extremely high frequencies

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• Extremely high frequency — Frequency range 30 to 300 GHz ITU Radio Band Numbers 1 2 3 4 5 6 7 8 9 10 …   Wikipedia

• High Electron Mobility Transistor — HEMT stands for High Electron Mobility Transistor, and is also called heterostructure FET (HFET) or modulation doped FET (MODFET). A HEMT is a field effect transistor incorporating a junction between two materials with different band gaps (i.e. a …   Wikipedia

• High-gain antenna — The high gain antenna (HGA) is an antenna with a focused, narrow radiowave beam width. This narrow beam width allows more precise targeting of the radio signal also known as a directional antenna. Most commonly referred to during space missions,… …   Wikipedia

• High 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 …   Wikipedia

• Ultra high frequency — (UHF) designates a range (band) of electromagnetic waves with frequencies between 300 MHz and 3 GHz (3,000 MHz). Also known as the decimeter band or decimeter wave as the wavelengths range from ten to one decimeters. Radio waves with frequencies… …   Wikipedia

• Super high frequency — (or SHF) refers to radio frequencies (RF) in the range of 3 GHz and 30 GHz. Also known as the centimeter band or centimeter wave as the wavelengths range from ten to one centimeters.DescriptionThe International Telecommunication Union (ITU), an… …   Wikipedia

• cetacean — cetaceous, adj. /si tay sheuhn/, adj. 1. belonging to the Cetacea, an order of aquatic, chiefly marine mammals, including the whales and dolphins. n. 2. a cetacean mammal. [1830 40; < NL Cetace(a) name of the order (see CET , ACEA) + AN] * * *… …   Universalium

• Johnson–Nyquist noise — (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied… …   Wikipedia

• Heterostructure barrier varactor — diode The Heterostructure barrier varactor (HBV) diode was invented by Erik Kollberg together with Anders Rydberg in 1989 at Chalmers University of Technology. This semiconductor diode has an anti symmetric current voltage relationship and a… …   Wikipedia

• acorn tube — noun a small vacuum tube; used at high frequencies • Hypernyms: ↑tube, ↑vacuum tube, ↑thermionic vacuum tube, ↑thermionic tube, ↑electron tube, ↑thermionic valve * * * noun : a very small vacuum tube resembling an acorn in shape and used a …   Useful english dictionary

• magnetron — /mag ni tron /, n. Electronics. a two element vacuum tube in which the flow of electrons is under the influence of an external magnetic field, used to generate extremely short radio waves. [1920 25; MAGNE(TO) + TRON] * * * ▪ electronics… …   Universalium