transistor bias inorder to have unilateral response

i want to design a bias network for a transistor inorder to have unilateral response .any one know how i can design it?

What do you mean by "unilateral response"?

s21 near one and s12 near 0 . it is one of the well known transistor situation like off or saturation

You have to design a feedback network that "eliminates" the, let me say, internal feedback of the device that allows the signal to go from output to input. So isn't matter of bias but feedback. This task can be more or less complicated depending on the S12 performance you want to achive as well as the bandwitdh you have to operate in. Probabily googling "amplifier unilateralization" or "amplifier neutralization" you can find some pratical example. Here is an old but useful application note from Motorola: http://een.iust.ac.ir/profs/Tayarani/files/AN215A.pdf

Do you know : is it possible to define special kind of transistor (transfer s2p file of special kind of transistor) in cst simulation?

if it is possible take a look at attached file i want to manufacture this structure but i dont have this transistor and i should change the transistor then i dont know what can i do fo dc biase and matching network , it doesnt have feedback as you said , any idea?
i think i should use ads but i dont know how ! i use atf36077 transistor.