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Simulators >> RF Simulators >> Rapid IP3 simulation
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Message started by hamed on Oct 12^th, 2007, 2:34am

Title: Rapid IP3 simulation
Post by hamed on Oct 12^th, 2007, 2:34am

Hi
I have two similar LNA (in terms of architecture), one working in VHF and the other in UHF band.
Applying the Rapid IP3 Simulation with PAC and PSS Analyses (as mentioned in a paper from Ken Kundert), I have correct and reasonable results for the UHF LNA tuned in its typical channel. Doing the same for VHF LNA I see something strange; the IP3 is lower than CP!! by around 11dBm. Could somebody please help me on this?

Hamed

Title: Re: Rapid IP3 simulation
Post by pancho_hideboo on Oct 12^th, 2007, 2:57am

Hi.

If nonlinearity is dominated by input characteristics, IIP3 will be larger than P1dBin by about 10dB.
But if nonlinearity is dominated by output, for example, output is saturated by low power supply voltage,
IIP3 could be lesser than P1dBin.

Check whether output node is at near saturated operation point.