Question T9A11
From subelement T9 - T9A
What is antenna gain?
Why is this correct?
Antenna gain (C) is the increase in signal strength in a specified direction compared to a reference antenna, not additional power from the transmitter (A), power requirements (B), or impedance changes (D). Think of gain like a spotlight versus a regular bulb - you get brighter light in one direction by redirecting existing light, not adding more power. Gain redistributes the signal pattern to concentrate energy where you want it.
Memory tip
Look for 'compared to a reference' language in gain questions - this signals measurement relative to a standard (like dBi or dBd), not absolute increases. Gain is always about signal redistribution and directional comparison, never about adding power or changing electrical properties like impedance.
Learn more
In practical operation, antenna gain helps overcome path loss on weak signal bands like 6 meters and above. Higher gain antennas like Yagis concentrate your emission pattern toward distant stations while reducing interference in unwanted directions. This directional focusing is especially valuable for DXing and weak signal work, where every dB of effective radiated power matters for successful communication.
Think about it
Why do you think antenna manufacturers specify gain in dBi (compared to an isotropic radiator) rather than just stating how much stronger the signal gets?