Hi All! Consider a EM structure with 4 layers of dielectric. layer 1 air layer 2 dielectric layer 3 dielectric layer 4 dielectric top and botton are grounded. if i draw a rectangular conductor in layer 3(say) how do i calculate the characteristic impedane for the port termination. do i consider it as a stripling or a microstrip. i will be gald if anyone could anwer my question. - vijay ------------------------------------------------------------------ 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 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