Hello MarkS,
MarkS wrote on Nov 13th, 2014, 7:38am: Therefore, the higher the phase detector frequency, the lower the phase noise overall.
I don't think this conclusion is valid in general.
Assume PLL output frequency to be fixed, the conclusion is kind of true.
Yet, if you assume the division factor of a PLL to be fixed, which maybe more practical to keep the same loop dynamics of PLL, the phase noise of PLL actually increases with fpd, since the quadratic term of fo in the numerators in EQ1.
In case you're interested, the following paper did detailed analysis of PFD noise contribution, and the conclusion they reach agrees with the latter case.
Homayoun, A.; Razavi, B., "Analysis of Phase Noise in Phase/Frequency Detectors," Circuits and Systems I: Regular Papers, IEEE Transactions on , vol.60, no.3, pp.529,539, March 2013.