Page 118 - Electrical Engineering Dictionary

ily small. See also achievable rate region, card a printed circuit board that can be
multiple access channel. plugged into a main board to enhance the
functionality or memory of a computer.
capture effect a phenomenon found in
packet switched networks in which nonequal card cage mechanical device for holding
powers in packet radio networks using con- circuit cards into a backplane.
tention protocols lead to higher throughputs.
In contention protocols used in packet ra- cardinal series the formula by which
dio networks, the transmitted packets are al- samples of a bandlimited signal are interpo-
lowed to collide. If two packets collide and lated to form a continuous time signal.
one is significantly stronger in power, this
packet is more likely to be captured (de- cardinal vowel according to English pho-
tected) by the receiver. netician Daniel Jones, a vowel corresponding
to one of the extreme positions of the vowel
diagram.
capture range the range of input frequen-
cies over which the PLL can acquire phase
carrier amplitude amplitude of the ra-
lock.
dio frequency sinusoid used as a vehicle for
transporting intelligence from the sending
capture register internal register which, end of a communications link to the receiv-
triggered by a specified internal or external ing end. For an AM, FM, or PM wave, the
signal, store or “capture” the contents of an peak amplitude of the spectral component in
internal timer or counter. the frequency domain about which symme-
try exists. The carrier amplitude (as a func-
carbon brush a block of carbon used to tion of time) contains a portion of the intelli-
make an electrical contact to a rotating coil gence for angle modulation ( See frequency
via the commutator of a DC machine or the modulation and phase modulation). In con-
slip rings of a synchronous machine. trast, the carrier amplitude contains no in-
formation for AM or any of the SSB varia-
carbon dioxide (CO 2 ) linear gas tions ( See amplitude modulation and single
molecule consisting of one carbon and two sideband modulation), but is merely used as
oxygenatoms, mediumforanimportantclass a frequency marker.
of lasers.
carrier concentration the number of mo-
bile charge carriers per unit volume, positive
carbon dioxide laser laser in which the
(holes) or negative (electrons). In a semicon-
amplifiying medium is carbon dioxide gas;
ductor, both concentrations are present and
efficient, powerful, and commercially impor-
are modifiable by externally applied electric
tant laser that is pumped and configured in
fields.
many ways and has its principal output lines
in the mid-infrared.
carrier current communication the use
of electric lines to carry communication sig-
carbon resistor thermometer a carbon nals.
resistor whose temperature sensitivity pro-
vides good temperature resolution. carrier frequency in pulse-width-modu-
lated (PWM) switching schemes, the switch-
carcinotron a forward radial traveling ing frequency that establishes the frequency
wave amplifier in which microwave signals at which the converter switches are switched.
are fed to the radial slow wave structure. In sine-triangle PWM, the carrier frequency

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2000 by CRC Press LLC