For getting differential L and Q I can
1) either use one differential port
2) or use 2 single-ended ports and then get the mixed-mode S parameters.
Both above-mentioned methods of 1 and 2 for differential L and Q give same results.
However for getting single-ended L and Q I use single-mode S parameters.
There is a slight discrepancy in L and Q of the inductor if I simulate it with differential port or single-ended ports.
My question: is this common and normal?
I understand that those shunt R and C networks at port1 and port2 are for pads.
Why is that in your schematic, the inductor model has another L at port1 in addition to well known combination of R and L in series with shunt capacitor.
Could you be more elaborate with some equations.
And what does this different L and Q imply? With different signaling we'll achieve different L and Q?
Therefore, since transformers are mostly used in differential structures, we should use differential L and Q. (correct me if I am wrong)
What if they are used only for impedance transformation?
What I recommend to my Sonnet customers is to simulate as a two-port, so that both common and differential mode are included in the data, and then use that two-port in Cadence. This is the safest method, in my opinion. Doing only the differential case might by too optimistic if the actual circuit has some common mode component.
I am simulating with Momentum. Since I am using patterned ground shield, I can not use ///GND/// of Momentum.
Also using ground reference ports has its own problems. Therefore I am using differential ports and I will miss common-mode data.
If you have experience in simulating an inductor (with patterned ground shield) as a two-port inductor using Momentum, please advise.