I want to know the inside netlist of the port present in analogLib ( the exact way it evaluates the signal ).
Can anybody please tell where I can gest this information from ?
It's just a voltage source which generates twice the level of signal that you specify, in series with a resistor (the value of which you specify, but defaults to 50Ohms). This is if you specify the signal level as a voltage rather than a power - and so if the circuit to which the port is connected is matched to the impedance, the voltage at the pin of the port should be what you specify.
Because there's a resistor inside, you can also specify the output as a power (in dBm). The resistor also serves as a noise source for measuring noise figure in the various noise analyses.
This is covered in "spectre -h port" (I think - I don't have access to the software right now) and also in the Virtuoso Simulator Components and Device Models Reference manual in the MMSIM documentation.
There's also the documentation for analogLib (in the IC documentation)