RF Cascade Workbook for Excel
RF & Electronics Symbols for Visio
RF & Electronics Symbols for Office
RF & Electronics Stencils for Visio
RF Workbench
T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads
Espresso Engineering Workbook™
Smith Chart™ for Excel
|
 |
Noise figure measurements - RF Cafe Forums
|
Seth
Post subject: Noise figure measurements Posted: Thu Mar 19,
2009 2:56 am
Lieutenant
Joined: Sun Nov 02, 2008 10:16
pm
Posts: 1
My question is on sub 1 dB noise figure measurements.
Although I am using a low ENR source and an industry standard noise
figure analyzer, I get the impression that the noise figure readings
are consistently a little on the high side (0.2-0.3 dB higher) on the
low noise amplifiers that I am measuring. Is there an accurate way to
cross check the measurements that I am making? The instrument noise
figure at the frequency of measurement is about 8.5 dB. Does one have
to use a preamplifier to get more accurate results?
Top
nubbage
Post subject: Re: Noise figure measurementsPosted:
Sat Mar 21, 2009 6:32 am
General
Joined: Fri Feb
17, 2006 12:07 pm
Posts: 218
Location: London UK
Hi Seth
I had a look at graph 6.1 of Agilent's App Note 57-2 "Noise Figure Measurement
Accuracy". It estimates around 0.3dB error when using an analyzer with
an 8.5dB NF.
You might expect an error of around 0.2dB if you place
a good 2dB NF pre-amp in front of the analyzer.
_________________
At bottom, life is all about
Sucking in and blowing out.
Top
IR
Post subject: Re: Noise figure measurementsPosted:
Sat Mar 21, 2009 3:55 pm
Site Admin
Joined: Mon Jun
27, 2005 2:02 pm
Posts: 373
Location: Germany
You can do the
following:
1. Compare the measurements between different DUT's
and get a insight on the error magnitude.
2. Use another unit of
the same Noise Figure Analyzer which you currently use and see if you
get the same size of error - then most probably it is a measurement
error of the Analyzer.
3. Better not to use another preamplifier,
because then you add another error factors to your measurement setup
(Gain and NF).
_________________
Best regards,
- IR
Posted 11/12/2012
|
|
|
 |
