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Measuring the Noise Figure of a Lossy Active Device

Question asked by KeithV on Dec 22, 2010
Latest reply on Dec 22, 2010 by andyowen
I am trying to measure the noise figure of an active DUT that should have a gain of around -30 dB and a noise figure of 30-40 dB. 

I have trouble getting accurate results from the methods I have tried.  I have an E4440A and have tried using the Noise Figure measurement personality with a 346C Noise Source.  I have also tried the using a low noise figure amp after the DUT to boost the noise floor and calculated the noise figure using the noise floor of the combination and the gain of the low noise amp and DUT.  From what I have read I have too much loss and/or too much noise to get a good repeatable measurement.

I also have read about cold-source measurements but this seems daunting to do manually on potentially several hundred units a month. 

Anyone have suggestions on how I can get a good repeatable measurement without too much difficulty?  

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