How to Measure Tank Impedance of LC Tank in Cross Coupled CMOS Oscillator

Hello,

I am designing a CMOS LC Cross Coupled Oscillator in ADS.

How do I measure the Tank Impedance in ADS - What testbench and set up would I use - would I just measure the Input Impedance using Zin.

I also want to measure the Q of the tank as well to compare both to my hand calculations and justify why I picked the sizing of the transistors and the varactors that I did.

OR How do I simulate this in another software.

Thanks!

The LC tank has two types of impedance:

* ohmic resistance or DC resistance (which is in the inductor). You can read it with a multimeter. The greater this is, the less is its Q.

* AC impedance, which depends on frequency. At the resonant frequency it can be close to zero. When it is operating in an oscillator circuit, you can measure impedance indirectly, by reading AC voltage across the inductor and capacitor. Divide it by current (read as voltage across a low-ohm resistor).