Post subject: coupled microstrip lines
Mon May 24, 2004 2:09 pm
May 24, 2004 1:56 pm
Location: Moorestown, NJ
anyone have any tricks for optimizing coupled microstrip lines for differential
mode (Zodd=50ohms, Zeven=100ohms)? I find that the closed form models
in ADS and AWR do not match what is produced in Sonnet or Momentum.
Thanks for any help,
Unread postPosted: Tue May 25, 2004
Sonnet and Momentum are "2.5D" simulators, the conductors
must be zero thickness. Are you accounting for this? Momentum lets you
define conductor thickness only for signal attenuation calculations
not for geometric impact on electrical performance. Finite conductor
thickness will have an effect on the odd mode impedance.
understanding, the "closed form" solver in LineCalc of ADS is a curve
match to emperical and 3D simulated data for coupled lines. I have found
it to be accurate enough for most edge coupled filters, as well as much
faster than a MOM solver.
Unread postPosted: Tue Jun 01, 2004 2:47 am
The differential issue does not work properly in AWR. Sonnet
seems to be closer. anyway, measure and compare it.
I came to 98%
agreement with hand-calculation on 200ohm diff TL. The vector analyzer
measure single ended parameters, then it converts to diff. Do you want
the formula for conversion?