BasicB-006-012-005

Ignoring ground effects, what is the radiation pattern of a horizontal half-wave dipole installed with the ends pointing North/South?

B
Answer
Antennas and feed lines
Type
A
Radiates equally in all directions
B
Radiates mostly to the East and West
C
Radiates mostly to the South and North
D
Radiates mostly to the South

Answer Notes

A horizontal half-wave dipole radiates energy perpendicular, or broadside, to the axis of the antenna wire. When viewed from above, its radiation pattern resembles a figure-eight. Since the physical ends of this antenna are pointing North and South, the broadside directions are East and West. Little to no RF energy is radiated off the ends of the wire, meaning there is a deep null to the North and South. Options suggesting the antenna radiates equally in all directions describe an isotropic radiator or a vertical dipole. Options pointing North or South mistakenly assume the signal shoots out of the ends of the wire, which is the exact opposite of how a dipole operates.
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