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BANDPASS FILTER—A filter that allows a narrow band of frequencies to pass through the circuit.
Rejects or attenuates frequencies that are either higher or lower than the desired band of frequencies [9]
[16].
BAND-REJECT FILTER—A tuned circuit that does not pass a specified band of frequencies [9] [16].
BANDWIDTH—The difference between the highest usable frequency of a device (upper frequency limit)
and the lowest usable frequency of the device (lower frequency limit) - measured at the half-power
points [8] [9] [12] [15].
BARRETTER—A type of bolometer characterized by an increase in resistance as the dissipated power
rises [16].
BASE—The element in a transistor that controls the flow of current carriers [7].
BASE—(1) A reference value. (2) A number that is multiplied by itself as many times as indicated by an
exponent. (3) Same as radix. (4) The region between the emitter and collector of a transistor that
receives minority carriers injected from the emitter. It is the element that corresponds to the control grid
of an electron tube [13].
BASE-INJECTION MODULATOR—Similar to a control-grid modulator. The gain of a transistor is
varied by changing the bias on its base [12].
BATTERY—A device for converting chemical energy into electrical energy [1].
BATTERY CAPACITY—The amount of energy available from a battery. Battery capacity is expressed in
ampere-hours [1].
BAUD—A measurement of speed based on the number of code elements or units per second [17].
BAY—Part of an antenna array [10].
BEAM—See LOBE [18].
BEAM-LEAD CHIP—Semiconductor chip with electrodes (leads) extended beyond the wafer [14].
BEAM-POWER TUBE—An electron tube in which the grids are aligned with the control grid. Special
beam-forming plates are used to concentrate the electron stream into a beam. Because of this action, the
beam-power tube has high power-handling capabilities [6].
BEARING—An angular measurement of the direction of an object from a reference direction, such as true
north [11].
BEARING RESOLUTION—Ability of a radar to distinguish between targets that are close together in
bearing [18].
BEAT FREQUENCIES—Difference and sum frequencies, which result from the combination of two
separate frequencies [18].
BEAT FREQUENCY—The difference between the oscillator frequency and the unknown audio frequency
[16].
BEAT-FREQUENCY OSCILLATOR—An additional oscillator used in a receiver when it is receiving a
cw signal. It provides an audible tone [17].
