The Plots Tab

Select the Plots tab in the AN-SOF main window to visualize the plots of the main results for a transmitting antenna as a function of frequency, as shown in Fig. 1. These results are derived from the table in the Metrics tab.

Plot Layout

• Left Column: Displays the real and imaginary parts of the input impedance (Z_in = R_in + jX_in) and the VSWR/S₁₁.
• Right Column: Shows the antenna gain in dBi and the Front-to-Rear (F/R) and Front-to-Back (F/B) ratios in dB.

The plots are aligned vertically to facilitate easy comparison.

Customizing Plots

Use the controls on the right side of the Plots tab to adjust various aspects of the graphics, including:

• Line thickness.
• Visualization of points and marks.
• Scales and axes.
• Selection between VSWR or S₁₁.
• Choice between Horizontal (H) or Vertical (V) F/R and F/B ratios.

Each plot can be maximized by clicking the Maximize checkbox located in its upper-right corner.

You can customize the scales of the plots displayed in the Plots tab using the Preferences window.

To access these settings, go to the main menu and select Tools > Preferences (or click the gear icon on the toolbar), then select the “Plots” tab in the Preferences dialog box (Fig. 2). From there, you can enable or disable Auto (automatic scaling) and Log (logarithmic scale versus linear scale), as well as set the minimum value, increment, and maximum value for all vertical and horizontal axes.

💡 Tip

VSWR plots typically use a logarithmic scale. To set this up, uncheck Auto, check Log, and set Min = 1, Inc = 1, and Max = 10.

Input Impedance and VSWR/S₁₁ Options

The input impedance and VSWR/S₁₁ plots can represent:

• The antenna input impedance.
• The feeder + antenna input impedance.
• The tuner input impedance.

The tuner and feeder can be configured in their corresponding tabs next to the Metrics tab. Whenever a tuner or feeder parameter is changed, the recalculated results in the Metrics and Plots tabs can be refreshed by selecting the desired option under the Zin box (highlighted in Fig. 1).

Tuner Option

If the Tuner option is selected:

• The input impedance of the tuner will be displayed.
• If the tuner is connected to a combination of feeder + antenna, the input impedance and VSWR/S₁₁ of the tuner + feeder + antenna system will be displayed.