What is the function of the DC Feed inductor in ADS?

what is the function of the DC Feed inductor what is the difference between it and other inductors
:D

Hi

It acts as a perfect short at DC and all other frequencies, it behave as an open circuit(∞ impedance at any AC signal).

Ordinary inductors has a finite L value, a DC feed inductor has an inductance value of L=∞.

Regards

DC feed inductors r normally used in circuits to decouple RF and DC portions in a circuit.

may be say it avoid ac and dc interference.

You need to protect the DC line from the RF signal, and lower frequency signal to be block from RF as it can give feedback from drain to gate and could cause oscillation.
You may also need to use capacitor after the inductor.