Measure amplifier non-linearity using two-tone signal
- Take a USRP B200
- Connect its TX to the amplifier you want to measure
- Connect the amp to an big enough attenuator in order to reduce power to below 1mW
- Connect to the B200 RX
The amplitude ramp script is going to generate a two-tone (1kHz separation) signal at 222MHz, and record outgoing signal magnitude and phase difference against the source signal. The measurements are written into a CSV file.
It's your job to ensure you don't overload the B200 input signal power (-15dBm last time I checked).
Before you can start, use gnuradio-companion to generate dual_tone.py from dual_tone.grc
Then gather some measurements
./amplitude_ramp.py --ampl-start 0.15 --ampl-stop 0.5 --ampl-step 0.01 --num-meas 300 --txgain 77
This creates a measurement.csv file you can analyse with
That's it for now.