IIP3 vs OIP3 quick questions

[ghb]

lease just for clarification.

Third order intercept describes the power level at which the third order harmonic gain would intercept that of the desired gain?

IIP3 describes how much power seen or received by the LNA at which this point intercepts? And OIP3 is what exactly? dBm out of the LNA with the given IIP3 power?

Say for example we have a 30 dB LNA. And the IIP3 is -10dBm would we expect the OIP3 to be +20dBm or would it be something different because of this high input power?

thanks so much for the help

 

[pstuckey]

OIP3 = IIP3 + G

Typically manufacturers quote whichever is higher, and they often just call it IP3 and assume the user knows whether it refers to input or output. For devices with positive gain (amplifiers) OIP3 will be higher and is typically what manufacturers spec. For devices with loss (passive mixers) IIP3 will be higher.

Peter

 

[ghb]

thanks