unevb wrote on May 5th, 2010, 10:46am:Not many IEEE Papers on LNA circuits talk about the k-factor of the circuit.
K-factor is not used except for LNA generally.
K-factor is not used for PA design where large signal is concerned.
I don't use K-factor even for LNA.
See the followings.
http://www.designers-guide.org/Forum/YaBB.pl?num=1218635777/5#5http://www.designers-guide.org/Forum/YaBB.pl?num=1266403928/4#4unevb wrote on May 5th, 2010, 10:46am:Why is k-factor an issue at RF but not an issue at low frequency (audio-range) circuits?
Consider loads for RF and audio.
Former is a resonator in many cases where impedance change drastically with frequency.
Latter is a resistor in many cases where impedance almost does not change with frequency.
pancho_hideboo wrote on Apr 29th, 2010, 8:54am:unevb wrote on May 5th, 2010, 10:46am:I have not seen integrated circuits using input shunt resistors because of noise considerations.
It seems you only know "EDA Tool Play" and technical paper.
We make bias circuitry and feed back network having frequency characteristics to prevent unpreferable oscillation in actual circuits.
Shunt resistor which is effective for some frequency range is also this purpose.
Cascode structure could be candidate for some case.
BTW, have you been able to understand the following ?
http://www.designers-guide.org/Forum/YaBB.pl?num=1272508752/3#3MAG, MSG and U are not dependent on reference impedance even if S-parameter expressions are used.