Post subject: Error in ADS Posted: Tue May 02, 2006 5:05 am
Joined: Tue May 02, 2006 4:59 am
I use the Budget tool and got that error message :
detected by HPEESOFSIM during Budget Analysis `Budget'.
During Budget cascaded noise analysis; possible element with
S-parameters; look for |S11| > .8; |S22| > .8; |S12| near, equal
or greater than |S21|. [/b]
Maybe anyone understand it ?
I know its depend on the attenuators location but im not understand
Post subject: ADS error messagePosted:
Tue May 02, 2006 6:32 pm
Joined: Wed Feb
22, 2006 3:51 pm
That's actually a more-helpful
error message than many, because it tells you what to look for in your
design. Unfortunately it's not very specific - it doesn't tell you where
to look, and it gives 3 alternatives.
The S11 and S22 checks
say that maybe there's a severe impedance mismatch between two stages,
the S12/S21 message says that maybe there's a large amount of (unexpected/undesired)
feedback around an active stage.
Post subject: Posted: Tue May 02, 2006 10:03 pm
Joined: Mon Jun 27, 2005 2:02 pm
I took the initiative and
replied to this post directly by email as we had already a brief correspondence
in the past. I mentioned that the main cause of such a problem is instability
(As fred47 mentioned), this is also noticed by the values of S11, S22
which are greater than 1. This is likely to be caused by poor matching.
I also suggest you to do the budget analysis simulation step by step
from the start: Block after block. And to see in which step the error
message displays. By doing that you can find out the problemtaic element
and check it separately.