Analyzing the Internal Impedance of a Source

In many simulations, a source isn’t just an ideal voltage; it often includes an internal impedance that accounts for the physical characteristics of the feedline or generator. You can analyze how much power is lost internally versus how much is delivered to the antenna by following these steps:

1. Locate the Source: Right-click on the wire where the source is positioned to open the pop-up menu.
2. Open the “List Currents” Toolbar: Select List Currents to activate the corresponding toolbar.
3. Select the Source Segment: Use the slider (or the 50% button if centered) to highlight the segment containing the source.
4. Open the Source List: Click the Source List button. This opens a dialog box that focuses specifically on the internal behavior of the source (Fig. 1).

Evaluating Internal Parameters

The Source List dialog provides a frequency-by-frequency breakdown of:

• Internal Current & Voltage: The electrical values specifically across the source’s internal impedance.
• Internal Power: Useful for determining if the generator is properly matched to the load (the antenna).

To visualize these trends, select an item from the list in the upper-right corner and click Plot to view it in AN-XY Chart.