Technician: Parallel Dipole

Which of the following describes a simple dipole mounted so the conductor is parallel to the Earth’s surface? [T9A03]

A. A ground wave antenna
B. A horizontally polarized antenna
C. A rhombic antenna
D. A vertically polarized antenna

Lets recall what we mean when we talk about an electromagnetic field being “polarized.”  The direction of polarization means the orientation of the electric field component of the wave.  We can also remember that the electric field component of a signal given off of an antenna such as a wire dipole is polarized in the direction of the wire.  A vertical antenna produces a vertically polarized signal, and a horizontal antenna produces a horizontally polarized signal.  If our dipole is parallel to the Earth’s surface, its horizontal.

Therefore, the answer is B. A horizontally polarized antenna.

It should be noted that the above logic is only a general approximation.  There are plenty of factors which can change a signal’s polarization, but as an estimation, it works.

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