"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 "L" Terms and definitions
LOGIC. The basic principles and applications of truth tables, interconnections of off-on circuit elements,
and other factors involved in mathematical computation in automatic data processing systems and other
devices.
LOGIC CIRCUIT. The primary control information processor in digital equipment; made up of electronic
gates and so named because their operation is described by simple equations of a specialized logic
algebra.
LOGIC DIAGRAM. In computers and data processing equipment, a diagram representing the logical
elements and their interconnections without necessarily expressing construction or engineering details.
LOGIC ELEMENT. The smallest building blocks that can be represented by operators in an appropriate
system of symbolic logic. Typical logic elements are the AND-gate and the flip-flop, which can be
represented as operators in a suitable symbolic logic. Also a device that performs the logic function.
LOGIC INSTRUCTION. Any instruction that executes a logic operation that is defined in symbolic
logic, such as AND, OR, NAND, or NOR.
LOGIC OPERATION. A non-arithmetical operation in a computer, such as comparing, selecting, making
references, matching, sorting, and merging, where the logical YES or NO quantities are involved.
LOGIC SWITCH. A diode matrix or other switching arrangement that is capable of
directing an input signal to one of several outputs.
LOGIC SYMBOL. A symbol used to represent a logic element graphically. Also a symbol used to
represent a logic operator.
LONGITUDINAL WAVES. Those waves in which the disturbance (back and forth motion) takes place in
the direction of propagation. Sometimes called compression waves.
LONG-WIRE ANTENNA. An antenna that is a wavelength or more long at its operating frequency.
LOOP. A curved conductor that connects the ends of a coaxial cable or other transmission line and
projects into a waveguide or resonant cavity for the purpose of injecting or extracting energy.
LOOSE COUPLING. Inefficient coupling of energy from one circuit to another that is desirable in some
applications. Also called weak coupling.
LOWER-FREQUENCY CUTOFF. The lowest frequency a circuit will pass.
LOWER SIDEBAND. All difference frequencies below that of the carrier.
LOWEST REPLACEABLE UNIT. An LRU is the lowest possible unit to be replaced within the system component during site level
maintenance activities. It is a separate, installable physical package performing a single function
or group of closely related functions.
LOWEST USABLE FREQUENCY. The minimum operating frequency that can be used for
communications between two points.
LOW FREQUENCY. The band of frequencies from 30 kHz to 300 kHz.
LOW-LEVEL MODULATION. Modulation produced in an earlier stage than the final.
LOW-NOISE AMPLIFIER. See PREAMPLIFIER.
LOW-PASS FILTER. A filter that passes a majority of the low frequencies on to the next circuit and
rejects, or attenuates, the higher frequencies. Also called a high-frequency discriminator.
LUMPED CONSTANTS. The properties of inductance, capacitance, and resistance in a transmission line.
LUMPED IMPEDANCE TUNING. The insertion of an inductor or capacitor in series with an antenna to
electrically lengthen or shorten the antenna.
"M" Terms
