Hello!I want to determine the phase and frequency response of a buffer amplifier using the AGW PXI-5441 and PXI-5922 digitizer with very high accuracy. I've tried with white noise and the frequency response step in signal express but the accuracy is not that good. The phase and amplitude error is to big with out any amplifier (just two cables connected directly from the 5441 to the 5922), I want a totally flat response when the amplifier isn’t connected. I guess that it is possible to calibrate away this error in some way but I don't know how to.However, a frequency sweep should give better accuracy. I've found some different examples on this but none of them use any PXI units and haven’t been able to make it work on my own. In signal express I use the NI-FGEN, NI-SCOPE and amplitude and levels step in a sweep-loop but the result is nothing close to a flat spectrum. I assume this is due to that the samples on the sine wave are taken on different places on the wave, nothing weird with this just not what I wanted. The frequency response step does not seem to work in a sweep loop?Maybe I must consider a Labview solution, I have the spectral measurement toolkit installed.
