keio-rfic, don't do duplicate posts.
The following two are completely same.
http://www.designers-guide.org/Forum/YaBB.pl?num=1244700012/2#2 http://www.designers-guide.org/Forum/YaBB.pl?num=1244700012/3#3waseda-rfic wrote on Jun 11th, 2009, 7:19pm:active cascode and cascode bootstrap can increase the output impedence in low frequency.
but i am not sure it is also effective in RF frequency as in 5 GHz?
It is effective. But it is not effective for capacitive component of output impedence.
waseda-rfic wrote on Jun 11th, 2009, 7:19pm:i see in the paper. they mainly use offset line or match network to increase the impedence.
but in my simulation, i find hard to satisfy both load line and high output impedence using match network.
so i want ask which is better for improve the impedence?
Both cascode amplifier and reactive impedance transformer using discrete LC or distributed lines are needed.