Multipath
interference is a phenomenon in the physics of
waves whereby a wave from a source travels to a detector via two or more paths and, under the right condition, the two (or more) components of the wave interfere. The condition necessary is that the components of the wave remain
coherent throughout the whole extent of their travel. The interference will arise owing to the two (or more) components of the wave having, in general, travelled a different length, and thus arriving at the detector out of
phase with each other.
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