Thanks a lot for the quick replies. Well, the design of the circuit assures that we have current gain of 30. I think, this is solved by the choice of resistors. Also, we dont care about voltage gain. Considering now the range of frequencies, its up to me,so as a typical value I determine the fL( f-3db), lets say 1KHz. In previous labs with bjts, and in other assignments of this lab (common source amplifier), i found the values of the capacitors succesfully, using rules such as C=1/2*π*fL*R, but in this circuit, this calculations dont give me the frequency I am expecting.