Lowest noise does not equal highest gain.
Highest gain equals source impedance equals system impedance.
So, LNA equals source impedance gives not necessarely lowest noise.
Tune LNA for lowest noise, the gain will be somewhat lower.
Its the S/N ratio that counts especially important for an LNA.


"Joseph H Allen" schreef in bericht
...

What do you do if the input impedance of an LNA does not equal the source
impedance which gives the lowest noise?

The source might be an antenna, transmission line or filter which will not
work properly if it does not see the correct impedance.

--
/* AB1GO */ /* Joseph H.
Allen */
int
a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--q=3&(r=time(0)
+r*57)/7,q=q?q-1?q-2?1-p%79?-1:0%79-77?1:01659?79:0158?-79:0,q?!a[p+q*2
]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817printf(q%79?"%c":"%c\n","
#"[!a[q-1]]);}