A Volume PEEC Formulation Based on the Cell Method for Electromagnetic Problems From Low to High Frequency

2019 ◽  
Vol 67 (12) ◽  
pp. 7452-7465 ◽  
Author(s):  
Riccardo Torchio
Keyword(s):  
High Frequency ◽  
Electromagnetic Problems ◽  
Cell Method

scholarly journals Coupling the Cell Method with the Boundary Element Method in Static and Quasi–Static Electromagnetic Problems

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1426
Author(s):  
Federico Moro ◽  
Lorenzo Codecasa
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Hybrid Approach ◽  
Iterative Solution ◽  
Third Order ◽  
Electromagnetic Problems ◽  
Cell Method ◽  
Hybrid Approaches ◽  
Complex Topology ◽  
Element Method

A unified discretization framework, based on the concept of augmented dual grids, is proposed for devising hybrid formulations which combine the Cell Method and the Boundary Element Method for static and quasi-static electromagnetic field problems. It is shown that hybrid approaches, already proposed in literature, can be rigorously formulated within this framework. As a main outcome, a novel direct hybrid approach amenable to iterative solution is derived. Both direct and indirect hybrid approaches, applied to an axisymmetric model, are compared with a reference third-order 2D FEM solution. The effectiveness of the indirect approach, equivalent to the direct approach, is finally tested on a fully 3D benchmark with more complex topology.

Nonlinear coupled thermo-electromagnetic problems with the cell method

2006 ◽  
Vol 42 (4) ◽  
pp. 991-994 ◽  
Author(s):  
M. Bullo ◽  
F. Dughiero ◽  
M. Guarnieri ◽  
E. Tittonel
Keyword(s):  
Electromagnetic Problems ◽  
Cell Method

scholarly journals A Hybrid Asymptotic-FVTD Method for the Estimation of the Radar Cross Section of 3D Structures

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1388 ◽  
Author(s):  
Alessandro Fedeli ◽  
Matteo Pastorino ◽  
Andrea Randazzo
Keyword(s):  
Cross Section ◽  
High Frequency ◽  
Current Method ◽  
Radar Cross Section ◽  
Hybrid Technique ◽  
Electromagnetic Problems ◽  
Large Structures ◽  
Full Wave ◽  
Scattering Effects ◽  
Wave Technique

The Finite Volume Time-Domain (FVTD) method is an effective full-wave technique which allows an accurate computation of the electromagnetic field. In order to analyze the scattering effects due to electrically large structures, it can be combined with methods based on high-frequency approximations. This paper proposes a hybrid technique, which combines the FVTD method with an asymptotic solver based on the physical optics (PO) and the equivalent current method (ECM), allowing the solution of electromagnetic problems in the presence of electrically large structures with small details. Preliminary numerical simulations, aimed at computing the radar cross section of perfect electric conducting (PEC) composite objects, are reported in order to evaluate the effectiveness of the proposed method.

A Novel Neural Network Cell Method for Solving Nonlinear Electromagnetic Problems

2021 ◽  
pp. 2100216
Author(s):  
Gaojia Zhu ◽  
Longnv Li ◽  
Weinong Fu ◽  
Ming Xue ◽  
Tao Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Network Cell ◽  
Electromagnetic Problems ◽  
Cell Method

scholarly journals A Novel Neural Network Cell Method for Solving Nonlinear Electromagnetic Problems (Adv. Theory Simul. 12/2021)

2021 ◽  
Vol 4 (12) ◽  
pp. 2170030
Author(s):  
Gaojia Zhu ◽  
Longnv Li ◽  
Weinong Fu ◽  
Ming Xue ◽  
Tao Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Network Cell ◽  
Electromagnetic Problems ◽  
Cell Method

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

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