why do EM waves reflect? what is happening on the material? could anyone draw me a diagram of how the EM wave of a dipole antenna reflects off a surface?
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1https://live-qa.ocw.mit.edu/courses/6-007-electromagnetic-energy-from-motors-to-lasers-spring-2011/6e5c4b74150da32c3b98964855bbdccb_MIT6_007S11_lec29.pdf – anna v Jan 26 '23 at 05:44
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Simplest way to think of it: when an EM wave collides with a piece of metal, it induces a current to flow in the surface of the metal which radiates away another EM wave moving in the opposite direction.
niels nielsen
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Model the electric field of a set of charges next to a bulk conductor (say x<0 is a perfect conductor, and x>0 is the vacuum where you have your charges).
From E+M 1, you know the electric field on the surface of the conductor is 0, so the easy trick is to model this problem with a set of "mirror-image charges" on the conducting side that exactly cancels out the fields from your charge distribution. It's a perfect mirror copy.
So now instead of a set of charges, model your E+M wave traveling towards a conductor. This creates a "mirror" electric field on the inside of the conductor that perfectly cancels out your field at x=0. It also propagates towards x=0, which causes the reflection you see.
Additional reading: https://en.wikipedia.org/wiki/Method_of_images
AlexQueue
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