ads noise figure

Hi Guys
I am doing LNA noise figure simulation in ADS using sp simulator. Then I choose option to try to add noise in. but when I try to "select input port" to term 1, software reports *Warning* object selected is not a valid selection object. So I am wondering if I need to use some other ports to do it? I also tried to give the port number in "select input port" , then it works but I am not sure if it correct. Can anyone comfirm this by giving some offical link? Also, what is different between nf1 and nf2. It looks to me nf2 is a more reasonble nf.
Thanks a lot for your help.

don't specify any port , and plot the Nf(2), this is the input refereed noise figure when port 2 is the output

khouly

Yes, it seems to be the right way, but what's does the NF(1) refer to?
Thanks

as far as i know , it is the opposite of nf(2)

khouly

what does it mean? Opposite?

May be NF1 is noise figure at port 1(input port) & noise figure at port 2 i.e output posrt is NF2.
please confirm

I did not think so since NF1 is incredible high!

Alright, NF1 means the noise figure at port1 when port 2 is input. Similar to the meaning of NF2, the noise figure at port 2 when port 1 is input.

Game king is correct,
S12 will be low and hence you will get NF1 incredible high in LNA.