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Design >> RF Design >> IIP2 measurements
https://designers-guide.org/forum/YaBB.pl?num=1207676629

Message started by vivek1214 on Apr 8^th, 2008, 10:43am

Title: IIP2 measurements
Post by vivek1214 on Apr 8^th, 2008, 10:43am

hello,
I want to measure IIP2 of my system(BT receiver).center freq 2.44GHz

which tones I should take to measure IIP2?

Title: Re: IIP2 measurements
Post by Stefan on Apr 9^th, 2008, 12:17am

That strongly depends on the filter characteristics you chose for your system.
You need to use 2 frequencies that can travel through your input filters, across your LNA/Mixer stages and so on, until they reach (downconverted) the lowpass filters and the ADC.
The lowpass filters and bandwidth of your LNA/mixer combination specify the allowed distance between the two carriers, your simulation time requirements specify the minimum distance needed for effective simulation. However, when characterizing a wideband sytem, you should consider using 2.5GHz instead of 2.44GHz for easier use of fractional parameters ...

Title: Re: IIP2 measurements
Post by didac on Apr 9^th, 2008, 12:35pm

Hi,
If you are working with a direct conversion receiver I think that you should choose two tones which their difference results directly in the IF bandwidth(DC to 3dB corner of the IF filter) since they will leak through the mixer (finite RF-LO isolation), then you can compare the resulting IIP2 with the radio spec of adjacent channel level.
Hope it helps,

Title: Re: IIP2 measurements
Post by pancho_hideboo on Apr 10^th, 2008, 2:34am

See http://www.designers-guide.org/Forum/YaBB.pl?num=1193566207