Jongbae, Even in an homogeneous coupled stripline structure, the wave speed is not the same for even and odd propagation modes, hence the difference between common and diff. mode prop. delays. For cases where mutual coupling is very small they get close but theoretically there'll be a difference. The same reasoning applies to the coupled microstrip lines. Regards Ihsan On 3/9/07, jbtera77@xxxxxxxxx <jbtera77@xxxxxxxxx> wrote: > Hi, all > As all know, in homogeneous strip line, the propagation speed is the same > for both differential and common mode. > > However, in inhomogeneous microstrip line, the propagation speed of > differential mode is faster than that of common mode. > In specific, the value of Cm/C is higher than Lm/L in inhomogeneous > microstrip line while the values are same in homogeneous strip line? > > Could somebody let me know why it physically is? > > > Thanks in advance, > Jongbae Park. > > > > -- > --------------------------------------------------------Ph.D Candidate > StudentTerahertz Interconnection & Package Laboratory,Department of > Electrical Engineering, Korea Advanced Institute of Science and Technology > (KAIST),373-1, Kusong-dong, Yusong-ku, Taejon 305-701, > KoreaFax)+82-42-869-8058Tel)+82-42-869-5458Mobile)+82-11-9787-7966E-mail) > pjb77@xxxxxxxxxxxxxxxxxxxxxx URL) > http://tera.kaist.ac.kr/-------------------------------------------------------- > > > ------------------------------------------------------------------ > 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.net > > 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 > > > ------------------------------------------------------------------ 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.net 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