FreeLists / si-list / [SI-LIST] Re: GND is perfect conductor?

["D G" <dgun@xxxxxxxxxx>]

Jeff,

Assuming you are using ADS Momentum, you can just create/modify the substrate 
from the Momentum pull-down menu.  From there you can assign conductivity and 
thickness properties to the ground layer or any signal layer.  It should 
calculate loss appropriately.

--
Daniel


----- Original Message -----
From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
> We routinely assume perfect conductors for ground in our field solvers.
> In fact, I don't believe you have an option of doing otherwise for ADS
> (I've got a request in for information on this, but can't get a reply
> until next week).  And, for XFX, I don't know whether it comprehends any
> skin effects of the Ground plane (it  says it applies the default rho
> for resistivity, but I don't know what that does for an infinitely wide
> conductor).  Ansoft  Q2D, on the other hand, allows setting the
> characteristics of the ground plane (since it's just another conductor).
> 
> I would expect that, at  current (>5GHz) frequencies, the ground plane
> losses would have a significant effect (the current in the ground plane
> would be a mirror image of that in the signal conductor), including skin
> effects.   The Hall, Hall, McCall book even gives a formula for the
> effect (page 80).  But, our simulators don't seem to take it into
> account.
> 
> 1) Does anyone have any information (data would be preferred, vs.
> conjecture) on the effects of using a perfect vs. imperfect conductor
> for ground?
> 
> 2) If ground plane losses don't have any effect, why don't they?
> 
> 3) If ground plane losses do have an effect, how do you properly model
> them in XFX and/or ADS?
> 
> Jeff Loyer=20

-- 
__________________________________________________________
Sign-up for your own personalized E-mail at Mail.com
http://www.mail.com/?sr=signup

CareerBuilder.com has over 400,000 jobs. Be smarter about your job search
http://corp.mail.com/careers

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu