Zo= eta(free space)/ (pi * sqrt(epsilon effective) * inversecosh (D/d) where epsilon effective is = 1 + (.25 + 0.0004 theta^2)*(epsilon of insulation-1.)
use 0.001 instead of 0.0004 for soft insulation theta= inversetan( twists per length * pi * D) D= diameter of coductor + insulator d = diameter of conductor I am attaching a Powerpoint file that should help <<twistedpairzo.ppt>> Vicente RodrÃguez, Ph.D., E.I.T. RF/Electromagnetics Engineer ETS-Lindgren (an ESCO Company) P.O.Box 80589, Austin TX 78708-0589 phone 512.835.4684 x648 fax 512.835.4729 [email protected] http://www.emctest.com http://home.austintx.com/~vicenter > -----Original Message----- > From: William D'Orazio [SMTP:[email protected]] > Sent: Thursday, January 11, 2001 8:49 AM > To: EMC Posting (E-mail) > Subject: Zo > > > Does anybody know the characteristic impedance of a twisted pair? > Thanks in advance, > > <<...OLE_Obj...>> > > William D'Orazio > CAE Electronics Ltd. > Electrical System Designer > > Phone: (514) 341-2000 (X4555) > Fax: (514)340-5552 > Email: [email protected] > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] >
twistedpairzo.ppt
Description: MS-Powerpoint presentation
