Changes

==Defining the Gap Source Definitionand Project Observables ==

A dipole antenna can be excited using a gap source, which is the simplest source type in the [[MoM3D Module|MoM3D ModuleEM.Libera]]. A gap source can be placed on a line object (line gap), or on a rectangle strip object (strip gap) or on a box object (box gap). The line gap is intended for Wire MoM simulation, while the strip and box gaps are gap is intended for Surface MoM simulation. A line gap source creates an infinitesimal gap on the line and connects a voltage source across the gap. To define a gap source, right-click on the <b>Gap SourceSources</b> item in the “Sources” section of the Navigation Treenavigation tree, and select <b>Insert New Line Gap Source…</b> The Line Gap Source Dialog opens up.

The drop-down dropdown list labeled <i>Line Object</i> displays all the line objects in the project workspace. In this project, there is only one line object, which is selected by default. A new gap source is placed at the center of the host line object by default. The location of the source can be changed via the <i>'''Offset</i> ''' parameter of the dialog. We will leave this at 75 Keep the default value for this tutorial, as we want to test a center-fed dipole. You can also change the direction of the gap source. Your gap source will have an has a default <b>Amplitude</b> of 1V and a default zero <b>Phase</b>. You will see the gap source in the middle of the line, represented by two parallel disks.

[[Image:WMOM3MOMTUT3 4.png|thumb|350px450px|The Gap sourceSource's property dialog.]]</td><td>[[Image:WMOM4.png|thumb|200px|The drawn Line object with the gap source placed at its center.]]