Antenna Gain
The term *gain* describes an antenna’s ability to concentrate electromagnetic energy in a specific direction.
It does not increase transmitter power, but uses the available RF energy more efficiently.
A low-gain antenna radiates energy over a wide area, while a high-gain antenna focuses the signal into a narrower beam, increasing signal strength in the desired direction.
Practical example using:
4/6/16-element Yagi antennas
4-element Yagi → about 7–8 dBd
Relatively wide beamwidth and good general coverage.
6-element Yagi → about 10 dBd
Greater directivity and improved front-to-back ratio.
16-element Yagi → more than 15 dBd
Very narrow beamwidth, highly concentrated energy, and excellent DX performance
Using the same transmitter power:
* the 4-element Yagi spreads the signal over a wider sector;
* the 16-element Yagi concentrates most of the energy into a very precise direction.
The result is a much stronger perceived signal in the aimed direction, without any real increase in transmitted power.
