system IIP2 (second order intermodulation distortion)

[eng-a-hesham]

in the phase of receiver's system design (system specifications extraction) i've evaluated the wanted IIP3 as

IIP3=(3Pin-Pim3)/2

Pim3=10log(K.T.B)+NF (B -> bandwidth)

but now i cant find a method to get IIP2 ??! any ideas !!! :?:

 

[David.D]

Reference:
<Accurate and Rapid Measurement of IP2 and IP3> https://www.designers-guide.org/analysis/intercept-point.pdf

 

[eng-a-hesham]

i think this method can be done only after having a system model because the equation variables values can only be obtained from simulation ( measurements phase) .. but now i'm obtaining the system specifications from the standard and this method will not work with me .. !!

 

[RFDave]

So the 2nd order products typically show up at baseband (f1-f2) or at the 2nd harmonic. You need to look at the system requirements. For a superset receiver, generally 2nd iip doesn't cause a problem because bothe of these are filtered out. For a direct conversion receiver design, you need to look at dc offset requirements for the arc.

Dave