\section{Spice cable bundle model structure} \label{spice_cable_bundle_model_structure}

Figure \ref{fig:spice_cable_bundle_model_structure} shows the structure of the spice cable bundle model with a termination network. The termination network is an arbitrary network to be constructed by the user and does not concern us here. The spice cable bundle model consists of a number of cascaded elements. The major elements are (in order from the model terminals inwards)

\begin{enumerate}
\item d.c. conductor resistance
\item Domain decomposition network
\item Modal decomposition network
\item Souces to include transfer impedance and incident field excitation
\item Method of characteristics delay lines
\item Transfer impedance delay lines
\item Incident field delay lines
\end{enumerate}

\begin{figure}[h]
\centering
\includegraphics[scale=0.65]{./Imgs/block_model.eps}
\caption{Structure of the spice cable bundle model}
\label{fig:spice_cable_bundle_model_structure}
\end{figure}

\clearpage

\subsection{Terminology} \label{terminology}

In discussing the spice cable bundle model we require a clear terminology so as to allow unambiguous reference to particuar sections of the model. 

Cable numbering always relates to the numbering of the cables within a bundle and is specified by the order in which they are
included in the cable\_spec file.

Within a cable there is a local numbering system for cables and domains within a cable e.g for a coaxial cable the inner wire is local\_conductor 1
and the shield is local conductor 2. Similarly the inner coaxial domain is domain 1 and the external domain is domain 2.

Once a cable bundle is built a global numbering is introduced.

We adopt the terminology in table \ref{table:terminology} both in this document and in the software itself:

\begin{table}[h]
\begin{center}
\begin{tabular}{ | p{4cm} | p{3cm} | p{5cm} |}
\hline
Name &  parameters & Description \\ \hline

global terminal conductor & conductor number  & The global conductor number in the cable bundle \\ \hline
global domain conductor   & domain number, conductor number  & The global conductor number in a particular domain \\ \hline
local cable conductor   & cable number  & The local conductor number in a particular cable. This is fixed for each cable type\\ \hline
global cable conductor   & cable number, conductor number  & The global conductor number in a particular cable \\ \hline
local cable domain   & cable number  & The local domain number in a particular cable. This is fixed for each cable type \\ \hline
global cable domain   & cable number, conductor number  & The global domain number in a particular cable \\ \hline
    \end{tabular}
\end{center}
\caption{Spice cable bundle model terminology} 
\label{table:terminology}
\end{table}

\vspace{5mm}


\clearpage