IP3 point of overall receiver

[viperpaki007]

Normally in receiver design, the later stages contribute to IP3 value more that the first stages but does anybody know the reason why it is like that.

regards

 

[kpc]

Hi,

In Pozar's Microwave Engineering 4th edition (page 516-517, section 10.3) formulation is presented. This formulation clearly shows the latter stages contribute much more than early stages. However, I don't know if there is simpler and more intuitive answer to your question. Maybe if you read that section, it may help you to understand better.

 

[shar2013]

Hi,

IP3 of a receiver is determined by the weakest link , i.e. the element with the lowest IP3.
IP3 is a small signal parameter , unlike IM3 which is a large signal parameter , where the gain in the receiver chain causes the
latest stage to be the strongest contributor