"A",
"B",
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
Previous set of "B" definitions and terms.
BEAM: See Lobe, antenna.
BEAM, CAPTURE: See Capture Beam.
BEAM, DIVERGENCE: Of an electromagnetic beam, in any plane that intersects the beam axis, the increase
in beam diameter with distance from the aperture from which the beam emerges. Note 1: Beam
divergence is usually used to characterize electromagnetic beams in the optical regime.
BEAMSTEERING: Changing the direction of the main lobe of a radiation pattern. Note: In radio systems,
beam steering may be accomplished by switching antenna elements or by changing the relative phases
of the rf signals driving the elements.
BEAM-TO-BEAM CORRELATION (BBC): BBC is used by frequency scan radars to reject pulse jamming and jamming at a swept frequency. Correlation is made from two adjacent beams (pulses). The receiver rejects those targets (signals) that do not occur at the same place in two adjacent beams.
BEAMWIDTH: See Antenna Beamwidth. In the radio regime, of an antenna
pattern, the angle between the half-power (3-dB) points of the main lobe, when referenced to the peak
effective radiated power of the main lobe.
BEARING RESOLUTION: Ability of a radar to distinguish between targets that are close together in
bearing.
BEAT FREQUENCIES: Difference and sum frequencies which result from combining two different
frequencies.
BEAT FREQUENCY OSCILLATOR (BFO): Any oscillator whose output is intended to be mixed with another
signal to produce a sum or difference beat frequency. Used particularly in reception of CW transmissions.
BIPOLAR VIDEO: Unrectified (pre-detection) IF (both positive and negative portions of the RF envelope) signals that arise from the type of detection and console display employed in pulse Doppler and MTI receivers.
BISTATIC RADAR: A radar using antennas at different locations for transmission and reception.
BLACKBODY: A totally absorbing body that does not
reflect radiation.
BLANKING: In graphic display, the suppression of the display of one or more display elements or display segments. The process of making a channel, or device non-effective for a certain interval. Used for retrace sweeps on CRTs or to mask unwanted signals such as blanking ones own radar from the onboard RWR.
BLOCKING: A condition in an amplifier, caused by over-driving one or more stages, in which the
amplifier is insensitive to small signals immediately after reception of a large signal.
BORESIGHT: The physical axis of a directional
antenna. To align a directional antenna, using either an optical procedure or a fixed target at a
known location.
BROADSIDE ARRAY: An antenna array in which the direction of maximum radiation is
perpendicular to the plane of the array.
BURN-THROUGH RANGE: The ability of a radar to see through jamming. Usually, described as the point when the radar's target return is a specified amount stronger than the jamming signal. (typical values are 6dB manual and 20 dB automatic).
BURST: In data communications, a sequence of
signals, noise, or interference counted as a unit in
accordance with some specific criterion or measure.
