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Title: Front and Back Matter
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Index
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Front and Back Matter
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
Download Link:Click here to download PDF     File Size: 161 KB

Title: March 2004 Special Conference Issue Full Download
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: March 2004 Regular Full Issue
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Reflection compensation scheme for the efficient and accurate computation of waveguide discontinuities in photonic crystals
Abstract: Abstract—We presented a novel method for the accurate and efficient computation of the reflection and transmission coefficients of waveguide discontinuities within planar photonic crystals (PhCs). This method proposes a novel kind of field source that optimally excites the dominant waveguide mode and mimics procedures that are typically used for the measurement of reflection coefficients. This technique may be applied to arbitrary field simulators working in the frequency domain. The presented reflection compensation scheme is elucidated along the Method of Auxiliary Sources (MAS). In order to verify the results, we compare two test cases with the rigorous connection technique provided by the Multiple Multipole Method (MMP).
Author(s): D. Karkashadze, R. Zaridze , A. Bijamov
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: GENERALIZED DESIGN OF MULTI-RESONANT DIPOLE ANTENNAS USING KOCH CURVES
Abstract: Abstract: Generalizations of fractal Koch curves and their use in designing multi-resonant antennas are presented in this paper. Both recursive and non-recursive generalizations of the curve are examined. Variation of the indentation angle is used for this approach. Although this variation has a direct bearing on the unfolded length of the curve, this should be considered as a primary variable since several geometries with the same unfolded length can be constructed with different permutations of indentation angles. Antenna input characteristics such as the primary resonant frequency, the input resistance at this resonance, and ratios of the first few resonant frequencies have been studied by numerical simulations. This study shows that it is possible to design multiresonant antennas using Koch curves with various indentation angles. Identifying similar parameters with other known fractal geometries would offer a viable route for designing multiband and multifunctional antennas for modern wireless applications using them.
Author(s): K.J. Vinoy, Jose K. Abraham, V.K. Varadan
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Iterative Solution to the Multiple Scattering by A System of Two Infinitely Long Conducting Strips
Abstract: An analytic solution to the problem of a plane electromagnetic wave scattering by two infinitely long conducting strips is presented using an iterative procedure to account for the multiple scattered field between the strips. To compute the higher order terms of the scattered fields, the translation addition theorem for Mathieu functions is implemented to express the field scattered by one strip in terms of the elliptic coordinate system of the other strip in order to impose the boundary conditions. Scattered field coefficients of high order fields are obtained and written in matrix form. Numerical results are plotted for the scattered in far zone for different strip widths, electrical separations and angles of incidence.
Author(s): A-K. Hamid, M. I. Hussein
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Numerical Analysis of Impedance of Asymmetric TEM Cell Filled With Inhomogeneous, Isotropic Dielectric
Abstract: Abstract��This paper investigates the effect of vertically offset septum on characteristic impedance (Z0) of transverse electromagnetic (TEM) cell. The Septum is considered to be of finite thickness for the analysis. Impedance analysis is done initially for symmetric TEM cell with homogenous dielectric using Finite Element Method (FEM) and the numerical results included are compared with results obtained by other authors. A good agreement is established. Numerical analysis using FEM is also done for Z0 of Asymmetric TEM cell with septum of finite thickness filled with inhomogeneous dielectric. The effect of inhomogenity and offset of septum on Z0 is discussed. Variation of Z0 with width of the septum is represented graphically
Author(s): K. Malathi, Annapurna Das
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: AUTOMATIC CALCULATION OF BAND DIAGRAMS OF PHOTONIC CRYSTALS USING THE MULTIPLE MULTIPOLE METHOD
Abstract: ABSTRACT – In the framework of photonic crystal’s band structure calculations, we present a novel way – based on several advanced techniques for searching and tracing eigenvalues with the multiple multipole program – to compute these diagrams automatically, efficiently, and with a high accuracy. Finally, we validate the results for some well known test cases.
Author(s): J. Smajic, C. Hafner, D. Erni, Jasmin Smajic, Christian Hafner, Daniel Erni
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Thin Wire Representation of the Vertical Conductor in Surge Simulation
Abstract: Abstract— Simulation of very fast surge phenomena in a three-dimensional (3-D) structure requires a method based on Maxwell’s equations, such as the FDTD (finite difference time domain) method or the MoM (method of moments), because circuit-equation-based methods cannot handle the phenomena. This paper describes a method of thin wire representation of the vertical conductor system for the FDTD method which is suitable for the 3-D surge simulation. The thin wire representation is indispensable to simulate electromagnetic surges on wires or steel frames of which the radius is smaller than a discretized space step used in the FDTD simulation. A general surge analysis program named VSTL (Virtual Surge Test Lab.) based on the Maxwell equations formulated by the FDTD method is used to simulate the surge phenomena of a vertical conductor, including the effects of ground plane and without ground plane. By use of the Maxwell equations, VSTL is inherently able to take into account the three-dimensional geometrical features of a simulated structure unlike EMTP-type circuit-based transient programs. Comparisons between calculated results by the FDTD method, theoretical results and computed results by the NEC-2 (Numerical Electromagnetic Code) based on the MoM are presented to show the accuracy of the thin wire representation.
Author(s): Md. Osman Goni, Eiji Kaneko, Hideomi Takahashi
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Use of Model-Based Parameter Estimation for Fast RCS Computation of a Conducting Body of Revolution over a Frequency Band
Abstract: Abstract—Frequency-derivative information incorporated with model-based parameter estimation (MBPE) is used to obtain scattering from a perfectly conducting body of revolution (BOR). The electric field integral equation (EFIE) is solved using the method of moments (MoM) to obtain the surface current on the perfectly conducting body. Instead of computing the MoM solution using a pointwise approach, a rational function model is used to approximate the current as a function of frequency. The model coefficients are computed using both frequency and frequency-derivative information at one frequency in the band or alternatively two or more frequencies in the band. With the rotational symmetry of BOR, the computational cost can be significantly reduced compared to that of arbitrary three-dimensional (3-D) objects and more importantly scattering from an electrically large body can be obtained. Numerical results for various perfectly conducting bodies are presented. Results show that the MBPE provides excellent agreement with the pointwise approach over a limited frequency band. In addition, the MBPE performs well for predicting sharp resonances.
Author(s): Hyunwung Son, Joseph R. Mautz, Ercument Arvas
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
Download Link:Click here to download PDF     File Size: 437 KB

Title: Triangular Grids: A Review of Resonator and Waveguide Analysis with Classical FIT and Some Reflections on Yee-like FIT- and FEM-Schemes
Abstract: Abstract—The focus of this paper is on the solution of Maxwell's equations on triangular orthogonal grids for timeharmonic elds in cylindrically symmetric resonators and general time dependant elds in length-homogeneous waveguides, respectively. The method is based on the Finite Integration Technique (FIT) [1], [2]. The 2D simulation on a structured triangular grid combines the advantages of FIT, as e.g. the consistency of the method or the numerical advantage of banded system matrices, with the geometrical exibility of noncoordinate grids. FIT on triangular grids was rst introduced in [3], [4]1. This paper presents a review describing the underlying theory in FIT operator notation rst introduced in [2] and puts this classical approach for FIT on triangular grids in relation to actual research in the eld.
Author(s): URSULA VAN RIENEN
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Envelope - Finite Element (EVFE) Technique in Electromagnetics with Perfectly Matched Layer (PML)
Abstract: Abstract — In this paper, the perfectly matched layer (PML) has been implemented into the Envelope Finite Element (EVFE) technique. The PML performance tests show that it can provide sufficient absorption of the incident waves both in 2D and 3D cases. The 3D guided wave structures are efficiently analyzed by the EVFE technique with the PML boundary condition. Furthermore, a new plane wave excitation scheme inside the PML boundary with EVFE technique is also presented here for the analysis of scattering problems, and the numerical examples validate the formulations.
Author(s): Weijun Yao, Yuanxun Wang, Tatsuo Itoh
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
Download Link:Click here to download PDF     File Size: 467 KB

Title: Applications of the Transmission Line Matrix Method to Microwave Scanning Microscopy
Abstract: Abstract - A three-dimensional transmission-line matrix (TLM) model was developed to simulate microwave-scanning microscopy. A TLM algorithm that allows the simulation of the scanning was developed. Numerical modeling was carried out for frequencies that are commonly used in microwave nondestructive testing (1GHz – 20GHz). Structures with local discontinuities in the electric permittivity are modeled numerically. The excitation parameters used in numerical modeling of scanning microwave microscopy were determined based on an initial frequency experimental response obtained from a plate with known permittivity. The numerical model developed in this paper is based on the symmetric condensed node. The description of the TLM algorithm is given in a Hilbert space using a three-index notation.
Author(s): Razvan Ciocan, Nathan Ida, Eugenia Ciocan, Huabei Jiang
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
Download Link:Click here to download PDF     File Size: 163 KB

Title: A Novel 3D Pseudo-spectral Analysis of Photonic Crystal Slabs
Abstract: Abstract—We consider a double-periodic slab which is characterized by two lattice vectors a1 and a2 on the (x;y)ˇplane, the thickness hz and a three-dimensional scalar function e(x;y; z) specifying the dielectric constitution of the slab. Above and below the slab is free space. These assumptions imply that the zˇdirection is special in this problem. Therefore, following a general scheme we diagonalize the Maxwell’s equations with respect to this direction. The periodicity in two directions suggests the use of spatially harmonic functions as a basis. We exploit this property; however, contrary to the traditional schemes, we propose an expansion of the fields in the form Y(r; z) = ĺn fn(z)exp( jkn ˘ r) allowing fn(z) to be a fairly general function of the z-coordinate, rather than an exponential function. In this expression r is the position vector in the (x;yˇ) transversal plane. To guarantee maximum flexibility we discretize f in terms of finite differences. We demonstrate the superiority of our method by discussing the following properties: i) Diagonalization only involves the transversal field components, ii) Diagonalization allows us easily to construct and implement various boundary conditions at the bounding surfaces z = 0 and z = hz, iii) The resulting discretized system is extraordinarily stable and robust, and facilitates fast computations; from the computational performance point of view it compares well with existing methods, while it by far applies to larger class of problems, iv) It allows to use both the radian frequency w and the wavevector K as input parameters. Therefore, the resulting discrete system can be solved at individual (w;K)-points of interest, v) Finally, the method is applicable to both the eigenstate end the excitation problems.
Author(s): K. Varis, A. R. Baghai-Wadji
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: A hybrid full MAS and Combined MAS/TSA Algorithm for Electromagnetic Induction Sensing
Abstract: Abstract –Electromagnetic induction (EMI) sensing, in both frequency and time domains, is emerging as one of the most promising remote sensing technologies for detection and discrimination of buried metallic objects, particularly unexploded ordinance (UXO). UXO sites are highly contaminated with metallic clutter so that the major problem is discrimination not detection. This requires high fidelity forward modeling for successful inversion and classification. Recently, the method of auxiliary sources (MAS) has been applied for solving a large range of ultra-wideband (1 Hz- 300 kHz) electromagnetic induction problems [1] - [6]. For a highly conducting and permeable metallic object, when the skin depth becomes small (at high frequency, i.e. induction number >100) the efficiency of the MAS is reduced significantly [6]. Other methods are stressed in this region as well. At the same time the Thin Skin Approximation (TSA) [7] - [9], which is based on the divergence free Maxwell's equation in a thin layer, infinitely close to the boundary interior, has shown very accurate results at high frequency/induction number. In this paper a hybrid algorithm, with standard MAS and also the MAS with TSA, is introduced and applied for solving the electromagnetic induction forward problem. Once the broadband frequency domain (FD) electromagnetic response is found it is translated into time domain (TD) using an inverse Fourier transform specialized for the characteristic TD input form. Numerical experiments are performed for highly conducting and permeable canonical objects, illuminated by a magnetic dipole or a loop antenna. These tests indicate that an algorithm using either the full MAS or MAS-TSA formulation, where appropriate, should provide a simulator that is applicable and efficient enough for fast 3-D solutions on a PC, under all conditions across the EMI band in both frequency and time domains.
Author(s): F. Shubitidze, K. O’Neill, K. Sun, I. Shamatava, K. D. Paulsen
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: A Novel Dirichlet-Neumann Random-Walk Algorithm for the Solution of Time-Harmonic Helmholtz Equation at Multiple Wavelength Length Scales: 1D and 2D Verification
Abstract: Abstract: The electrical properties of IC interconnects at multi-GHz frequencies must be described with Maxwell’s equations. We have created an entirely new floating random-walk (RW) algorithm to solve the timeharmonic Maxwell-Helmholtz equations. Traditional RW algorithms for Maxwell-Helmholtz equations are constrained to length scales that are less than a quarterwavelength. This is because of the problem of resonance in finite-domain Green’s function for Helmholtz equation at multiple quarter-wavelength length scales. In this paper, we report the major discovery of extending our floating RW algorithm beyond a quarter-wavelength. The problem of Green’s function resonance has been eliminated by the use of an infinite-domain Green’s function. In this work, we formulate this algorithm and describe its successful application to homogeneous and heterogeneous 1D problems and homogeneous 2D problems. We believe, that with additional work, this RW algorithm will prove useful in the development of CAD tools for electromagnetic analysis of IC interconnect systems. It can be noted that the algorithm exhibits full parallelism, requiring minimal interprocessor communication. Thus, significant performance enhancement can be expected in any future parallel software or hardware implementation.
Author(s): K. Chatterjee, P. Matos, Y. L Le Coz
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: A Novel Numerical Approach for the Analysis of 2D MEMS-Based Variable Capacitors Including the Effect of Arbitrary Motions
Abstract: A novel time-domain technique is proposed for the analysis of MEMS-based variable devices involving motion to arbitrary in-plane directions using the adaptive body fitted grid generation method with moving boundaries. MEMS technology is growing rapidly in the RF field and the accurate design of RF MEMS switches that can be used for phase shifting or reconfigurable tuners requires the computationally effective modeling of their transient and steady-state behavior including the accurate analysis of their time-dependent moving boundaries. Due to the limitations of the conventional time-domain numerical techniques, it is tedious to simulate these problems numerically. The new technique proposed in this paper is based on the time-difference time-domain method with an adaptive implementation of grid generation. Employing this transformation, it is possible to apply the grid generation technique to the analysis of geometries with time-changing boundary conditions. A variable capacitor that consists of two metal plates that can move to arbitrary in-plane directions is analyzed as a benchmark. The numerical results expressing the relationship between the velocity of the plates and the capacitance are shown and the transient effect is accurately modeled.
Author(s): Michiko Kuroda , Noriyuki Miura
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Coupling Between Highly Conducting and Permeable Metallic Objects in the EMI Frequency Range
Abstract:
Author(s): F. Shubitidze , K. O’Neill, I. Shamatava , K. Sun
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Numerical Study of Coupling between Coagulators and Electrodes of Cardiac Pacemakers under Consideration of the Human Body
Abstract: The paper presents a numerical, worst-case study of the coupling between coagulators and cardiac pacemakers under consideration of the human body. For this purpose two special body models have been implemented. With these models whose electrical properties correspond to a weighted average of those of different tissues of the human body the influence of the latter can be taken into account in the computations. Different parameters such as position of the pacemaker and its electrode, coagulation frequency, and coagulation point on the surface of the human body are considered. Based on results of previous investigations simplified approaches to account for the dielectric coating of the coagulator electrode and housing of the pacemaker can be used. The investigation shows, that for the scenario described above, strong peaks occur in the resulting graphs arising form resonance effects on the coagulator cable.
Author(s): Markus Schick, Friedrich M. Landstorfer
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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Title: Correlation between the geometrical characteristics and dielectric polarizability of polyhedra
Abstract: This article analyzes polarizability characteristics of the five regular polyhedra (tetrahedron, cube, octahedron, dodecahedron, and icosahedron) and sphere. In particular, the variation of the polarizabilities (polarizability is the amplitude of the static dipole moment caused by an incident electric field of unit amplitude) is correlated with various geometrical parameters of these Platonic solids: specific surface, number of edges, vertices, and faces, and the volumes of inscribed and circumscribed spheres. It is found that the polarizabilities of perfect electric conductor (PEC) and perfect electric insulator (PEI) objects are most strongly correlated with two different parameters: the radius ratio of circum- and inscribed spheres (PEC case) and the normalized radius of the inscribed sphere (PEI case).
Author(s): Ari Sihvola, Pasi Yla-Oijala, Seppo Jarvenpaa , Juha Avelin
File Type: Journal Paper
Issue:Volume: 19      Number: 1      Year: 2004
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