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Measurement of LNA general parameters measured

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robismyname

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Is there a book/white paper that discusses LNA measurements (2.4 GHz applications)? In particular.......

1) Measure LNA gain
2) Measure LNA input impedance
3) Measure LNA output impedance
4) Measure LNA noise figure
5) Measure LNA linearity
6) Measure LNA P1dB
7) Measure LNA BW
8) Measure LNA unconditional stability

Need some resources (books, whitepapers/application notes, URL's) on how to do the above measurements properly.
 

Hi

I don't know what simulation software you are using, if you are using cadence then in cadence documentation you will get all the details of how to simulate an LNA in cadence.
 

im not trying to simulate a lna. i am trying to measure the parameters of a lna physically........
 

Have you a VNA (Vector Network Analyzer)? Do you know how to use one? Most of the measurements you need can be done with one.
 

1) Measure LNA gain
2) Measure LNA input impedance
3) Measure LNA output impedance
4) Measure LNA noise figure (*)
5) Measure LNA linearity
6) Measure LNA P1dB
7) Measure LNA BW
8) Measure LNA unconditional stability (*)

It will do almost all of your measurements, except those marked with (*).
 

4) the NF can be measure by noi figure meter, some SA also have such function.
8) there is simple method: no input, watch the output. Or 50 ohms terminate the input, watch the output.
You shoud also measure the ambient temperature variation.
 

tony_lth said:
4) the NF can be measure by noi figure meter, some SA also have such function.
Click to expand...

My SA availability is: HP / Agilent E4404B. It does not support noise figure measurement. So LNA NF measurement can be done with my Spectrum Analyzer and a Noise Source?

---------- Post added at 23:05 ---------- Previous post was at 23:03 ----------
tony_lth said:
4) the NF can be measure by noi figure meter, some SA also have such function.
Click to expand...

My SA availability is: HP / Agilent E4404B. It does not support noise figure measurement. So LNA NF measurement can be done with my Spectrum Analyzer and a Noise Source?
 

yes, it's possible.
 

Attachments

  • 5952 NF measurement accuracy Y-factor method.pdf
    1.1 MB · Views: 141

robismyname said:
Dumb question but are there any special details or conditions related to powering the LNA or not powering the LNA when all these test are being done?
Click to expand...

Of course your LNA must be powered, why would you characterize a "dead" LNA?
 

robismyname said:
Dumb question but are there any special details or conditions related to powering the LNA or not powering the LNA when all these test are being done?
Click to expand...

How do you bias your LNA? Bias Tees? Have you DC blocks between your LNA and your test equipment?
 

Im looking at the reference diagram of the RF2472G. It has a 22nf on RF in. Is that a coupling cap? RF out (pin 5) has a more elaborate circuit perhaps a band pass filter? and is 22nf a coupling cap as as well?

 

Yes, both cap are DC block cap.
The circuit maybe is output match ciruit, and act as LPF
 

etmabreu said:
1)

7) Measure LNA BW

It will do almost all of your measurements, except those marked with (*).
Click to expand...

Just how would you go by measuring the BW of a LNA with a VNA? Is the BW of the LNA measured with S21 in log mag setting or should I use the smith chart? My start freq should be 50MHz and my Stop frequency should be 20GHz?
 

robismyname said:
Just how would you go by measuring the BW of a LNA with a VNA? Is the BW of the LNA measured with S21 in log mag setting or should I use the smith chart? My start freq should be 50MHz and my Stop frequency should be 20GHz?
Click to expand...

S21, log magnitude. Usually stop and start are taken as the frequencies where the gain falls 3dB from the passband.
 

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