ADF4350 - 500MHz Output Waveform

Hi. I am building a communication system and will be using ADF4350 as a local oscillator.
I need 500 MHz or 600 MHz constant output from both RF outputs.

What I've learnt from the related topics is that output waveform becomes more like a square wave rather than a sine wave if dividers are used.

I need to know how much the output waveform will look like a square wave if I use constant 500MHz or 600MHz output frequency.

Are there any references showing output waveform change with respect to output frequency ? 
Are there any suggestions for other IC's to use ?

Thanks in advance.