Page 86 - Electrical Engineering Dictionary

to the appropriate terminals of transistors i, j ∈ Z + (the set of nonnegative integers)
(e.g., FETs) without disturbing the AC mi- is said to be bounded-input bounded-output
crowave operation of the circuit. In some (BIBO) stable if for every constant M> 0
cases, “on-chip” DC circuitry needs to be there exist a constant N> 0 such that if
designed so as to provide stable bias volt- ku k,l k≤ M for all k, l ∈ Z + , then ky i,j k≤
m
age/current conditions for the device even N for all i, j ∈ Z + where u k,l ∈ R is the
p
when the chip DC supply voltages vary (due input, y i,j ∈ R is the output, g i,j ∈ R p×m
to weakening batteries, etc.). The other as- is the matrix impulse response of the system
pect of bias network design is to isolate the and kvk denotes a norm of the vector v. The
DC network from interfering with the AC or system is BIBO stable if and only if
RF/microwave operation of the circuit, and
∞ ∞
vice-versa. In a lumped element design, this X X

g i,j < ∞

is generally accomplished by a combination
i=0 j=0
of spiral inductors and MIM capacitors.
BIBS See bounded-input bounded-state
bias voltage or current the DC power
stability.
applied to a transistor allowing it to operate
as an active amplifying or signal generating
BiCMOS integrated circuit technol-
device. Typical voltage levels in GaAs FETs
ogy/process that incorporates bipolar and
used in receivers are 1 to 7 volts between the
complementary metal oxide semiconductor
drain and source terminals, and 0 to −5 volts
devices on the same die.
on, or between, the gate and source termi-
nals. For microwave systems, DC voltages
bicycle a chain-driven drill for boring
and currents, provided by batteries or AC/DC
holes.
converters required to “bias” transistors to
a region of operation where they will either bidirectional bus a bus that may carry
amplify, mix or frequency translate, or gen- information in either direction but not in both
erate (oscillators) microwave energy. Since simultaneously.
energy can be neither created nor destroyed,
microwave energy amplification or creation bi-directional laser a ring laser with both
is accomplished at the expense of DC energy. clockwise and counter-clockwise circulating
waves. Useful as a rotation rate sensor.
biasing thetechniqueofapplyingadirect-
current voltage to a transistor or an active net- bidirectional pattern a microphone
work to establish the desired operating point. pickup pattern resembling a figure eight, in
which the device is most sensitive to sounds
bible nickname for the National Electrical on either side of the pickup element.
Code.
bi-directional resonator a standing-
wave resonator or a ring-resonator in which
BIBO stability See bounded-input
the electromagnetic waves circulate in both
bounded-output stability.
the clockwise and counter-clockwise direc-
tions.
BIBO stability of 2-D linear system a
system described by the equation
bidirectional transducer a surface
acoustic wave (SAW) transducer which
i j
X X launches energy from both acoustic ports
y i,j = g i−k,j−l u k,l which are located at either end of the trans-
k=0 l=0 ducer structure.

c
2000 by CRC Press LLC