IP2 measurement, single tone - RF Cafe Forums

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Y-11Bike

Post subject: IP2 measurement, single tone

Posted: Sat May 26, 2012 10:33 am

Lieutenant

Joined: Sat May 26, 2012 10:31 am
Posts: 1

Does anyone have a reliable technique to measure IP2 using a single input tone ?

I only have one signal generator available, and all the technical notes I've read seem overly cryptic.

Thanks,

Kirt Blattenberger

Post subject: Re: IP2 measurement, single tone

Posted: Sun May 27, 2012 11:13 am

Site Admin

Joined: Sun Aug 03, 2003 2:02 pm
Posts: 476
Location: Erie, PA

Greetings Y-11Bike:

Unfortunately, its full name, the 2-tone, 2nd-order intercept point, requires a second tone in order to do the measurement.

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SunshineDesign

Post subject: Re: IP2 measurement, single tone

Posted: Thu Aug 16, 2012 2:44 pm

Colonel

Joined: Sat Nov 08, 2008 11:35 pm
Posts: 30
Location: Ramona, CA

While there is no way to exactly measure IMD without at least 2 tones, there is a technique that gives some measrue of IMD performance and that is Noise Power Ratio. Take a white noise source and filter a narrow bandwidth with a very deep selectivity filter. When this signal goes thru the device under test, the backfill noise power into the notch is representative of Infinite tone IMD. White noise can be thought of as infinite frequency signals and the IMD of this noise is what spills over into the notch. For it to work, the notch filter must have reject selectivity greater than the IMD performance expected. While this is not a single tone generator, it is a single source (Noise Diode).

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Posted 11/12/2012