11.
The receiving antenna will absorb maximum energy when the transmitting
and receiving antennas are polarized identically.
A horizontally
polarized antenna is physically positioned
a.
perpendicularly to the earth, and its electric field will be
perpendicular to the earth.
b.
perpendicularly to the earth, and its electric field will be
parallel to the earth.
c.
parallel to the earth, and
its
electric
field
will
be
perpendicular to the earth.
d.
parallel to the earth, and its electric field will be parallel to
the earth.
12.
A radar antenna system consists of a feed system and a reflector.
The
reflector is used to
a.
permit the
use
of
one
antenna
for
both
transmitting
and
receiving.
b.
change the polarization of the transmitted wave.
c.
allow the antenna to radiate in all directions.
d.
make the antenna directional.
13.
Assume that the radar antenna shown in Figure 131 has a gain of 2,000.
This gain of 2,000 means that the radar antenna
a.
amplifies the RF power 2,000 times.
b.
absorbs 20 percent of the RF power.
c.
absorbs 2,000 times more power than a simple dipole.
d.
radiates 2,000 times more power than a simple dipole.
14.
A radar antenna consists of a feed and a reflector. The type of feed
that employs a resonant cavity to couple the RF energy to the
reflector is a
a.
horn feed system.
b.
dipole feed system.
c.
cutler feed system.
d.
linear array of dipoles.
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