how to simulate quality factor of an spiral inductor in ADS?

Supposed that you have the inductor model...
It's easy: use a Term connected to the inductor and simulate as Spar in your frequency range (don't forget the gnd...)
Use Function: Yin=Port input admittance in Spar library.
Add the following MeasEqn to the schematic: Q=imag(Yin1)/real(Yin1).
You'll find the Q in the dataset to be plotted.

Bye
Mazz

You have a model for spiral inductor under lumped components pallete, and a choice of them in TLINE microstrip pallete. You can work with them in your circuit unless you wont to know exactly and in advance the Q of your inductor. They include loss calculation. You can calculate Q factor as stated above in previous mail. However, when you put your inductor between two ports, you are determining the loaded Q, it should be re-calculated to unloaded (inductor itself is loaded with 50 ohm port impedance, this is not true Q).

There is another method to determine unloaded Q directly - from short circuted inductor (one inductor terminal to ground, the other to 50 OHm port termination), and unloaded Q is determined from reflection.

flyhigh