How to do I integrate power over a specific frequency window?

1)      Take a scan using the lineardata command. It’s important to retrieve the data in units of mW rather than dBm using this command:


2)      Discard any data points outside the integration window so that you are left with only data points within the window. In this example, an 800MHz window is selected from the data:

3)      Note that the units of the first column is MHz. The units of the second column is technically mW/150 MHz; that is power in mW within a 150 MHz window (although it is incorrectly labelled mdBm).

4)      The third and fourth columns are the powers within the X and Y polarizations. You can discard them so you are left with:

5)      Perform a numerical integration by adding up all the power values and then multiply by the frequency step (It will be either 20 MHz or 100 MHz depending on the scan setting). You can think of this as a Riemann Sum. This gives you a single power value in units given by the multiplication of the X-Axis unit and Y-Axis unit: i.e. MHz * (mW/150MHz) = mW/150.

6)      In the above example, adding up all the power values gives you 0.377. Multiplying by the frequency step of 100MHz gives you 37.7 in units of mW/150.

7)      Divide by 150 to convert the units to mW. This gives you 0.251 mW of total power contained within the above trace data.