18WuD2x

matching pad An inductance-capacitance (LC)
network for matching the impedance of a load to
the output impedance of a signal generator.
matching stub See STUB.
matching transformer An audio-frequency (AF) or
radio-frequency (RF) transformer used to match
one purely resistive impedance to another.
matchtone A transistorized, single-frequency audio
oscillator that can be used to monitor transmaster
program file • maxima and minima 435
a data-processing installation. It is also called
master library tape.
master record In a data-processing system, the
current record (usually stored on a disk or tape)
that will be used for the next computer run.
master relay A relay that operates other (slave) relays.
Compare SLAVE RELAY.
master station See KEY STATION.
master switch A switch that can actuate or deactuate
an entire installation or system.
master tape 1. In sound recording and reproduction,
a magnetic tape that contains material from
which other tapes and discs can be made. 2. In
automation, a magnetic tape on which is
recorded the basic signal sequence for controlling
a process and other recorders. 3. In data processing,
a magnetic tape that must not be erased.
master volume control See MASTER GAIN CON-
TROL.
masurium See TECHNETIUM.
MAT Abbreviation of MICROALLOY TRANSISTOR.
match 1. To mate devices, signals, impedances,
etc. for optimum compatibility in terms of signal
transfer, equipment interfacing, and other optimizing
qualities. 2. The condition of being compatibly
mated, physically or electrically.
matched components Circuit components (capacitors,
coils, diodes, resistors, transistors, etc.)
that are carefully selected for similar or particularly
compatible operating characteristics.
matched filter 1. A filter with input and output
impedances matched to the input line and output
load, respectively. 2. A filter designed for separating
a signal with a particular waveform from
other signals and noise.
matched impedance A usually non-reactive
impedance that has the same value as that of another
impedance with which it is operated. Maximum
power is transferred between impedances
that are matched.
matched load A purely resistive load, the impedance
of which is the same as the characteristic
impedance of the feed line. This results in
optimum power transfer from the line to the load.
matched pair A pair of matched components offered
in a single package.
matched transmission line A transmission line
terminated in a purely resistive impedance whose
value is identical to the characteristic impedance
of the line. Such a line transfers all of its energy
to its load without reflection; no standing waves
are on the line.
Voltage (volts)
100
80
60
40
20
0
Gen.
mitted radiotelegraph signals. The carrier wave
from the transmitter is rectified by a small semiconductor
diode, whose direct-current output
powers the oscillator.
Mateucci effect The generation of a potential difference
in a helically wound, ferromagnetic wire
when its magnetization fluctuates.
mathematical check A test of the validity of the
result of an arithmetic process (by using alternate
methods, for example).
mathematical logic 1. A branch of mathematics
that involves the theoretical behavior of various
systems of reasoning. 2. See BOOLEAN ALGE-
BRA. 3. See DIGITAL LOGIC.
mathematical model See MODEL, 2.
mathematical subroutine Within a computer program,
a subroutine serving as an arithmetic function
(i.e., one for performing an operation not
integral to the monitor program).
matrix 1. A high-speed switching or memory array
used in counters and computers. 2. Generally,
any two-dimensional array of objects. 3. A device
for solving linear simultaneous equations, consisting
of a rectangular array of coefficients.
matrix printer See WIRE PRINTER.
mat switch A form of PRESSURE SENSOR used in
some security systems. When weight appears on
the mat, switches close, actuating an alarm.
matter
Voltage
Current
Relative position
Line
(50 ohms)
matched transmission line
The building material of the universe that
occupies space and has mass that can be measured.
See, for illustration, ATOMIC THEORY and
STATES OF MATTER.
matter waves See DE BROGLIE WAVES.
max Abbreviation of MAXIMUM.
maxima Points along a curve at which a function
reaches a local maximum value. Also see MAX-
IMA AND MINIMA.
maxima and minima 1. The loops and nodes of
current or voltage on an antenna or transmission
line. 2. The lobes and nulls in a directivity pattern.
3. The bright and dark bands in a visiblelight
interference pattern. 4. In radar reflections,
regions of localized maximum and minimum
5
4
3
2
1
0
Current (amperes)
Load
(50 ohms)