Search results

1 – 3 of 3
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 11 November 2013

Ugo d'Elia, Giuseppe Pelosi, Stefano Selleri and Ruggero Taddei

A design procedure for multi-layer absorbers based on carbon nanotubes (CNT) frequency selective surfaces (FSS) sheets is here developed. The paper aims to discuss there issues…

182

Abstract

Purpose

A design procedure for multi-layer absorbers based on carbon nanotubes (CNT) frequency selective surfaces (FSS) sheets is here developed. The paper aims to discuss there issues.

Design/methodology/approach

Single layer FSS are first analyzed via finite element (FE). Then equivalent sheets admittances are extracted in a transmission line model. Neural networks (NNs) interpolation over this data and subsequent multi-objective genetic algorithm (GA) based optimizations are then performed to design multiple layers absorbing structures. Designs are finally validated via full wave FEM simulations.

Findings

In this paper, some absorbing structures made of three or four FSS sheets with total thicknesses around 6 mm are synthesized.

Research limitations/implications

NNs' accuracy used in the equivalent model can be refined with further training.

Practical implications

Low profile absorbing materials are of relevant industrial interest both for radar cloaking and anechoic chambers.

Originality/value

The transmission line model combined with NNs and GA optimization is capable of speeding up the design procedure with respect to a conventional full-wave FEM approach.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 32 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Access Restricted. View access options
Article
Publication date: 14 November 2008

Giacomo Guarnieri, Giuseppe Pelosi, Lorenzo Rossi and Stefano Selleri

The paper's aim is to devise a fast method for microwave waveguide filter permittivity tolerance analysis.

199

Abstract

Purpose

The paper's aim is to devise a fast method for microwave waveguide filter permittivity tolerance analysis.

Design/methodology/approach

A 2D finite elements (FEs) formulation is combined via a Schur complement‐based domain decomposition (DD) technique to reduce the tolerance affected part of the analysis to a smaller domain.

Findings

The paper shows how to combine FEs and DD in an efficient way for material parameters tolerance analyses in microwave waveguide filters, showing speedup results.

Research limitations/implications

The formulation here presented is 2D but can be easily extended to 3D.

Originality/value

The application of DD to solve numerically large problem is well‐known, the idea and organization of the algorithm to allow iteration on parameter values on a single sub‐domain is here proposed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Access Restricted. View access options
Article
Publication date: 14 November 2008

S. Selleri and A. Cucinotta

The aim of this paper is to show the effectiveness of the finite element method (FEM) to study the properties of different kinds of photonic crystal fibers (PCFs), presenting…

541

Abstract

Purpose

The aim of this paper is to show the effectiveness of the finite element method (FEM) to study the properties of different kinds of photonic crystal fibers (PCFs), presenting results which highlight the FEM flexibility, exploited according to the particular PCF feature under investigation.

Design/methodology/approach

The FEM has been applied to a new emerging class of optical fibers, the so‐called PCFs, also known as microstructured or holey fibers.

Findings

It has been shown how to design and customize the PCF cross‐section to achieve desired values of dispersion, confinement loss, nonlinear or amplification properties. Reported examples prove the FEM ability to deal with complex geometries, arbitrary refractive index steps and distribution, and to be integrated with other approaches for a better and accurate analysis of the considered fiber.

Research limitations/implications

Limitation in the FEM use can be given by the required computation effort in terms of memory occupancy and time, even if computational power of modern workstations can attenuate this aspect.

Practical implications

The FEM can be a very powerful tool to investigate and design actual structures to be used in several fields, as telecom, sensing, fiber lasers, spectroscopy.

Originality/value

The novelty of the paper is given by the exploitation of the FEM feature to design a new emerging class of optical fibers, considering all numerical aspects given by the unusual characteristics of the domain and problem under investigation.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

1 – 3 of 3
Per page
102050