How do I obtain 3dB Bandwidth of a bandpass Filter?
Use the marker() function in output equations to calculate the 3D bandwidth of a filter.
- Add two Auto Search markers. Right click inside the graph > Add Auto Search Marker, select Value, and enter -3. Click somewhere on the left side of the trace to add the first 3dB point.
- Similarly add another -3db marker on the right side of the trace for second 3dB point
- In Output Equations, add the following equations to get the values of markers
BW_3dB is divided by 1e9 to get the values in GHz as the output equations returns values in base unit and for frequency it is Hz.
- Plot the BW_3dB output equation in a graph as shown below