What is polarization and why does it matter for antenna alignment?

• A. Polarization is the orientation of the electric field; matching polarization maximizes received power and reduces losses
• B. Polarization is the color of the antenna
• C. Polarization is the phase alignment of the carrier
• D. Polarization is the frequency stability of the oscillator

Answer: (A)

Polarization is the orientation of the electric field of the radio wave as it travels. When the transmitting and receiving antennas share the same polarization—both vertical, both horizontal, or another matching orientation—the field couples efficiently into the antenna, giving maximum received power and minimizing losses. If the receiving antenna is rotated so its polarization is misaligned with the incoming wave, the effective field that the antenna “sees” is reduced, leading to a polarization mismatch loss. For a linear polarization, the received power follows the cos² of the misalignment angle: at 0 degrees you get full power, at 90 degrees you get essentially none, and at 45 degrees you’re down about 3 dB. This is why keeping the antennas aligned in polarization is crucial for a strong, reliable link.

The other options miss the point: the color of the antenna has no impact on signal coupling, the phase alignment of the carrier relates to phase coherence rather than how the electric field is oriented in space, and the frequency stability of the oscillator affects frequency accuracy, not how well the transmitting and receiving fields align with each other.