The SFP+ power supply specification is the most convoluted standard I've seen so far. First, your power supply, preferably, should use a reference LC filter. Then you take a measurement at the output side the PSU. Finally you import the data to your computer and divide the results by the transfer function H(f) of that LC filter to deembed that filter and reconstruct the noise voltage before the reference filter.

WTF? (What The Filter?) #electronics