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Technical
Glossary - B
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| W,X,Y,Z | Spec.
Char., Number |
Balanced
Mixer
(1) A type of mixer that forms from two signals
A and B third signal C having the form C = (a
+ A)(b + B). "Single balanced" implies
a = 0, and b ¹ 0. "Double balanced"
implies a = b = 0. Such mixers can suppress an
RF carrier and / or local oscillator in their
output spectrum. (2) A hybrid junction circuit
with nonlinear impedances, typically Schottky
diodes or FET's, driven by a single RF source
and a local oscillator (LO) source to produce
an intermediate frequency (IF) signal.
Balanced
Transmission Line
A transmission line or circuit in which two branches
are electrically alike and symmetrical with respect
to a common reference point, usually ground. An
applied signal at the input relative to the reference
leads to signals at equivalent points in the circuits
that have opposite polarity and equal amplitude.
Balun
A transformer circuit that couples a balanced
transmission line to an unbalanced transmission
line.
Band
Pass Filter
A reactive circuit which rejects signals whose
frequencies are outside of its passband 3 dB point
frequencies and propagates signals whose frequencies
are within the 3 dB point frequencies.
Band
Reject Filter
A reactive circuit that rejects signals whose
frequencies are within its 3 dB point frequencies
and propagates signals whose frequencies are outside
its 3 dB point frequencies.
Bandwidth
The frequency interval of interest, or the pass
band of a device or system.
Barrier
Height
The difference between the metal work function
and the semiconductor electron affinity in a rectifying
metal-semiconductor junction (see Schottky diode).
The barrier height of a Schottky junction determines
the voltage current characteristics of that diode.
This can be important because it determines the
local oscillator power necessary to bias the junction
to its optimum non-linear operating point. As
an approximation, the optimum local oscillator
power will increase as the square of the barrier
height, if the same mixer circuit characteristics
and junction capacitance values are used.
Base
The region of a bipolar transistor that separates
the emitter and collector regions. Majority carriers
injected into the base from an external source
controls the amount of current that flows in the
emitter and collector regions.
Base
Current
The current that flows into the base of a bipolar
transistor.
Base
Transceiver Station (or Base Station)
A high power transceiver, typically located at
the geometric center of a cell, which links subscriber
radios such as cellular phones or modems to the
landline communication infrastructure.
Beam
Lead
(1) A metallized termination that extends
beyond the edge of a semiconductor die. (2) A
semiconductor die with metallized terminations
that extend from the edges of the die. A beam
lead device is mechanically and electrically attached
to a circuit by means of these leads.
Bel
The common logarithm of the ratio of two amounts
of power. The abbreviation for Bel is "B."
If P1/P2 is the ratio of two powers, then this
ratio expressed in Bels, N, is N = log10 (P1/P2).
BER
(See "Bit Error Rate").
Bias
The control voltage and/or current applied to
a device that establishes or facilitates proper
operation.
Bias
Current
The (typically direct) current applied to
an electronic device to control or facilitate
its operation.
BiCMOS
A silicon process for fabricating integrated circuits
that combine bipolar transistors and complementary
metal oxide semiconductor devices on the same
chip. The bipolar transistors provide high speed
and can drive loads external to the IC, while
the CMOS devices provide very high density and
low power dissipation. Devices or IC's that use
this process.
Bilateral
A circuit or component whose operation is unchanged
when the input and output ports are interchanged
Bipolar
Of or pertaining to two opposite polarities.
Bit
Error Rate
The ratio of the number of bits in a data transmission
that are incorrectly received to the number of
bits received. The acronym for bit error rate
is BER. The BER is typically expressed in parts
per million.
Bluetooth
A transmission standard operating at 2.4 GHz for
connecting telephones, computers and other devices
without the use of wires.
Bond
Pull
A test used to determine the integrity of a wire
bond, in which mechanical stress is applied to
the wire in the direction that would pull it from
the semiconductor bonding area. Bond pull tests
can destroy the wire bond, in which case the wire
is pulled until it breaks or pulls free from the
bonding area, or nondestructive, in which case
a fixed amount of force is applied to the wire.
Bond
Wire
A conductive wire that connects a semiconductor
die to an external circuit.
Bonding
The very low resistance fusion of a conductive
wire to a metallized area of a semiconductor die.
For most RF/microwave semiconductors, the wire
and the topmost layer of metal on the semiconductor
die are very pure gold (Au).
Bonding
Area
A metallized region on the top surface of semiconductor
die by which electrical connection to an external
circuit is made by means of a bond wire.
Bonding
Pad
(See "bonding area").
BPF
(See 'Band Pass Filter").
BPSK
Binary Phase Shift Key modulation.
Breakdown
Voltage
The reverse voltage at which avalanche breakdown
occurs in a semiconductor.
BRF
(See 'Band Reject Filter").
Bridging
The act of connecting a (typically) high input
impedance device in shunt across a transmission
line or signal path to monitor or sample a signal.
BTS
Base transceiver station, or cellular base station
for a wireless telephone system.
Burnout
The failure mode in a device that is induced by
excessive power dissipation in the device.
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