This document describes the process of, and measurements taken during the crosstalk experiment; Part of the EV6 Hardware Implementation course at the University of applied sciences Utrecht.
Two conductors running parallel to each other can cause crosstalk, this is when the signal on one line induces a signal on the other line. This can cause signal integrity issues and can even cause the transmission hardware to malfunction.
This experiment will be performed on a pre-built contraption consisting of three wires above an metal plate connected to signal ground, two of which will be used. By putting a signal on one wire and measuring the resulting signal on the other, the difference between capacitive and inductive crosstalk can be observed, as well as the effect of different terminators on the signal and crosstalk.
\subsection{Objective}
The purpose of the experiment is to learn the difference between capacitive and inductive crosstalk and how different terminators affect the signal and crosstalk. Using the results of the experiment the mutual self-inductance and coupling capacitance of the setup should be determined.
\section{Methodology}
The lab manual does not provide a clear methodology for the experiment, requiring the students to setup a measurement plan themselves. We determined the following measurements would be required to determine the inductance and capacitance of the setup: % yes we determined this right before we did them so that counts as a plan right?
\begin{itemize}
\item Near and far side of the interfered conductor while the signal conductor is not terminated.
\item Near and far side of the interfered conductor while the signal conductor is shorted to ground.
\item Near and far side of the interfered conductor while the signal conductor is terminated characteristically.
\end{itemize}
The lab manual includes Figure \ref*{fig:setup_ee} which describes the electrical properties of the setup.
Since the experiment setup includes a series 180 $\Omega$ resistor, the characteristic impedance would be the sum of the impedance of the resistor and the impedance of the function generator. This would make the characteristic impedance 230 $\Omega$. The setup did include a terminator of 230 $\Omega$, but it seemed to be somewhat sketchy, being hand made, and we were not sure if it was part of the setup at all. We decided to use both the 50 $\Omega$ and 230 $\Omega$ terminators to be sure and to see if there was any difference in the results.
\subsection{Equipment}
The following equipment will be used during the experiment:
\begin{itemize}[beginpenalty=10000] % This is to prevent the list from breaking across columns, but it doesn't do shit
The results expected for the different types of crosstalk are described in the following sections.\\
% CITATION NEEDED
\textbf{Capasive crosstalk}\\
Capacitive crosstalk is caused by the electric field of the signal conductor inducing a voltage on the interfered conductor. The crosstalk should be higher on the near side of the interfered conductor than on the far side. When the signal conductor is terminated, the voltage on the signal conductor is practically zero, making the capacitive crosstalk minimal. When the signal conductor is not terminated, the crosstalk should be at its maximum.\\% Something smart about phase shfting here
\textbf{Inductive crosstalk}\\
Inductive crosstalk is caused by the magnetic field of the signal conductor inducing a voltage on the interfered conductor. The crosstalk should be higher on the far side of the interfered conductor than on the near side. When the signal conductor is terminated, the crosstalk should be at its maximum. When the signal conductor is not terminated, the crosstalk should be minimal.\\
When the signal conductor is terminated with a characteristic terminator, the resulting will be a combination of the capacitive and inductive crosstalk since the voltage is not shorted and there is some current flowing through the signal conductor; Causing both the electric and magnetic field to induce a voltage on the interfered conductor.
