39210 IEEE Dictionary IEEES
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`INTERACTIVE
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`IEEE 100
`The Authoritative Dictionary of
`IEEE Standards Terms
`
`Seventh Edition
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`Published by
`Standards Information Network
`IEEE Press
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`39210 IEEE Dictionary IEEES
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`INTERACTIVE
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`39210 IEEE Dictionary IEEES
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`BATCH
`
`gate electric contact
`
`477
`
`Gaussian system
`
`gate electric contact See: car-door contact.
`gate limit (speed governing system, hydraulic turbines) A
`device which acts on the governor system to prevent the tur-
`bine-control servomotor from opening beyond the position
`for which the device is set.
`(PE/EDPG) [5]
`gate nontrigger current (thyristor) The maximum gate current
`that will not cause the thyristor to switch from the OFF state
`to the ON state. See also: principal current; gate trigger cur-
`rent.
`(IA/ED/CEM) 223-1966w, [62], [58], [46]
`gate nontrigger voltage (thyristor) The maximum gate voltage
`that will not cause the thyristor to switch from the OFF state
`to the ON state. See also: gate trigger voltage; principal volt-
`age-current characteristic.
`(IA/ED/CEM) 223-1966w, [46], [58], [62]
`gate power closer See: car-door closer.
`gate protective action (thyristor converter) Protective action
`that takes advantage of the switching property in the converter
`protection network.
`(IA/IPC) 444-1973w
`gate suppression (thyristor power converter) Removal of gat-
`ing pulses.
`(IA/IPC) 444-1973w
`gate terminal (thyristor) A terminal that is connected to a gate.
`See also: anode.
`(IA/ED/CEM) 223-1966w, [46], [58]
`gate trigger current (thyristor) The minimum gate current re-
`quired to switch a thyristor from the OFF state to the ON
`state. See also: principal current.
`(IA/ED/CEM) 223-1966w, [62], [58], [46]
`gate trigger voltage (thyristor) The gate voltage required to
`produce the gate-trigger current. See also: principal voltage-
`current characteristic.
`(IA/ED/CEM) 223-1966w, [58], [46], [62]
`gate turn-off current (gate turn-off thyristor) The minimum
`gate current required to switch a thyristor from the ON state
`to the OFF state. See also: principal current.
`(IA/ED/CEM) 223-1966w, [46], [58], [62]
`gate turn-off voltage (gate turn-off thyristor) The gate volt-
`age required to produce the gate turn-off current. See also:
`principal voltage-current characteristic.
`(IA/ED/CEM) 223-1966w, [58], [46], [62]
`gate voltage (thyristor) The voltage between a gate terminal
`and a specified main terminal. See also: principal voltage-
`current characteristic.
`(IA/ED/CEM) 223-1966w, [62], [46], [58]
`gateway A functional unit that interconnects a local area net-
`work (LAN) with another network having different higher
`layer protocols.
`(LM/C) 8802-6-1994
`(2) (A) A dedicated computer that attaches to two or more
`networks and that routes packets from one to the other. (B) In
`networking, a device that connects two systems that use dif-
`ferent protocols. Contrast: bridge. See also: router; mail gate-
`way.
`(C) 610.7-1995
`gather write A write operation in which information from non-
`adjacent storage areas is placed into a single physical record.
`Contrast: scatter read.
`(C) 610.10-1994w
`gating (1) The process of selecting those portions of a wave that
`exist during one or more selected time intervals or that have
`magnitudes between selected limits. See also: wavefront;
`modulation.
`(AP/ANT) 145-1983s
`(2) The application of enabling or inhibiting pulses during
`part of a cycle of equipment operation.
`(AES) 686-1997
`gating signal (keying signal) A signal that activates or deacti-
`vates a circuit during selected time intervals.
`(PE/EEC) [119]
`gating techniques (thyristor) Those techniques employed to
`provide controller (thyristor) gating signals.
`(IA/IPC) 428-1981w
`gauss (centimeter-gram-second electromagnetic-unit sys-
`tem) The gauss is 10⫺4 webers per square meter or one max-
`well per square centimeter.
`(Std100) 270-1966w
`Gaussian beam (1) (fiber optics) A beam of light whose elec-
`tric field amplitude distribution is gaussian. When such a
`beam is circular in cross section, the amplitude is E (r) ⫽ E
`
`(0) exp [⫺(r /w)2] where r is the distance from beam center
`and w is the radius at which the amplitude is 1/e of its value
`on the axis; w is called the beamwidth. See also: beam di-
`ameter.
`(Std100) 812-1984w
`(2) (laser maser) A beam of radiation having an approxi-
`mately spherical wave front at any point along the beam and
`having transverse field intensity over any wave front that is a
`Gaussian function of the distance from the axis of the beam.
`(LEO) 586-1980w
`Gaussian density function (radar) Sometimes referred to as
`normal probability distribution, the Gaussian probability-den-
`sity function is given by
`1
`␴ 2␲p
`Often used to describe statistical nature of random noise,
`where ␴ ⫽ standard deviation.
`(AES/RS) 686-1982s
`Gaussian distribution A probability distribution characterized
`by the probability density function
`(x ⫺ m)
`2
`1
`2␲ ␴
`
`f(X) ⫽
`
`exp ⫺冉 冊22␴
`
`2
`x
`
`f(x) ⫽
`
`p
`
`exp ⫺冋
`
`册22␴
`
`where
`x ⫽ the random variable
`m ⫽ the mean
`␴ ⫽ the standard deviation
`The Gaussian distribution is often used for analytical mod-
`eling of radar noise and various measurement errors. Syn-
`onym: normal distribution.
`(AES) 686-1997
`Gaussian filter A polynomial filter whose magnitude-frequency
`response approximates the ideal Gaussian response, the de-
`gree of approximation depending on the complexity of the
`filter. The ideal Gaussian response is given by
`
`H(j␻) ⫽ exp [⫺0.3466(␻/␻ ) ]
`2
`c
`
`冨
`冨
`where ␻c 3 dB frequency. Gaussian filters, because of their
`good transient characteristics (small overshoot and ringing),
`find applications in pulse systems.
`(CAS) [13]
`Gaussian frequency shift keying (GFSK) A modulation
`scheme in which the data is first filtered by a Gaussian filter
`in the baseband and then modulated with a simple frequency
`modulation.
`(C/LM) 8802-11-1999
`Gaussian noise Noise characterized by a wide frequency range
`with regard to the desired signal of communication channel,
`statistical randomness, and other stochastic properties.
`(C) 610.7-1995
`Gaussian pulse (1) (fiber optics) A pulse that has the waveform
`of a gaussian distribution. In the time domain, the waveform
`is
`f(t) ⫽ A exp [⫺(t/a) ]
`2
`where A is a constant, and a is the pulse half duration at the
`1/e points. See also: full width (duration) half maximum.
`(Std100) 812-1984w
`(2) A pulse shape tending to follow the Gaussian curve cor-
`responding to A(t) ⫽ e⫺a(b ⫺ t)2. See also: pulse.
`(IM/HFIM) [40]
`
`Gaussian random noise See: random noise.
`Gaussian response (1) (amplifiers) A particular frequency-re-
`sponse characteristic following the curve y(f ) ⫽ e⫺af 2. Note:
`Typically, the frequency response approached by an amplifier
`having good transient response characteristics. See also: am-
`plifier.
`(IM/HFIM) [40]
`(2) (oscilloscopes) (amplifiers) A particular frequency re-
`sponse characteristic following the curve
`2⫺af
`y(f) ⫽ e
`Typically, the frequency response approached by an amplifier
`having good transient response characteristics.
`(IM) 311-1970w
`Gaussian system (units) A system in which centimeter-gram-
`second electrostatic units are used for electric quantities and
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