A Generalized Node for Embedding Subwavelength Objects Into 3-D Transmission-Line Models

TLM node with arbitrary embedded objects

“…One approach that has already received significant attention is to use special nodes to describe fine features whose responses model the effect of the sub cell structure within an otherwise coarse mesh model [1][2][3][4][5][6]. A variety of examples for EMC predictions have already been shown using this technique.…”

“…Recently a 2D node that embeds an arbitrary number of wires of varying dimensions and material characteristics coupled by their near fields has been described [5]. The important case of short lengths of thin wire which are obliquely oriented to the faces of 3D cells has also been considered [6] making it possible to simulate 3D piecewise linear models of arbitrarily routed curved wires in TLM. The embedding process demonstrated in all the above examples exploits the availability of a suitable set of local analytic solutions to Maxwell's equations in the vicinity of the enclosed objects.…”

General treatment of tlm node with embedded structures

“…By its very nature EMC analysis often requires consideration of systems characterized by many different physical scales, such as when thin wires, gaps and slots are present in large structures. In the Transmission Line Modelling (TLM) method of analysis, nodes that enable fine structures to be embedded within them have been demonstrated for special cases where the fields local to the object may be expanded in terms of analytically known local solutions [1][2][3][4][5][6]. The approach presented here differs in that it is based on purely numerical calculations of these local expansion and it therefore allows arbitrary structures for which analytical representations of local fields are unavailable, to be incorporated into TLM nodes.…”

“…In order to reliably characterise such a system these features must be included in the simulation models. The classical approach using dense meshing is often inefficient, if not beyond the available computational resources and therefore over the years substantial effort has been made to develop more suitable techniques.One approach to describing fine features that has already been given much attention is to use a special node modelling the effect of sub cell structure into a coarse mesh model [1][2][3][4][5][6].A variety of examples for EMC predictions have already been shown using such techniques.A node with a straight metal wire placed in the centre has been demonstrated for the 2D [1,2] and 3D TLM methods [3]. Further extension in the 2D case has been demonstarted, mapping a node containing an arbitrarily positioned thin metal or dielectric post within a single cell into a TLM network [4].…”

“…One approach to describing fine features that has already been given much attention is to use a special node modelling the effect of sub cell structure into a coarse mesh model [1][2][3][4][5][6].…”