"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.
NOT Logic Gate
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.
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.
LOSS. The signal reduction due to attenuation. The loss of a signal.
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. Refer to the entry on Passive Filters. A via in a Printed Circuit Board [PCB] also acts as a low pass filter. Related definitions; PCB Definitions.
Passive RC Low Pass Filter
LOW POWER FM RADIO. [LPFM] A broadcast service that permits the licensing of 50-100 watt FM radio stations within a service radius of up to 3.5 miles and 1-10 watt FM radio stations within a service radius of 1 to 2 miles.
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
