A Bounded Source Cannot Emit a Unipolar Electromagnetic Wave
نویسندگان
چکیده
This problem was first discussed by Stokes over 150 years ago [1, 2, 3, 4], who noted that three-dimensional sound waves from a bounded source cannot be unipolar. While his argument applies to electromagnetic waves as well, this is little recognized in the literature. One-dimensional electromagnetic (and sound) waves can be unipolar. A plane wave can have any pulseform, but, strictly speaking, a plane wave can only be generated by an unbounded source. A well-known pedagogic example given in sec. II-20 of [5] is based on this case. Hence, this old problem still has a new flavor. Here, we offer two new solutions, followed by discussion.
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