Hello,
I am trying to determine the center frequency of an LC tank for an NMOS LC VCO. I followed this note from a previous question. https://community.cadence.com/cadence_technology_forums/f/rf-design/32224/lc-parallel-circuit-at-resonant-frequency
I did run an s-parameter simulation of the impedance against the frequency on the ideal LC tank and s11 produces the expected response. I am attaching the circuit and the response. On the other hand, when I use real devices, it is producing something different. I consulted the model file for the 130nm hp process but I am not getting it to produce the desired response. I am attaching the schematic and the waveform I am getting.
What am I doing wrong?
Thank you so much in advance.
