How to compare the PIM Level from different test freq? - RF Cafe Forums

 Post subject: How to compare the PIM Level from different test freq?

Posted: Tue Jan 29, 2008 5:33 pm 

I got a question about PIM test result.
PIM test is done by using two tones test. However, the frequency of the two tones are not standardized.
Let's say we have two sets of test results from two different companies and they are using different frequency setting (one for 869 MHz & 891 MHz, the other for 1100MHz & 1900 MHz). Their results have the same PIM level.

Which one will be better? and Why?

* I am assuming the one with higher freq tones will be better, because of the skin-effect, but I have a hard time to find any document to approve the relationship between testing frequency, skin-effect, and PIM level.

 Post subject:

Posted: Tue May 20, 2008 4:57 pm 

Hi,

PIM means passive intermodulation, and it refers to in-band spurious tones, so you should perform the test with the tones on the frequencies on which your device normally works... if your device works form 800 to 900MHz, you should perform the test with the one with the tones inn 869 MHz & 891 MHz...
In the case that your device works from, let´s say: 600 to 2000MHz, then both measurements are ok, none of them is more characteristic than the other one, and if you need to give a product specification... provide both, explaining each test conditions.

Hope to be helpful
Bye

 Post subject:

Posted: Tue May 20, 2008 5:13 pm 

Thanks, FSomma