aaron_do wrote on Aug 1st, 2011, 6:27pm:For your point about having a well-defined field configuration, are you basically saying that the ground ring helps to define boundaries for the field?
Yes, and the same applies for the patterned ground shield.
aaron_do wrote on Aug 1st, 2011, 6:27pm:Just from a academic point of view, I'm wondering does the ring directly add to the measured inductance (see the attachment)? From my understanding, this return path inductance must be de-embedded from the measurement by using open, short, and thru test structures with the same return path.
With permission from Dr. Volker Mühlhaus (
http://www.muehlhaus.com/), I have attached the relevant pages from a presentation he gave us a year ago. On page 10, you can see the effect of the ring on the inductance. According to Dr. Mühlhaus, this effect cannot easily be removed by deembedding (see page 9).