I have implemented a LNA using Sirenza's SBB-5089 MMIC on FR4 board. I have access to a network analyzer in the University lab containing HP 5071 network analyzer. I wnat to measure the LNAs noise figure using ONLY network analyzer. Is it possible?
I don't think so.
VNA is used to small signal response of circuits. It uses a sweeped CW signal and detectors to evaluate S parameters.
Noise figure is measured with a good accuracy with a noise source and Y-factor method, so you will need a receiver (typically a spectrum analizer or a dedicated instrument) to do it.
I hope it can help.
Mazz
If you have a good spectrum analyzer, you can "build" your own NF meter buying only the noise source and a low noise preamplifier.
As NF meter uses the Y factor method, based on high temp/low temp noise source, you can manually measure it (or implement a software in Labview, for example).
See agilent application notes for details, if interested.
Mazz
I have implemented a LNA using Sirenza's SBB-5089 MMIC on FR4 board. I have access to a network analyzer in the University lab containing HP 5071 network analyzer. I wnat to measure the LNAs noise figure using ONLY network analyzer. Is it possible?
but...if yuo have avaliable a noise generator
if your VNA may be switched in receiver mode
if your LNA has enough gain to mask the noise of VNA
the manual switching, noise measurement may be tryed, but this is a thinking speculation.
In any case, when measuring NF , the causes and sources of uncertainty are almost infinite.
My suggestion is if you have not a NFA and You cannot buy, the most cheaper way is to loan it for the period You plan to use.
you can measure the NF with a network.
1. connect the network for a S21 test.
2. connect the LNAs output to port 2.
3. meaure the noise level.
4. connect the LNA to DC.
5. measure the noise rise, it's G+NF, you know G so you can deduce NF.
6. if you don't see a noise rise it's becuse the network has a high NF, if that's the case connect a reference LNA between your DUT and the port.