William, If you want to calculate the impedance, the equation for a lossless line is simply
Z = sqrt(l/c) where l = per unit length inductance c = per unit length capacitance. For lossy line, it gets more complex: Z = sqrt((r+jwl)/(g+jwc)) where unit length parameters are r = resistance (series, as a function of frequency) w = radian frequency g = conductance (line to line) DB > ---------- > From: [email protected][SMTP:[email protected]] > Reply To: [email protected] > Sent: Thursday, January 11, 2001 8:25 AM > To: [email protected] > Subject: RE: Zo > > > My experience is that it is in the order of 75-150 ohms and depends upon the > material, lay and shielding, if any. Increased lay and shielding will reduce > the impedance. > > Richard Woods > > ---------- > From: William D'Orazio [SMTP:[email protected]] > Sent: Thursday, January 11, 2001 9:49 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] > > > ------------------------------------------- > 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] > > ------------------------------------------- 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]
