# LNA measurements using only network analyzer

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#### carbon9

##### Member level 3
lna measurements

Hello,

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?

Thanks

#### Mazz

noise figure measurement using network analyzer

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

### carbon9

points: 2

#### khouly

network lna

some VANs of anrtisu have noise figure measuetns ,

but if u want to measure the NF use NF meter of agilent
so ur VNA is not enough

khouly

### carbon9

points: 2

#### 7rots51

measuring lna application note

what is the price of NF meter( from several vendors)?

#### 7rots51

spf-5043z

SBB-5089 MMIC have high NF ,it is not good for LNA.Use SPF-5043Z with NF=0.8dB and freq=100-4000MhZ,in/out 50 ohm matched!

It is 28K$! Is there any low cost NF Meter (about 5K$)?

#### khouly

lna measure

5 K Noise figure meter , i doubt it

u can search for used items , but new one , it will be hard

khouly

#### carbon9

##### Member level 3
lna vna

Thanks for all replies.

I will now search for a cheap NF meter.

Thanks

#### Mazz

lna measurement

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

#### sergio mariotti

measurements with a network analyzer

carbon9 said:
Hello,

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?

Thanks
The answer is NO, IT'S NOT POSSIBLE.

but...if yuo have avaliable a noise generator
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.

#### DeeLau

##### Newbie level 4
pna-x using as spectrum analyzer

of course u can do it, with the newest high performance Agilent VNANA-X,

u can finish all the LNA measurements including the NF, IMD, harmonics,Gain

compression.

pls check www.agilent.com/find/pnax

#### molidong

##### Junior Member level 1
lna measurements using network analyzer

Spectrum analyzer can measure LNA noise figure!

#### SagSag

##### Full Member level 1
measure lna design with network analyzer

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.

you should also use a low RBW.

enjoy

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