What does impedance of a cable represent?

[houly]

Hello,
I would want to know if the characteristic impedance is only dependant on L and C parameter of a cable ...? does it also depedent on the frequency ?
I don't understand how I can consider a transmission line in impedance term, in fact, if I take a 50 ohm cable (coax for example), what the characteristic impedance of the cable represent ? can i consider that is the "equivalent" impedance between the copper core and the copper shield ?
How can I do to verify the impedance of a cable ?

I hope that you could help me.
Thanks

 

[FvM]

Re: Impedance of a cable

I suggest Lessons In Electric Circuits -- Volume II (AC) - Table of Contents chapter 14 Transmission lines.

 

[houly]

Re: Impedance of a cable

Hello FvM thanks for your link. I'm going to take a look at it.