I want to design a PLL for multiplying the frequency of the reference input about 10MHz sine to 1GHz sine(or 1MHz sine to 100MHz sine),in this process.PFD(phase frequency detector) is a key component in low phase noise frequency multiplication appliations. there are two PFDs that have good phase noise performance from comparation in many frequency detector and PLLs.but I don't know how to compare this two PFDs.So which one has a better phase noise performance? and if the phase noise of the 10MHz and 1MHz input reference signals are equal. which one as for the input reference will produce the least phase noise(1MHz-100MHz or 10MHz-1GHz)? Thank you.