cadence pz analysis

Are you (jasonxian), pyroblast and ianx all on the same course? It's a bit suspicious there have been three questions about "Kp" in the last few weeks (and it's never come up before, so I smell a rat). Kp was a model parameter for old (very basic) MOS models representing the transconductance. There was some mention in other posts of "Kn" - but as far as I know the parameter was always Kp. In modern transistors, it is far more complex and so if you want the transconductance, I'd have thought you'd use "gm" from the operating point output. I don't know how you're determining the "Kp" of these devices - it's not a model parameter (unless you have a very strange 0.18 model deck).

As for your pz analysis, I have no idea whether there should be 5 poles and zeros. Note that the documentation for pz tells you about pole-zero cancellation. From the output of "spectre -h pz", I see:

Pole-zero cancellation is performed when a neighboring pole-zero pair is located within `absdiff' distance. The distance
is also determined relatively as `reldiff' times the magnitude of the pole or zero. Spectre uses the larger value of the
two distances for cancellation. A subtle note on resistance: by default, a lower bound of resistance is enforced; you
may remove this limitation by defining the resistor parameter `rac'. This may affect pz results.

pz analysis should be correct. But I don't know how you're using it...

Regards,

Andrew.