I meet a problem while doing Pnoise analysis of mixer.

Hello all:

The example of mixer600p uses a port as a rf input port.
But in my design, i use a psin as the rf input.
During the anaylsis, i see that:

Port7 contains no noise, its NF and F are infinite.

What cause that problem and how to resolve this problem?

Thanks.

is port7 the input port?
it seems that you got no noise for the inout port..