The Metrics Tab

The Metrics tab in the AN-SOF main window (Fig. 1) displays a table with the primary metrics for a transmitting antenna, including:

• Input Impedance (Z_in = R_in + jX_in)
• VSWR
• S₁₁
• Directivity
• Gain
• Radiation Efficiency
• Horizontal (H) and Vertical (V) Front-to-Rear (F/R) and Front-to-Back (F/B) Ratios

This table is automatically populated only when the wire structure is excited by a discrete source. It will not be filled if the excitation is an incident wave.

The tabulated metrics persist until a new calculation is performed, allowing you to reference them at any time, even when making changes to the project. To export these metrics to a CSV file, click the Export Frequency Metrics button on the toolbar (Fig. 1).

Interactive Column Headers

The column headings, from Rin through F/B V, are interactive buttons (see Fig. 1). Clicking on them displays rectangular plots, where the data in the column is plotted as a function of frequency.

• Click the “Freq.” column header to display the input impedance (Z_in = R_in + jX_in) in a Smith Chart. By default, this is the input impedance at the antenna feedpoint.
• If the antenna has a feeder and/or tuner connected to its terminals, the impedance seen at the feeder input or tuner input can also be tabulated in the Metrics tab. These can be plotted against frequency in rectangular or Smith charts by clicking the corresponding column headers.

Plotting Impedance at Different Points

1. Navigate to the Plots tab > “Zin” box (see Fig. 2) and choose between Antenna, Feeder, or Tuner.
2. Go to the Metrics tab, where R_in, X_in, VSWR, and S₁₁ will be tabulated for the selected option (antenna, feeder, or tuner input).
3. Click the header buttons as indicated in Fig. 1 to plot these metrics against frequency.