Question T9A03
From subelement T9 - T9A
Which of the following describes a simple dipole oriented parallel to Earth's surface?
Why is this correct?
A dipole antenna oriented parallel to Earth's surface is horizontally polarized because the antenna's orientation determines its polarization. When the dipole wire runs horizontally (parallel to the ground), the electric field of the radiated waves oscillates horizontally, creating horizontal polarization. Options A and C describe propagation methods, not polarization types. Option D would require the dipole to be oriented vertically (perpendicular to Earth's surface).
Memory tip
Remember: antenna polarization directly matches the antenna's physical orientation. Horizontal antenna = horizontal polarization, vertical antenna = vertical polarization. This principle applies to all linear antennas, making polarization questions straightforward once you visualize the antenna's physical position relative to the ground.
Learn more
Horizontal polarization is commonly used for long-distance VHF and UHF weak-signal communications because it provides better signal characteristics for these frequency privileges. In practical operation, matching polarization between transmitting and receiving antennas maximizes signal strength—mismatched polarization can cause significant signal loss. Understanding polarization helps optimize your station's emission standards and communication effectiveness.
Think about it
Why do you think a horizontally oriented dipole radiates horizontally polarized waves rather than vertically polarized ones?