Page 91 - Electrical Engineering Dictionary

bipolar memory memory in which a stor- bispectra computation of the frequency
age cell is constructed from bipolar junction distribution of the EEG exhibiting nonlinear
transistors. See also static random access behavior.
memory (SRAM).
bispectrum the Fourier transform of the
bipolar neuron a neuron with a signal triple correlation function. It preserves phase
between −1 and +1. information and uniquely represents a given
process in the frequency domain. It can be
bipolar transistor See bipolar junction used to identify different types of nonlinear
transistor. system response.

bipole DC system with two conductors, BIST See built-in self-test.
one positive and the other negative polarity.
The rated voltage of a bipole is expressed as bistable pertaining to a device with two
±100 kV, for example. stable states. Examples: bistable multivibra-
tor, flip-flop. See also bistable system.
biquad an active filter whose transfer
function comprises a ratio of second-order bistable device See bistable.
numerator and denominator polynomials in
the frequency variable. bistable optical device a device whose
optical transmission can take on two possible
biquadratic transfer function a ratio- values.
nal function that comprises a ratio of second-
order numerator and denominator polynomi- bistable system an optical system where
als in the frequency variable. the transmission can take on two possible val-
ues. See also bistable.
bird’s beak feature seen in cross-
sectional photomicrographs of silicon gate bistatic scattering a measure of the rera-
transistors caused by encroachment of oxide diated power (back-scattered) from an illu-
under the gate. minated target in the direction other than that
of the illuminating source.
birefringence The property of certain
materials to display different values of the bit (1) the fundamental unit of informa-
refractive index for different polarizations of tion representation in a computer, short for
a light beam. “binary digit” and with two values usually
represented by “0” and “1.” Bits are usu-
birefringent fiber optical fiber that ally aggregated into “bytes” (7 or 8 bits) or
has different speeds of propagation for light “words” (12–60 bits).
launched along its (two distinct) polarization A single bit within a word may represent
axes. the coefficient of a power of 2 (in numbers),
a logical TRUE/FALSE quantity (masks and
birefringent material material that can Boolean quantities), or part of a character or
be described by two or more refractive in- other compound quantity. In practice, these
dices along the directions for principle axes. uses are often confused and interchanged.
(2) in Information Theory, the unit of in-
birthmark a stamp on a wooden utility formation. If an event E occurs with a
pole which denotes its manufacturer, date of probability P(E), it conveys information of
manufacture, size, and method of preserva- log (1/P(E)) binary units or bits. When
2
tion. a bit (binary digit) has equiprobable 0 and

c
2000 by CRC Press LLC