In message <[email protected]>, dated Wed, 31 Aug 2011, Derek Walton <[email protected]> writes:
>A cable is only its characteristic impedance when fed and terminated in >matching impedance. That's why I said non-perfect impedance of the >cable The characteristic impedance IS an intrinsic property of the cable; the full expression is: Z = sqrt((R+jwL)/G+jwC)), where R, L, G and C are per (the same) unit length. At a sufficiently high frequency, wL>>R and with a sufficiently low-loss dielectric G<<wC, so that Z simplifies to sqrt(L/C). -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
