frequency band of emission
1Emission spectrum — The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted by the element s atoms or the compound s molecules when they are returned to a lower energy state. Each element s …
2Spontaneous emission — is the process by which a light source such as an atom, molecule, nanocrystal or nucleus in an excited state undergoes a transition to the ground state and emits a photon. Spontaneous emission of light or luminescence is a fundamental process… …
3Orthogonal frequency-division multiplexing — Passband modulation v · d · e Analog modulation AM · …
4FM broadcast band — The FM broadcast band, used for FM broadcast radio by radio stations, differs between different parts of the world. In Europe and Africa (ITU region 1), it spans from 87.5 to 108.0 megahertz (MHz), while in America (ITU region 2) it goes only… …
5Extremely high frequency — Frequency range 30 to 300 GHz ITU Radio Band Numbers 1 2 3 4 5 6 7 8 9 10 …
680-meter band — The 80 meter or 3.5 MHz band is a core amateur radio frequency band, allocated frequencies from 3.5 to 4.0 MHz in IARU Region 2, and generally 3.5 to 3.8 or 3.9 MHz in Regions 1 and 3 respectively. The portion of the band used for voice… …
7Amateur radio frequency allocations — Amateur radio frequency allocation is done by national telecommunications authorities. Globally, the ITU oversees how much radio spectrum is set aside for amateur radio transmissions. Radio amateurs use a variety of transmission modes, including… …
8Amateur radio frequency bands in India — Amateur radio or ham radio is a hobby that is practised by over 16,000 licenced users in India.cite news|url=http://www.tribuneindia.com/2005/20050304/nation.htm#10|title=Government to promote amateur radio|last=Ramchandran|first=Ramesh|date=2005 …
9Direct and indirect band gaps — In semiconductor physics, the band gap of a semiconductor is always one of two types, a direct band gap or an indirect band gap. The band gap is called direct if the momentum of electrons and holes is the same in both the conduction band and the… …
10High Frequency Active Auroral Research Program — HAARP is often confused with Project HARP, the High Altitude Research Project (a joint project of The Pentagon and the Canadian Department of National Defence).The High Frequency Active Auroral Research Program (HAARP) is an investigation project …
