PA/LNA control signal problem


the waveform in the upside of the picture is the dw1000 GPIO5 control signa. the bottom waveform of the picture is the signal while that get through the 1k ohm resistance to the mmbt3904.
Why in the second pic half of the waveform
is distortion.

If I saw a trace like that the first thing I’d look at is the quality of the ground connection on the scope probe. 90% of the time traces like that are poor equipment setup rather than genuine issues.

If the green trace is being driven via a 1k resistor the next things I’d look for would be cross talk introducing noise after the resistor or power supply noise.