresses the direct (noniterative) solution of method-of-moments (MoM) linear system, accelerated through block-wise compression MoM impedance matrix. Efficient matrix block is achieved using adaptive cross-approximation (ACA) algorithm and truncated singular value decomposition (SVD) postcompression. Subsequently, a applied that preserves allows for fast by backsubstitution. Although not as some iterative methods very large problems, has several desirable features, including:...

The adaptive cross approximation (ACA) algorithm, when used to accelerate the numerical solution of integral equations for radiation and scattering problems, sometimes suffers from inaccuracies. These inaccuracies occur ACA convergence criterion, which is based on an residual relative error, prematurely satisfied. This paper identifies two sources this problem proposes adaptations algorithm that remedy them.

The multilevel matrix decomposition algorithm (MLMDA) has been implemented in 3-D for the solution of large electromagnetic problems. electric field integral equation is solved arbitrary surfaces discretized using N Rao, Wilton, and Glisson basis functions. MLMDA accelerates matrix–vector products a conjugate gradient or biconjugate iterative resulting system equations. computational cost each iteration proportional to log2 very problems, particularly small planar piecewise objects. ©1999...

Terahertz spectroscopy is a promising method to diagnose ocular diseases, where the cornea typically imaged by Gaussian beams. However, beam’s mismatch with cornea’s spherical surface produces 5-10 % error in analysis. We investigate wavefront-modified vector beams, reducing original analysis less than 0.5 %. Vector beams are synthesized our developed 3D Angular Spectrum Method expanded harmonic presentation, allowing wavefront modification and scattering from 100-layer models. show that...

The volumetric monopolar-RWG discretization of the electric-field integral equation (EFIE) imposes no continuity constraint across edges in surface around a closed conductor. current is expanded with set and electric field tested over tetrahedral elements attached to boundary surface. This scheme facet-oriented therefore, well suited for scattering analysis nonconformal meshes or composite objects. observed accuracy, though, only competitive respect RWG-discretization restricted range...