Problem on simulating Pnoise of mixer...

Hello everybody !
I am simulating a mixer now,
LO = 1.4G RF = 1.5G

I found something unexpected:
in Pnoise simultion , I swept from 1k to 2G,and chose
"reference bandside "as "0 -1 -2 ". and the result is
showed in figure a~c.

but I think the noise should be mixed and added together ,
and the result should be ...(figure d).

I don't know why . I have refered to Cadence's design guide
and the "designers-guide" website, but I can't find my answers

thank you for helping me !~~~ :)

Your "reference bandside" is wrong , it need to be set as "1", cause the LO is lower than RF.

In SpectreRF manual, it talks about setting 1 or -1 because it can be up/down conversion.

Oh, thank you

but after I set it to "1" , it seems that the noise moves to the "-1.5G", and the shape remain the same ! :(

Do you think my analysis is right in figure d?