AnsweredAssumed Answered

NF with blocker

Question asked by kh4n on Nov 24, 2012
Latest reply on Nov 29, 2012 by kh4n

Hi,

 

At the datasheet of ADL5382 there is a section that describes noise figure measurement performance, under the effect of a blocker signal.

And there is a plot showing NF vs blocker power.

What is the method used for NF measurement, is it Y-factor without noise source?

My question is not specifically about ADL5382 but any demodulator or down-converting mixer, or LNA, etc.

I mean, at the setup diagram there is no noise source, only blocker signal is injected to the RF input.

How can I measure NF performance with blocker + noise source. I tried connecting noise source to RF input and injected blocker signal with a directional coupler, but NF seems to degrade a lot.

Is my approach correct, any suggestions would be appreciated.

 

nf.png

thanks in advance...

Outcomes