Hi Leon, The formula for even and odd mode is a simple linear transform, where the two equations are: [M]*[L]*[M]^1 = transform to odd and even mode inductance [M]*[C]*[M]^1 = transform to odd and even mode capacitance This assumes that the capacitance matrix is in the proper form where: [Q] = [C]*[V], which is the Maxwell matrix. The trick is choosing the transformation matrix [M]. As with any linear transform, it must have the property: [M]*[M]^-1 = [I] For the typical 2-line case, [M] = (1/sqrt(2))*| 1 -1 | | 1 1 | Using the above transformation matrix, the odd mode becomes the upper left entry (11), and the even mode becomes the lower right entry (22). The off diagonal is then the mode conversion, which is non-zero if the coupled line matrix is asymmetric . This can be expanded to N number for entries. Hope this helps, Bill +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Bill Beale Phone: 503-439-3462 Sr. App. Engineer Fax: 503-466-9472 Accelerant Networks e-mail: bill_beale@xxxxxxxxxxxxxx On the world wide web @ http://www.accelerant.net +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx > [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Leon Wong > Sent: Monday, February 23, 2004 6:38 AM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Even and odd mode capacitances and > inductances of coupled lines > > > Hi, > > Does anyone know the formula for even and odd mode capacitances and > inductances of coupled lines? Is Lodd = L11-L12, Leven=L11+L12, > Codd=C11+|C12| and Ceven=C11-|C12|? Thanks in advance! > ------------------------------------------------------------------ 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: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.org List archives are viewable at: //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