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LNA's output power saturation and analysis

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Micro12

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Hi

I have low noise amplifier with gain = 22.5 dB (ZX60-P162LN+, https://www.minicircuits.com/pdfs/ZX60-P162LN+.pdf). His OUTPUT POWER AT 1-dB COMPRESSION = 20 dBm. I would like to know if I have 25 dBm at the input of the LNA, which power would I get at the LNA's output? (20 dBm, 47.5 dBm or something else) Also, I would like to know if the LNA's output power would saturate before reaching 47.5 dBm according to this datasheet when input = 25 dBm?

thank you
 

If you apply +25dBm to that amplifier the output will not be increased much because gain will start to decrease beyond P1dB point.
The definition P1dB, the output power reaches a certain point where the small signal gain drops by 1dB.Or linear relationship between Input Power vs. Output Power drops by 1dB
They are same thing.
 
BigBoss said:
If you apply +25dBm to that amplifier the output will not be increased much because gain will start to decrease beyond P1dB point.
The definition P1dB, the output power reaches a certain point where the small signal gain drops by 1dB.Or linear relationship between Input Power vs. Output Power drops by 1dB
They are same thing.
Click to expand...

From the datasheet, the P1dB point at 1GHz is 19.9 dBm.
1)Does that mean that the LNA's maximum possible output power is 19.9 dBm?
2)and if the LNA's input is 30 dBm, his output power would be smaller than for the case his input = 20 dBm for exemple because of the decrease beyond the P1dB point ?

thank you
 

Micro12 said:
From the datasheet, the P1dB point at 1GHz is 19.9 dBm.
1)Does that mean that the LNA's maximum possible output power is 19.9 dBm?
Click to expand...
No, but pushing beyond that would mean operating the amplifier in a very nonlinear way, and the actual output power you get would be difficult to predict. Such operation is generally undesirable, so manufacturers typically don't bother specifying it.
2)and if the LNA's input is 30 dBm, his output power would be smaller than for the case his input = 20 dBm for exemple because of the decrease beyond the P1dB point ?
Click to expand...
At Pin=30dBm, the amplifier would likely be damaged. See the maximum ratings, max Pin is given as 25dBm.
 
Micro12 said:
From the datasheet, the P1dB point at 1GHz is 19.9 dBm.
1)Does that mean that the LNA's maximum possible output power is 19.9 dBm?
2)and if the LNA's input is 30 dBm, his output power would be smaller than for the case his input = 20 dBm for exemple because of the decrease beyond the P1dB point ?

thank you
Click to expand...

1-Output Power can be "a bit higher" than P1dB with expense of linearity ( harmonic levels will be higher)
2-If you drive this amplifier with +30dBm input signal, you'll get a evidently an melded amplifier..-)
 
BigBoss said:
1-Output Power can be "a bit higher" than P1dB with expense of linearity ( harmonic levels will be higher)
2-If you drive this amplifier with +30dBm input signal, you'll get a evidently an melded amplifier..-)
Click to expand...

If the LNA's input is 25 dBm ( max Pin = 25 dBm), his output power would be smaller than for the case his input = 15 dBm for exemple because of the decrease beyond the P1dB point ?
 

Micro12 said:
If the LNA's input is 25 dBm ( max Pin = 25 dBm), his output power would be smaller than for the case his input = 15 dBm for exemple because of the decrease beyond the P1dB point ?
Click to expand...

in order to say that, the Pout vs. Pin characteristics should be known well.
 

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