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This paper shows applied sensitivity analysis for easier design and practical application of a planar half-wavelength low-pass filter (LPF) using defected ground structure (DGS). Typically, it is difficult to deploy planar half-wavelength low-pass filters when high power durability is required because of the very narrow line-widths of high impedance transmission line. Here, we propose a new configuration for the high impedance microstrip line using DGS structure to allow broader line width and high power handling capability. The sensitivity of the scattering parameters was calculated using the self-adjoint sensitivity formula in order to determine the proposed filter's dimension. The paper also highlights the validity of the proposed LPF optimization with its measured performance. Index Terms--Defected ground structure (DGS), low-pass filter (LPF), self-adjoint method, sensitivity analysis.

This paper deals with optimum design criteria for maximum torque density and minimum torque ripple of Synchronous Reluctance Motor (SynRM) according to the rated wattage using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with the finite element method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. The proposed procedure allows to define the rotor optimum shape for maximum torque density and minimum torque ripple starting from an existing motor or a preliminary design. Index Terms--Finite element method (FEM), response surface methodology (RSM), synchronous reluctance motor (SynRM), torque ripple.

In this paper, a method to improve radiation characteristics of a finite planar array by introducing small perturbations in patch antenna locations is presented. The dependence of the radiation patterns of an individual antenna element in the array is determined for a restricted range of patch locations relative to the array substrate edge and the neighboring antennae elements. A polynomial interpolation function is utilized to map the geometry variables of each antenna to the corresponding radiation pattern. Optimization schemes are then applied to determine the excitation amplitude, phase, and relative spacing of each antenna. Index Terms--Method of moments (MoMs), model-based parameter estimation, optimization, planar arrays.

In this paper, the finite element algorithm is implemented to calculate field and temperature variation in high voltage direct current cylindrical cables. Such cables contain joins and interconnects which result in physical discontinuities where strong fields may be present, resulting in dielectric breakdown during power switching events. To minimize the possibility of catastrophic failure, design sensitivity analysis is applied to determine a geometry that minimizes the field variation within the region of interest. Since the material properties in these systems demonstrate both temperature and field dependencies, the resulting nonlinearities are considered in the formulation. Index Terms--Coupled problems, design sensitivity, finite element method, high voltage direct current (HVDC) insulation.

In this paper, an adaptive frequency sampling technique is applied to the moment method for the analysis of microstrip filters and patch antennae. The analysis of microstrip low-pass filter and patch antenna in the frequency domain has been usually done with uniform frequency step. An adaptive frequency sampling technique can significantly reduce the time taken for the analysis through the frequency range without reducing the accuracy of the results. Index Terms--Adaptive sampling, method of moments, microwave devices, planar structures.

This paper demonstrates new systematic approaches to equivalent circuit model extraction for defected ground structure (DGS) directly from full-wave frequency domain simulation. The DGS circuits being modeled may be either lossy or lossless. Adaptive frequency sampling (AFS) is used to minimize the computational effort of electromagnetic (EM) simulation while critically assisting in determining the cutoff frequency and attenuation pole location of the DGS circuits. A simple circuit model for lossy DGS circuits without any optimization of lumped element component values is presented. Furthermore, lossless circuit model relative complex along with a determined starting point of optimization of lumped element values is also presented in detail. The overall results are an efficient and accurate means to produce the complete equivalent models of DGS circuit for the design of various RF and microwave circuits such as oscillators that may require the high accurate nonlinear design procedures. Index Terms--Defected ground structure (DGS), equivalent circuit model, full-wave frequency domain simulation, oscillator.

Left-handed material (LHM) exhibiting negative permittivity and negative permeability in certain band has dispersive medium property varying with frequency. The effective permittivity and permeability function of this material have a similar form of Lorentz material model. Piecewise linear recursive convolution (PLRC) technique for finite difference time domain (FDTD) method is applied to simulate the propagation characteristic of LHM effectively. Modified anisotropic perfectly matched layer (APML) is proposed for absorbing boundary condition of LHM. The simulation results show narrow pass band in the stop band where LHMs have double negative properties. Index Terms--Anisotropic perfectly matched layer (APML), dispersive medium, double negative (DNG), finite difference time domain (FDTD), left-handed material (LHM), metamaterial, piecewise linear recursive convolution (PLRC), split ring resonator (SRR).

This paper deals with a method for obtaining the transient internal voltage distribution of a transformer. It is essential to consider the frequency-dependent effects of internal capacitance, inductance, and resistance in order to analyze the transient characteristics of a transformer. Frequency-dependent inductance and resistance are obtained from an analytical method and the values match welt with the experimental ones. The numerical results of internal transient voltage of a transformer show good agreement with the experimental results from the literature. Index Terms--Modal analysis, transformer, transient analysis.

To improve computational accuracy and efficiency, the flux-corrected transport scheme on an unstructured grid is proposed as a method of local field approximation plasma display panel (PDP) modeling. The discharge of a PDP macrocell is simulated and the results are presented. After the discussion about the waveform of current and striation phenomena, it is shown that the accuracy of the proposed method is superior to that of a conventional method. Index Terms--Discharge simulation, flux-corrected transport, plasma display panel (PDP), unstructured grid.

The shapes of waveguide structures are optimized for the uniform electromagnetic field illumination. The vector finite element method is used as an analysis method. As the design algorithm, we employ the shape optimization with a design sensitivity analysis. Performance measure function representing the field uniformity is defined in this paper and used for the calculation of the design sensitivity. The design procedure is applied to the H-plane shape optimization in the rectangular cavity structure with a rectangular waveguide feeder and the E-plane shape optimization in the two plates waveguide. Index terms - uniform field distribution, optimization, cavity, finite element method

Digital magnetoresistance (MR) properties of the sheet and patterned NiFeCo/Cu/Co spin-valve trilayer films were characterized. As reported in our previous publication, NiFeCo/Cu/Co films showed strong in-plane uniaxial magnetic anisotropy on a special template, 4 [degrees] tilt-cut Si(111) wafer with a 50 [Angstrom] of Cu underlayer, without any externally applied magnetic field during the deposition. In order to demonstrate the industrial applicability of NiFeCo/Cu/Co films on the specific templates for digital MR devices, dynamic and static MR measurements were performed along the easy axis of the films. For dynamic MR measurement, NiFeCo/Cu/Co films were optimized with respect to Cu spacer thickness and patterned into a stripe of high aspect ratio of 1: 200 (height: width) where the easy axis of the film was aligned along the height direction. After patterning, uniaxial magnetic anisotropy was maintained, and MR properties showed no appreciable degradation. Therefore, it was believed that the special template is effective for the uniaxial magnetic anisotropy of NiFeCo/Cu/Co films and useful in the industrial applications. MR properties of sheet and patterned trilayer films suggest that these NiFeCo/Cu/Co spin valves on the specific templates are good candidates for digital MR devices such as magnetoresistive random access memory (MRAM). Index Terms - Digital magnetoresistance, 4 [degrees] tilt-cut Si (111) wafer, NiFeCo/Cu/Co spin-valve trilayers, uniaxial magnetic anisotropy.

This paper employed the spectral domain method of moment for the calculation of the current distribution and inductance of the spiral inductor on silicon multilayer structures. We used FFT (Fast Fourier Transform) in the calculation of the infinite 2-dimensional integrals and 'Divided FFT' in the case of the very small size analysis model. Using this algorithm, the computation time can be reduced considerably compared with the direct integration. The computed inductance was compared with what measured to show the validation of the formulation.

This paper presents an optimum design method for an eigenvalue system in electromagnetics. For the spurious mode free analysis of the eigenvalue system, vector finite element method is adopted. In order to obtain the gradient of the objective function, which is given as a function of eigenvalues, with respect to the design variables, the eigenvalue design sensitivity analysis is proposed. The proposed method is applied to lower the cut-off frequency and to broaden the frequency range of the ridged waveguides. The numerical examples of the ridged waveguide designs show the validity of the proposed method.

Magnetic anisotropy of Co and NiFe thin films was investigated on 9 degree off Si(100) and 4 degree off Si(111) surfaces and compared. Both films showed in-plane uniaxial anisotropy on the two vicinal surfaces, but the directions of easy axis were so different that Co thin films showed the same easy axis on the two vicinal surfaces along the surface step direction, and NiFe thin films exhibited an easy axis along the steps on the 9 degree off Si(100) surfaces but perpendicular to the step direction in the film plane on 4 degree off Si(111) surfaces. From X-ray pole figure patterns, magnetoelastic effects rather than magnetocrystailine are thought to play a key role in the uniaxial magnetic anisotropy of Co and NiFe thin films on vicinal surfaces. Also, varicus R-H curves of NiFe/Cu/Co spin valves on the two vicinal surfaces are believed to increase the potential of vicinal substrates for industrial applications. Index Terms -- Co and NiFe thin films, vicinal Si surfaces, uniaxial anisotropy, X-ray pole figure, NiFe/Cu/Co spin valves.

In this paper, the use of adaptive mesh generation is proposed as a method of streamer simulation. The error estimation scheme is also presented. The employed adaptive scheme can refine the mesh where needed. In addition, it is possible to coarsen the unnecessarily dense mesh. For a numerical example, the propagation of a negative streamer was simulated and the results were shown. Through the adaptive mesh generation, we can obtain not only higher resolution but also more efficient grid distribution with smaller number of grids. Index Terms--Adaptive mesh generation, finite element method, flux-corrected transport, streamer.

Deals with a study which presented an adaptive mesh generator based on nodal errors. Details on the implementation of the mesh generator with nodal spacing values; Analysis through mesh generation; Methods to estimate computational errors.

Presents information on a study which investigated the proposed Finite Element Method combined with Flux-corrected Transport (FCT) algorithm as a method to simulate streamer corona. Equations of streamer dynamics; Concept of FCT; Numerical example; Conclusions.