no noise figure analyzer how to measure a new LNA NF? - RF Cafe Forums

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LELE FIR
 Post subject: no noise figure analyzer how to measure a new LNA NF?
Posted: Tue Aug 21, 2007 10:19 am 
 
Lieutenant

Joined: Tue Aug 21, 2007 9:43 am
Posts: 3
Location: shanghai
I have design a ATF-54143 LNA
but have no noise figure analyzer
just a HP8563E Spectrum and a signal generator and vector analyzer
so I can measure S21 and S12 S11 and P1dB

BUT I can not measure NF of LNA .
Spectrum have so more error when connect with generator.

HOW can I measure a NF of LNA without noise figure analyzer

thank you .
 
   
 
RFDave
 Post subject:
Posted: Tue Aug 21, 2007 9:50 pm 
 
Captain
User avatar

Joined: Sat Apr 22, 2006 11:14 pm
Posts: 20
You need a calibrated noise source to do a Y-Factor measurement. Agilent has a good app note at http://cp.literature.agilent.com/litweb ... -3706E.pdf

App Note 57-1 is also a good reference.

Dave
 
   
 
LELE FIR
 Post subject:
Posted: Wed Aug 22, 2007 8:37 am 
 
Lieutenant

Joined: Tue Aug 21, 2007 9:43 am
Posts: 3
Location: shanghai
THANK you

I known these 3 ways to measue NF .

1 use noise figure analyzer ,(I have not)

2 use spectrum to calculate NF.GAIN measurement ( our company's spectrum have so many errors)

3 use Y-Factor measurement (I have not noise source).

oh, no way
 
   
 
RFDave
 Post subject:
Posted: Thu Aug 23, 2007 9:54 pm 
 
Captain
User avatar

Joined: Sat Apr 22, 2006 11:14 pm
Posts: 20
The Noise figure meter simply automates the Y-factor measurement. You really need a noise source to do this. It's been a long time since I purchased a noise source, but google is your friend here. The Amateur radio community has build up noise sources from Noise diodes and Zener diodes, so you could probably DIY a noise source if you have to.

Dave
www.keystoneradio.com




Posted  11/12/2012