AA

I am modelling an rf reciever, when modelling the noise I faced a proplem which is that when modelling mixer's noise an SST analysis should be used, But when modelling the LPF, which contains Laplace transform, there is some conflict between the SSt and the 'LTF, and the output is strange.
I wonder if there is a solution for this problem.

Yours
Shady Ragab