What Is Antenna Gain and How Does It Affect Your Wi-Fi Signal

An antenna is an electrical device that receives electrical current and converts it into a radio wave, used for transmitting and receiving voice and data. Antennas are made of conductive metals such as gold, silver, copper, aluminum, and steel, typically wrapped in an insulator such as hard rubber or plastic. These materials cannot create power from the current the antenna receives — they can only conduct it. This page defines six key antenna gain terms to help you understand how antennas on your TP-Link device work.

Key Takeaways

• Antennas do not create power. They convert electrical current into radio waves.
• Antenna gain (dBi) measures how efficiently an antenna focuses power in a specific direction relative to a theoretical isotropic antenna.
• The higher the antenna gain, the more directional the signal becomes. An antenna's power doubles for every 3 dBi of gain.
• The radiation pattern shows whether an antenna is directional, bi-directional, or omnidirectional.
• A higher-gain antenna provides greater coverage distance but a narrower beamwidth.

Key Antenna Gain Terms and Definitions

The following terms explain how the antennas on your TP-Link network device work, with antenna gain explained alongside related concepts like radiation pattern and coverage.

Decibel (dB)

This is the unit of measure of loss or gain. This value represents the ratio between two amounts of electrical or acoustical power received. In basic terms, it’s a measurement of power.

Decibel-isotropic (dBi)

This is a hypothetical reference point at which an isotropic antenna transmits a signal uniformly over a perfect sphere. A perfect sphere is impossible to create, so 0 dBi is a theoretical reference point, not an achievable value.

Antenna Gain

Also known simply as "gain," this is a measure of power that represents the efficiency with which an antenna converts electrical power into radio waves. When speaking in terms of antennas:

Gain + dB = dBi of an antenna

The antenna gain dBi value affects the direction in which the antenna operates. The higher the gain, the more directional the antenna becomes. An antenna's power doubles for every 3 dBi. To learn how this affects your signal reach, see how to improve your Wi-Fi signal and wireless range.

Radiation Pattern

This is a graphical representation of the signal emitted from the antenna. In simple terms, it represents whether your Antenna is directional, Bi-directional, or omnidirectional.

Radiation Angle

This is the antenna's beamwidth. It has a horizontal and vertical number in degrees. This number indicates the area of coverage where the radiation pattern is emitting.

For example, if a TP-Link outdoor access point TL-WA7510N has a directional antenna with a horizontal radiation angle of 60 degrees and a vertical radiation angle of 15 degrees, this means the receiver endpoint must be at the same angle to receive a signal. This becomes very important when setting up an extended wireless network.

Coverage

This is the physical area in which a signal can still be received and transmitted. In general, the more powerful an antenna is, the more coverage it provides. However, the more powerful an antenna is, the more directional its signal becomes.

Summary

Antennas do not generate power; they convert it into a usable RF signal. The power or gain determines the general distance and direction the antenna signal will achieve. The higher the power, the narrower the beam width.