AT Card
This card defines a voltage source that is applied to a voxel mesh in connection with a finite difference time domain (FDTD) method.
On the Source/Load tab, in the Sources on
geometry group, click the 
Voltage source
icon. From the drop-down list, click the 
Geometry source (AT) icon.
Figure 1. The AT - Geometry source on port dialog.
Parameters:
- Source name
- The name of the excitation to be defined.
- Name of port definition
- The name of the port.
- New source
- A new excitation is defined which replaces all previously defined excitations.
- Add to sources
- A new excitation is defined which is added to the previously defined excitations.
- Magnitude of source (V)
- Magnitude of the voltage source in V.
- Phase of source (degrees)
- Phase of the voltage source in degrees.
- Reference impedance (Ohm)
- The reference impedance of the excitation is used for S-parameter calculations and is the reference impedance used for realised gain calculations. It is also the default reference impedance used to calculate and display the reflection coefficient in POSTFEKO. If this field is empty or 0 in an S-parameter calculation, the value specified at the SP card is used. For realised gain and reflection coefficient calculations, 50 Ohm will be assumed when the field is empty or 0.