Intrinsic Wave Impedance for Conductive Medium

  • Thread starter tquiva
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Homework Statement


I know that for air, the intrinsic impedance η is 377 Ω, but it becomes complex in a conductive medium. This fact is sort of hindering me in being able to answer a few problems consisting of electric and magnetic waves in a conductive medium, but I just wanted to clarify one thing.
Say, I am given H(z,t)=0.5cos(ωt-βz)ay+0.7cos(ωt-βz)ax

Homework Equations


I know that the intrinsic impedance for a conductive medium is:
attachment.php?attachmentid=40735&stc=1&d=1320639186.png


The Attempt at a Solution


When σ=0 for one problem, I was left with:
attachment.php?attachmentid=40736&stc=1&d=1320639330.png

But I do know that
attachment.php?attachmentid=40738&stc=1&d=1320639449.png


My question is, what in the world is u_o, ε_o, and ε_r ???
Am I supposed to figure this out or is this already provided in a table somewhere?
I have been trying to look in my book and online, but am getting confused easily.
Will someone please clarify this for me?
Any help is greatly appreciated!
 

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Answers and Replies

  • #2
rude man
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Those are all real constants. mu_0 and epsilon_0 are permeability and permittivity of free space, look them up anywhere, and epsilon_r is the relative permittivity of your medium (= epsilon/epsilon_0).

How you got as far as you did, which is pretty far, without knowing that is a bit of a mysrtery to me, and please believe that I'm nort trying to be condescending or insulting - just wondering!
 

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