chenyan, thanks for comments.
rfmems wrote on Apr 24th, 2009, 6:35am:Your floating PGS is a good point.
In this case I guess the parasitic cap from inductor to floating shield in series with the cap between shield to substrate, am I right?
Right.
rfmems wrote on Apr 24th, 2009, 6:35am:With this method, I suppose you can reduce the Cp from ind to ground, but to which extent?
If top two metals are enough far from substrate, there is almost no reduction of Cp even if I use floating PGS.
But they are not so far from substrate in my cheap process.
rfmems wrote on Apr 24th, 2009, 6:35am:Acoording to my simulation, 1-2GHz is fine,
but higher you see the internal inductance start to fall below the same geomtry without PGS.
What do you mean by "
the internal inductance" ?
http://www.designers-guide.org/Forum/YaBB.pl?num=1205240723/1#1rfmems wrote on Apr 24th, 2009, 6:35am:So maybe your inductor works in the range of 1-2GHz or its proximity. Let me know if I was wrong.
Operation frequency of my application is 2.4GHz.