For an electromagnetic wave, coherence time is the time over which a propagating wave may be considered coherent.
Note 1: Coherence time In long-distance transmission systems, the coherence time may be reduced by propagation factors such as dispersion, scattering, and diffraction.
Note 2: In optical communications, coherence time, τ, is calculated by dividing the coherence length by the phase velocity of light in a medium; approximately given by τ = λ2/(cΔλ) where λ is the central wavelength of the source, Δλ is the spectral width of the source, and c is the velocity of light in vacuum.
Note 3: "Coherence time" is usually applied to the optical regime.
Source: from Federal Standard 1037C and from MIL-STD-188
Electronics Topics
The field of electronics is the study and use of systems that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves and semiconductors. The design and construction of electronic circuits to solve practical problems is part of the fields of electronic engineering, and the hardware design side of computer engineering. The study of new semiconductor devices and their technology is sometimes considered as a branch of physics.
# - A | B | Co - Cz | C - Cm | D
Em - F | E - El | G - H | I - K | L - Ma
