## [SI-LIST] Re: Even mode, common mode, and mode conversion

• From: "Fred Balistreri" <fred@xxxxxxxxxxxxx>
• To: <doug@xxxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
• Date: Wed, 27 Feb 2002 10:51:41 -0800

```There have been excellent responses on this subject. Perhaps one may better
understand the
meaning of odd, even modes by looking at the equations from where they
originate:
Given that there are 2 lines wrt gnd or some plane or in the microwave
description 3 lines, with
one being a reference and given the Maxwell's LC matrix then:

Odd = sqrt  L11-L12/C11+|C12|
Even = sqrt  L11+L12/C11-|C12|

Note that the loop inductance is minimized and capacitance maximized for odd
mode. The opposite is
true for the even mode. Thus the differences in impedance. The coupling is
the key.
Note that in Maxwell's C matrix the mutual capacitance is desginated as
negative, therefore the absolute brackets.

Best Regards,

----- Original Message -----
From: "Doug Brooks" <doug@xxxxxxxxxx>
To: <si-list@xxxxxxxxxxxxx>
Sent: Monday, February 25, 2002 9:31 AM
Subject: [SI-LIST] Even mode, common mode, and mode conversion

>
> Gurus,
>
> I've been following the thread on mode conversion and suspect I am not the
> only one with this question. Can someone explain, in layman's terms:
>
> The distinction between even mode and common mode?
>         between odd mode and differential MODE (not to be confused with
> differential traces)
>
> And does the existence of differential traces add any complications to
> these distinctions?
>
> Thanks for bringing the dummies along with you!
>
> Doug Brooks
>
>
> ------------------------------------------------------------------
> 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
>
>

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

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

```