From: pcdhSpamMeSenseless@electrooptical.net   
      
   On 2020-10-14 16:58, Tom Del Rosso wrote:   
   > As the story goes, the E field starts with high impedance and it goes   
   > down until it's equal to the H field impedance in the far field. It's   
   > just so counter-intuitive that impedance would go down as you get   
   > farther from the source. Is there a somewhat intuitive way to look at   
   > that?   
   >   
   > On another matter, I've asked before about the disagreement between some   
   > books with diagrams of E and M in phase and some books showing them 90   
   > degrees out of phase. Now I found one source that says they're in phase   
   > in the near and 90 degrees in the far.   
   >   
   >   
      
   For a propagating wave in a lossless medium, E and H are in phase. If   
   the medium is isotropic, they're also orthogonal.  In the near field it   
   varies depending on the situation, e.g. between a waveguide horn and a   
   wire antenna.   
      
   The only wave impedance I know about is sqrt(E/H).   
      
   Cheers   
      
   Phil Hobbs   
      
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   Dr Philip C D Hobbs   
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