Dear Sirs, I drawed a structure with 6 capacitors (see file MultiCap.png in attach, please).
After simulation (@ 10 Mhz, 500 Mhz and 1 Ghz), I select N-port PI Network with shunt RC in Lumped Model.
I notice that some capacitance values (even if they are very small) are negative.
What that means?
Thanks a lot for your support.