Metal's Effect on RF: Attenuation, Reflection, Absorption?

[jastewart]

What is the exact effect that metal has on rf (any electromagnetic waveform)? Is it attenuation, reflection, absorption or all of the these?

 

[Simon Bridge]

Welcome to PF;
I cannot be exact because that would depend on the type of metal and the geometry.
... since you extend to all EM waves, then it also depends on the wave.

The short answer, though, is "all of the above".
You can also get EM waves in a conductor.

 

[jastewart]

Thanks...

 

[jastewart]

Water's effect on rf

Does water distort rf? Is this similar to the way the water distorts light?

 

[Simon Bridge]

Yes it can - water forms a dielectric material.
It can also absorb some frequncies ... look up absorption spectrum of water.

 

[jastewart]

Thanks...

 

[jastewart]

Now I'm curious about something... thought that water was a conductor of electricity not an insulator. Is it the polarization of the waveform that makes water "conductive?"

 

[jastewart]

never mind, found out...pure water is an insulator (no free electrons - balanced molecule - it's the impurities in water that allow for conduction. please correct if wrong...

 

[Simon Bridge]

Yeah - liquid water is quite complicated, even when it is "pure".

BTW: you'll be aware that water (ice) buildup on antennas can have a big effect, and submarines don't use radar (and have to float a buoy to use radio).

 

[jastewart]

Dude, you rock...thanks...