ticular location may be obtained from mul-
tile transmitters, typically utilizing different
frequency channels. Macro diversity is typi-
cally utilized to overcome the type of signal
fading typically known as shadow fading.
macro shadowing
shadowing due to the
obstacles in the propagation path of the radio
wave. See also
micro shadowing
.
macroinstruction
a short code-like text,
defined by the programmer, that the assem-
bler or compiler will recognize and that will
result in an inline insertion of a predefined
block of code into the source code.
macroprogram
a sequence of macroin-
structions.
macrotiming diagram
a graphical dis-
play showing how the waveforms vary with
time but with a time scale that does not have
sufficient resolution to display the delays in-
troduced by the individual basic elements of
the digital circuit.
MAD
See
maximal area density
.
made electrode
a ground electrode for a
lightning rod which has been especially con-
structed for the purpose, as opposed to using
a building frame or water pipe for the pur-
pose.
magic T
See
magic tee
.
magic T junction
See
magic tee junction
.
magic tee
a combination of E-plane (se-
ries) and H-plane (shunt) tees forming a hy-
brid waveguide junction. Typically used to
split or couple two microwave signals that are
in or out of phase in the same wave guide.
Also called a hybrid tee.
magic tee junction
a four-port microwave
device, that couples the input signal at port 1
equally into ports 2 and 3, but not into port
4. Input signal at port 3 is coupled equally
into ports 1 and 4, but not into port 2, etc. At
microwave frequency, the waveguide junc-
tion that makes up this device involves three
magnetic plane arms and one electric field
plane arm resembling T and hence is called
magic tee junction.
maglev
See
magnetic levitation
.
magnet
any object that can sustain an ex-
ternal magnetic field.
magnetic actuator
any device using a
magnetic field to apply a force.
magnetic bearing
a component of a ma-
chine that uses magnetic force to provide
non-contact support for another component
moving relative to it.
magnetic bias
a constant magnetic field
on which is superimposed a variable, often
sinusoidal, perturbation magnetic field in de-
vices like magnetic bearings.
magnetic brake
any device using a mag-
netic field to retard motion.
magnetic charge density
a fictitious
source of the electromagnetic field that quan-
tifies the average number of discrete mag-
netic charges (also fictitious) per unit volume.
The magnetic charge density is often intro-
duced in problems where duality and equiv-
alence concepts are employed.
magnetic circuit
the possible flux paths
within a system consisting of a source of flux
(electromagnets, permanent magnets), per-
meable flux carrying materials (steel, nickel)
and non-flux carrying materials (aluminum,
air).
magnetic clamp
a device employing a
magnetic field to deliver a clamping action.
magnetic core memory
a persistent, di-
rectly addressable memory consisting of an
c
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