CG(common gate)-UWB LNA

[oabedi]

Would you:

-By theory input matching of CG-LNA should be 1/gm. Do CG-LNA require network matching, if yes, please send some papers or topology.

-I did input matching by shunt capacitor and serios resistor but gain is very low and NF is realy high which is far from CG-LNA subject.
enclosed you'll find my design.

if you have any idea or topology(Wideband), please let me know.

 

[milkdragon]

Not sure what frequency you are working on. For low frequency, you do not need matching network, except the DC blocking capacitor. What you need is to adjust 1/gm close to 50Ohm, and a choke to ground. You may also make use of the choke inductance to cancel out the parasitic capacitance of the device for better match at high frequency.

More trade-off can be done for NF by making Gm larger

The other way to get broadband matching is to use Ladder type matching or distributed amplifier, they both are mainly for high frequency design

 

[fanshuo]

why is your input gm=40ms?
Should not it be 20ms?
and what is that C17 for?You may short your signal to ground by using that capacitor