出典:Wikipedia
出典:『Wikipedia』 (2011/06/17 07:59 UTC 版)
In optics and radio communications (indeed, in any situation involving the radiation of waves, which includes electrodynamics, acoustics, and gravitational radiation), a Fresnel zone (
/freɪˈnɛl/ fray-nel), named for physicist Augustin-Jean Fresnel, is one of a (theoretically infinite) number of concentric ellipsoids which define volumes in the radiation pattern of a (usually) circular aperture. Fresnel zones result from diffraction by the circular aperture.