MAGIC-T JUNCTIONA combination of the
H-type and E-type T-junctions.
MAGNETIC FIELDSee H-FIELD.
MAJOR LOBEThe lobe in which the greatest
amount of radiation occurs.
MARCONI ANTENNAA quarter-wave antenna
oriented perpendicular to the earth and operated
with one end grounded.
Also known as
MAXIMUM USABLE FREQUENCYMaximum
frequency that can be used for communications
between two locations for a given time of day
and a given angle of incidence.
MEDIUMThe substance through which a wave
travels from one point to the next. Air, water,
wood, etc., are examples of a medium.
METALLIC INSULATORA shorted quarter-wave
section of transmission line.
MICROWAVE REGIONThe portion of the
electromagnetic spectrum from 1,000 megahertz
to 100,000 megahertz.
MINOR LOBEThe lobe in which the radiation
intensity is less than a major lobe.
MULTIELEMENT ARRAYAn array consisting
of one or more arrays and classified as to
MULTIELEMENT PARASITIC ARRAYAn array
that contains two or more parasitic elements and
a driven element.
MULTIPATHThe multiple paths a radio wave may
follow between transmitter and receiver.
NEGATIVE ALTERNATIONThe portion of a
sine wave below the reference line.
NODEThe fixed minimum points of voltage or
current on a standing wave or antenna.
NONRESONANT LINEA transmission line that
has no standing waves of current or voltage.
NORMALThe imaginary line perpendicular to the
point at which the incident wave strikes the
reflecting surface. Also called the perpendicular.
NULLOn a polar-coordinate graph, the area that
represents minimum or 0 radiation.
OMNIDIRECTIONALTransmitting in all direc-
tions. Also known as NONDIRECTIONAL.
OPEN-ENDED LINEA transmission line that has
an infinitely large terminating impedance.
OPTIMUM WORKING FREQUENCYThe most
practical operating frequency that can be used
with the least amount of problems; roughly 85
percent of the maximum usable frequency.
ORIGINThe point on a graph where the vertical
and horizontal axes cross each other.
OUTPUT ENDThe end of a transmission line that
is opposite the source. Also known as RECEIV-
OUTPUT IMPEDANCEThe impedance presented
to the load by the transmission line and its source.
PARALLEL RESONANT CIRCUITA circuit that
acts as a high impedance at resonance.
PARALLEL-WIREA type of transmission line
consisting of two parallel wires.
PARASITIC ARRAYAn array that has one or
more parasitic elements.
PARASITIC ELEMENTThe passive element of
an antenna array that is connected to neither the
transmission line nor the driven element.
PERIODThe amount of time required for comple-
tion of one full cycle.