-----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Bob Patel Sent: Wednesday, January 23, 2002 2:04 AM To: si_list Subject: [SI-LIST] RLGC matrix Hi! I know this could be a dumb question but let me put it out because somehow I am at loss in figuring it out. I have simulated a transmission line i.e. using the stack up & trace dimensions to come up with the RLGC matrix in HSPICE. Now, should I use Z = sqrt(R+jwl/G+jwC) to calculate Z. And the R, L,C,G values can be calculated by solving the individual matrix in determinant form. -> In case of low frequency or below 1GHz, the R and G is ignored to make it simple. The next question is can I calculate impedance in this way for individual sections because I have three sections: Driver( bond wire length) + trace 1(width = 9mil to achieve 34 ohm)+ Trace 2( width = 5mil to achieve 50ohms).The overall impedance seen by the driver has to be around 34 ohms but I know with the values given above that it won't be so. Hence I am on this path to calculate the impedance of each section and then take the average to calculate Zeffective and also the propagation delay. -> You mean, ---------^^^-----()()()------------ | | > | < = > | | | ------------------------------------ is equal with ---------^^^-----()()()---------------------^^^-----()()()----------------- ----^^^-----()()()------------ | | | | | | > | > | > | < = < = < = > | > | > | | | | | | | ---------------------------------------------------------------------------- -------------------------------- How about using the summation for example, Req=R1+R2+R3, Leq=L1+L2+L3, Ceq=C1+C2+C3, Geq=G1+G2+G3? Then I think the Zeffective = sqrt(Req + jwLeq/Geq + jwCeq). Thanks in advance Bob __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/ ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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