I am beginning to design a monolithic frequency synthesizer (around 2.4GHz) in which I need the maximum of spectral purity. I was looking at injection locked frequency dividers (ILFDs) for use as a prescaler as an alternative to flip-flop based prescalers. Are there disadvantages to using ILFDs in terms of spectral purity?
As a sub-question, there are two main types of ILFDs--LC based and ring oscillator based. Ring oscillators have a reputation of being jittery as opposed to LC oscillators. However, within the context of an ILFD, does this jittery-ness come into play? In other words, WRT spectral purity, would a ring-based ILFD be sub-par?