fresnel region การใช้

The radiative near field ( also called the " Fresnel region " ) covers the remainder of the near-field region, from out to the Fraunhofer distance.
Hence, even though one would expect minimal change in phase in the first Fresnel region, the bounced signal will arrive out-of-phase, which will weaken the received signal.
Both sites have line-of-sight to Kilvey Hill, but the direct signal to the Pontardawe site does have a close encounter with a wooded hillside 2 km away which severely intrudes into the signal's First Fresnel Region.
The radiative near field ( sometimes called the "'Fresnel region "') does not contain reactive field components from the source antenna, since it is so far from the antenna that back-coupling of the fields becomes out of phase with the antenna signal, and thus cannot efficiently store and replace inductive or capacitive energy from antenna currents or charges.