Near-field calculation based on the T-matrix method with discrete sources

2011 ◽  
Vol 112 (14) ◽  
pp. 2384-2394 ◽  
Author(s):  
Carlo Forestiere ◽  
Giovanni Iadarola ◽  
Luca Dal Negro ◽  
Giovanni Miano
Keyword(s):  
Matrix Method ◽  
Near Field ◽  
Field Calculation ◽  
T Matrix

scholarly journals Mind the gap: testing the Rayleigh hypothesis in T-matrix calculations with adjacent spheroids

2020 ◽  
Author(s):  
D Schebarchov ◽  
EC Le Ru ◽  
Johan Grand ◽  
Baptiste Auguié
Keyword(s):  
Cross Sections ◽  
Electromagnetic Scattering ◽  
Matrix Method ◽  
Near Field ◽  
Local Fields ◽  
Nonspherical Particles ◽  
Multiple Particles ◽  
Numerical Instabilities ◽  
T Matrix ◽  
Rayleigh Hypothesis

The T-matrix framework offers accurate and efficient modelling of electromagnetic scattering by nonspherical particles in a wide variety of applications ranging from nano-optics to atmospheric science. Its analytical setting, in contrast to purely numerical methods, also provides a fertile ground for further theoretical developments. Perhaps the main purported limitation of the method, when extended to systems of multiple particles, is the often-stated requirement that the smallest circumscribed spheres of neighbouring scatterers not overlap. We consider here such a scenario with two adjacent spheroids whose aspect ratio we vary to control the overlap of the smallest circumscribed spheres, and compute far-field cross-sections and near-field intensities using the superposition T-matrix method. The results correctly converge far beyond the no-overlap condition, and although numerical instabilities appear for the most extreme cases of overlap, requiring high multipole orders, convergence can still be obtained by switching to quadruple precision. Local fields converge wherever the Rayleigh hypothesis is valid for each single scatterer and, remarkably, even in parts of the overlap region. Our results are validated against finite-element calculations, and the agreement demonstrates that the superposition T-matrix method is more robust and broadly applicable than generally assumed.

scholarly journals Mind the gap: testing the Rayleigh hypothesis in T-matrix calculations with adjacent spheroids

2020 ◽  
Author(s):  
D Schebarchov ◽  
EC Le Ru ◽  
Johan Grand ◽  
B Auguié
Keyword(s):  
Cross Sections ◽  
Electromagnetic Scattering ◽  
Matrix Method ◽  
Near Field ◽  
Local Fields ◽  
Nonspherical Particles ◽  
Multiple Particles ◽  
Numerical Instabilities ◽  
T Matrix ◽  
Rayleigh Hypothesis

The T-matrix framework offers accurate and efficient modelling of electromagnetic scattering by nonspherical particles in a wide variety of applications ranging from nano-optics to atmospheric science. Its analytical setting, in contrast to purely numerical methods, also provides a fertile ground for further theoretical developments. Perhaps the main purported limitation of the method, when extended to systems of multiple particles, is the often-stated requirement that the smallest circumscribed spheres of neighbouring scatterers not overlap. We consider here such a scenario with two adjacent spheroids whose aspect ratio we vary to control the overlap of the smallest circumscribed spheres, and compute far-field cross-sections and near-field intensities using the superposition T-matrix method. The results correctly converge far beyond the no-overlap condition, and although numerical instabilities appear for the most extreme cases of overlap, requiring high multipole orders, convergence can still be obtained by switching to quadruple precision. Local fields converge wherever the Rayleigh hypothesis is valid for each single scatterer and, remarkably, even in parts of the overlap region. Our results are validated against finite-element calculations, and the agreement demonstrates that the superposition T-matrix method is more robust and broadly applicable than generally assumed.

scholarly journals Mind the gap: testing the Rayleigh hypothesis in T-matrix calculations with adjacent spheroids

2020 ◽  
Author(s):  
D Schebarchov ◽  
EC Le Ru ◽  
Johan Grand ◽  
Baptiste Auguié
Keyword(s):  
Cross Sections ◽  
Electromagnetic Scattering ◽  
Matrix Method ◽  
Near Field ◽  
Local Fields ◽  
Nonspherical Particles ◽  
Multiple Particles ◽  
Numerical Instabilities ◽  
T Matrix ◽  
Rayleigh Hypothesis

The T-matrix framework offers accurate and efficient modelling of electromagnetic scattering by nonspherical particles in a wide variety of applications ranging from nano-optics to atmospheric science. Its analytical setting, in contrast to purely numerical methods, also provides a fertile ground for further theoretical developments. Perhaps the main purported limitation of the method, when extended to systems of multiple particles, is the often-stated requirement that the smallest circumscribed spheres of neighbouring scatterers not overlap. We consider here such a scenario with two adjacent spheroids whose aspect ratio we vary to control the overlap of the smallest circumscribed spheres, and compute far-field cross-sections and near-field intensities using the superposition T-matrix method. The results correctly converge far beyond the no-overlap condition, and although numerical instabilities appear for the most extreme cases of overlap, requiring high multipole orders, convergence can still be obtained by switching to quadruple precision. Local fields converge wherever the Rayleigh hypothesis is valid for each single scatterer and, remarkably, even in parts of the overlap region. Our results are validated against finite-element calculations, and the agreement demonstrates that the superposition T-matrix method is more robust and broadly applicable than generally assumed.

scholarly journals Numerically efficient version of the T-matrix method

2001 ◽  
Vol 80 (3-4) ◽  
pp. 385-393 ◽  
Author(s):  
A.G. Ramm
Keyword(s):  
Matrix Method ◽  
T Matrix

scholarly journals Installation Uncertainty of Field Level Calculation around a Base Station Antenna

2007 ◽  
Vol 3 (2) ◽  
pp. 115
Author(s):  
Antonio Šarolić ◽  
Borivoj Modlic
Keyword(s):  
Hazard Analysis ◽  
Near Field ◽  
Three Dimensional ◽  
Real Life ◽  
Base Station ◽  
Radiation Hazard ◽  
Specific Situation ◽  
Field Calculation ◽  
Single Antenna ◽  
Level Calculation

In the near field, the antenna pattern provided by the antenna manufacturer is generally not applicable, or shouldbe considered with caution, even for the single antenna in free space. In the real life, antenna is often surrounded by other conductive objects in the immediate vicinity. These objects tend to distort the antenna radiation pattern. Since the electromagnetic field calculation for the coverage or radiation hazard analysis depends on the three-dimensional antenna gain, this effect should be taken into account. This paper suggests the use of "installation uncertainty" that should be added to the field calculation. The amount of this quantity depends on the installation geometry and can be calculated numerically for a specific situation. This paper shows the results of numerical calculations for some typical antenna installation geometries.

scholarly journals Convergence of the iterative T-matrix method

2020 ◽  
Vol 28 (19) ◽  
pp. 28269
Author(s):  
Michael Kahnert ◽  
Tom Rother
Keyword(s):  
Matrix Method ◽  
T Matrix

A fast and flexible library-based thick-mask near-field calculation method

2015 ◽  
Author(s):  
Xu Ma ◽  
Jie Gao ◽  
Xuanbo Chen ◽  
Lisong Dong ◽  
Yanqiu Li
Keyword(s):  
Calculation Method ◽  
Near Field ◽  
Field Calculation
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