Wei-Bin Ewe

Fast solution of mixed dielectric/conducting scattering problem using volume-surface adaptive Integral method

This paper presents the adaptive integral method utilized to solve scattering problems of mixed dielectric and conducting objects using volume-surface integral equation. The scattering problem is formulated using volume integral equation and surface integral equation for dielectric material object and conducting object, respectively. The combined field integral equation is formulated to treat closed conducting surfaces. The method of moments is applied to discretize the integral equations. The resultant matrix system is solved by an iterative solver where the adaptive integral method is employed to accelerate the matrix-vector multiplication. The block diagonal preconditioner is implemented to further accelerate the convergence of the present solution. Numerical results are presented to demonstrate the accuracy and efficiency of the technique.

Analysis of Reflector and Horn Antennas Using Adaptive Integral Method

This paper presents an analysis of electrically large antennas using the adaptive integral method (AIM). The arbitrarily shaped perfectly conducting surfaces are modeled using triangular patches and the associated electric field integral equation (EFIE) is solved for computing the radiation patterns of these antennas. The method of moments (MoM) is used to discretize the integral equations and the resultant matrix system will be solved by an iterative solver. The AIM is employed in the iterative solver to speed up the matrix-vector multiplication and to reduce the memory requirement. As specific applications, radiation patterns of parabolic reflectors and X-band horns are computed using the proposed method.

AIM Analysis of Scattering and Radiation by Arbitrary Surface-Wire Configurations

The adaptive integral method is utilized to solve electromagnetic scattering and radiation problems of conducting surface-wire configurations. The method of moments (MoM) is applied to establish the integral equations where triangular type basis functions are used to represent the currents on surfaces and wires. Attachment mode has been used to model the surface-wire junction to ensure the current continuity. The resultant matrix system is then solved by an iterative solver where the adaptive integral method (AIM) is employed to reduce memory requirements and to accelerate the matrix-vector multiplications. Numerical results are presented to demonstrate the accuracy and efficiency of the present technique for the arbitrary surface-wire configurations

Solving Mixed Dielectric/Conducting Scattering Problem Using Adaptive Integral Method

This paper presents the adaptive integral method (AIM) utilized to solve scattering problem of mixed dielectric/conducting objects. The scattering problem is formulated using the Poggio-Miller- Chang-Harrington-Wu-Tsai (PMCHWT) formulation and the electric field integral equation approach for the dielectric and conducting bodies, respectively. The integral equations solved using these approaches can eliminate the interior resonance of dielectric bodies and produce accurate results. The method of moments (MoM) is applied to discretize the integral equations and the resultant matrix system is solved by an iterative solver. The AIM is used then to reduce the memory requirement for storage and to speed up the matrix-vector multiplication in the iterative solver. Numerical results are finally presented to demonstrate the accuracy and efficiency of the technique.

AIM Analysis of Electromagnetic Scattering by Arbitrarily Shaped Magnetodielectric Object

A fast solution to the electromagnetic scattering by large-scale three-dimensional magnetodielectric objects with arbitrary permittivity and permeability is presented. The scattering problem is characterized by using coupled field volume integral equation (CF-VIE). By considering the total electric and magnetic fields, i.e., the sum of incident fields and the radiated fields by equivalent electric and magnetic volume currents, the CF-VIE can be established in the volume of the scatterers. The resultant CF-VIE is discretized and solved by using the method of moments (MoM). For large-scale scattering problems, the adaptive integral method (AIM) is then applied in the MoM in order to reduce the memory requirement and accelerate the matrix-vector multiplication in the iterative solver. The conventional AIM has been modified to cope with the two sets of equivalent volume currents.

Preconditioners for adaptive integral method implementation

The performance of three preconditioners, namely, diagonal, block-diagonal, and incomplete lower-upper preconditioners, are investigated in this communication for increasing the efficiency of iterative solvers in adaptive integral method implementation. These preconditioners are implemented to accelerate the solution of electromagnetic scattering problems in a comparative study. Numerical results have shown some improvements in convergence rate, when these preconditioners are employed.

AIM solution to electromagnetic scattering using parametric geometry

This paper presents the adaptive integral method (AIM) utilized to solve electromagnetic scattering problems of an arbitrarily shaped conducting body with parametric geometry. The combined field integral equation is used to characterize the scattering problems of a closed conducting body whose surfaces are modeled using curvilinear patches. The formulated integral equations are then discretized and converted to a matrix equation using the method of moments. The resultant matrix equation is then solved by an iterative solver and the AIM is employed to accelerate the matrix-vector multiplication. Numerical results are presented to demonstrate the efficiency of the technique.

Optical properties of a single-chain of elliptical silver nanowires

The optical response in visible wavelengths of a single-chain of elliptical silver nanowires is investigated for different separation distances and illumination directions. The efficient and simple method, surface integral equation, is used to characterize the above arrays. The results show that the occurrence and magnitude of plasmon resonances as well as the field intensity are depended on these parameters. Strong field enhancement can be observed in the gap between nanowires of the single chain.

Investigation of Surface Plasmon Resonance of Nanoparticles using Volume Integral Equation

This paper investigates the interactions between incident electromagnetic wave and nanoparticles, especially metallic nanoparticles. The scattering of nanoparticles is characterized by using volume integral equation. By considering the total electric field, i.e. the sum of incident fields and the radiated fields by equivalent electric volume currents, the volume integral equation can be established within the scatterers. The resultant volume integral equation is discretized using appropriate basis functions and is solved numerically using a matrix solver. Numerical results are presented to demonstrate the application of volume integral equation to analyze the plasmon resonance.

Adaptive Integral Method for Electromagnetic Scattering and Antenna Radiation

This paper presents an efficient and fast solver developed based on the adaptive integral method and its application for characterizing electromagnetic scattering by arbitrarily shaped objects, and designing antennas for large scaled radio radiation problems. Although a brief summary of the historical development will be given, the emphasis of the paper will be given to the recent advances and new developments made quite recently. During the development procedure, the method of moments (MoM) has been considered and applied as a foundation to start with for discretizing the integral equations. The resultant matrix system of a large dimension is then solved by an iterative solver where the adaptive integral method (AIM) is employed on the top of them to accelerate the matrix-vector multiplications and to reduce matrix storage. Various numerical results are presented to demonstrate the accuracy, efficiency, and applicability of the technique.