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Technical
Glossary - G
| A
| B | C
| D | E
| F | G | H
| I | J,K
| L | M
| N | O
| P | Q
| R | S
| T | U,V
| W,X,Y,Z | Spec.
Char., Number |
g
(See "conductance")
G
(See "giga")
GaAs
Field Effect Transistor
A field effect transistor made with gallium arsenide.
Gain
Gain is the ratio between the amplitude of the
output signal of a device or circuit compared
to the amplitude of the input signal. Gain is
normally expressed in decibels (dB). A number
of factors may affect the measured gain, so it
is often necessary to specify the conditions or
methods of measurement.
Gain
Control
Part of an amplifier to which a control signal
is applied to vary the gain of the amplifier.
The ability to externally vary the gain of an
amplifier.
Gate
The terminal of a field effect transistor that
controls the resistance of the channel through
the application of an electric field established
between the gate and the source as a result of
an externally-applied voltage. The gate corresponds
to the base of a bipolar transistor.
giga
A prefix that indicates a factor of 109 (one billion),
abbreviated as "G." Giga is a French
prefix, and should be pronounced "jeegah,"
at least when in France.
Glass
Microwave Integrated Circuit
A technology invented and patented by M/A-COM
to produce microwave integrated circuits, consisting
of a glass wafer that is laminated to a silicon
wafer. Various materials are deposited in succeeding
layers on top of the glass wafer, which are then
selectively removed using photolithographic masking
and etching techniques to form lumped element
and transmission line components. Semiconductor
dice that contain discrete transistors, diodes
or integrated circuits can be mounted on the GMIC"
substrate as required by the design.
GMIC
(See "glass microwave integrated circuit")
GPRS
General Packet Radio Service.
GPS
Global Positioning System.
Group
Delay
The first derivative of the phase versus frequency
response of a network, component, or transmission
line.
GSM
Global System for Mobile Communication. The world's
most widely used mobile system, based primarily
on TDMA transmission, operating around 900 MHz
or 1800 MHz in Europe, Asia and Australia, and
around 1800 MHz in the Americas.
Gunn
Effect
In some materials (III-V compounds such as GaAs
and InP), after an electric field in the material
reaches a threshold level, the mobility of electrons
decrease as the electric field is increased, thereby
producing negative resistance. A two-terminal
device made from such a material can produce microwave
oscillations, the frequency of which is primarily
determined by the characteristics of the specimen
of the material and not by any external circuit.
The Gunn Effect was discovered by J. B. Gunn of
IBM in 1963.
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