Page 129 - Electrical Engineering Dictionary

nel. C ∞ is the capacity of the infinite band- ing and mounting medium, as applicable.
width white Gaussian noise channel, defined

as T channel − T case
θ cc =
P av P w
C ∞ = bit/s . equilibrium
N o ln2
channel robust vector quantization channelizer a system that decomposes an
a vector quantizer that has been made ro- RF signal into narrow-band output channels;
bust against channel errors. See also noisy term often applied to acousto-optic spectrum
channel VQ. analyzers that are driven by RF frequency
signals. See also acousto-optic spectrum
channel robust VQ See channel robust analyzer.
vector quantization.
chaos (1) erratic and unpredictable dy-
channel sounding the act of recording namic behavior of a deterministic system that
from a real, physical channel a selected set of never repeats itself. Necessary conditions for
characteristics describing the channel. This a system to exhibit such behavior are that it be
involves transmitting a known signal to the nonlinear and have at least three independent
channel under study, and at the receiver pro- dynamic variables.
cessing the received signal to extract the re- (2) in microelectronics, deterministic mo-
quired information, typically the impulse re- tion, in which the statistics are essentially
sponse or the transfer function of the channel. those of a Gaussian random process.

channel spill leakage of RF energy from chaotic behavior a highly nonlinear state
a radio channel n into a radio channel n ± i, inwhichtheobservedbehaviorisverydepen-
i ≥ 1, due to finite channel filter attenuation dent on the precise conditions that initiated
outside of the bandwidth of n. the behavior. The behavior can be repeated
(i.e., it is not random), but a seemly insignif-
channel step See frequency synthesizer. icant change, such as voltage, current, noise,
temperature, rise times, etc., will result in
channel subsystem the I/O processing dramatically different results, leading to un-
component of a computer system conforming predictability. The behavior may be chaotic
to the channel architecture model. under all conditions, or it may be well be-
haved (linear to moderately nonlinear) un-
channel waveguide a light guide that is til some parametric threshold is exceeded, at
either raised above or diffused into a sub- which time chaotic behavior is observed. In a
strate. mildly chaotic system, noticeable deviations
resulting from small changes in the initial
channel-to-case thermal resistance the conditions may not appear for several cycles
proportionality constant (denotedθ cc ) atther- or for relatively long periods. In a highly
mal equilibrium between the temperature dif- chaotic system, the deviations are immedi-
ference of the FET channel (T channel ) and a ately apparent.
specified case surface (T case ) to the dissipated
power in the channel (P w ), in units of C/W. character (1) letter, number or symbol
◦
The specified surface is usually the most ef- as used on a computer keyboard.
fective in reducing the temperature. It in- (2) data type that represents an alphanu-
cludes the thermal resistance of the chip, die meric character as a group of bits, usually as
attach material (solder or adhesive), packag- an eight-bit byte.

c
2000 by CRC Press LLC