@User, after setting the bias point of the circuit with a .op simulation, a small signal .ac analysis can be done. You should connect a voltage source to the left pin of C1 with value="dc 0 ac 1 0". the '1 0' are the magnitude and phase of the AC signal. Since the circuit is linearized in the bias point it is common to use unit amplitude so the output gives you directly the transfer function. The statement for doing a frequency analysis is ".ac dec 10 1MEG 100G", meaning" do an AC analysis with 10 points per decade, from 100MHz up to 100GHz. The right end of C10 should be connected to a matched load, in many cases it is a 50 Ohm resistor. check the circuit paper or spec.