[help] Four fundermental questions in RF

Hi all,

here are two Qs:

Q1: what's the difference between 'Sensitivity' and 'Desired Signal Level'?

Q2: i saw both of them('Sensitivity' and 'Desired Signal Level') appear in the specs and sensitivity is used to calculate noise figure, while desired signal level is used to calculate phase noise, is it correct?; i am confused about IP3 calculation: which one is normally used? sensitivity or desired signal level?

Q3: in the calculation of phase noise, CIR (carrier to interference ratio) is used; can i replace it with SNR?

Q4: what is spurious suppression and how to calculate it?

Thanks!

c.m.