What is antenna gain?

Antenna gain refers to the increase in signal strength in a specified direction compared to a reference antenna. This concept is central to antenna design and performance, as it quantifies how effectively an antenna converts input power into radio waves in a focused direction, rather than distributing that power equally in all directions.

When discussing gain, it's important to note that it is often measured relative to a standard reference antenna, such as an isotropic radiator, which radiates energy uniformly in all directions. High gain antennas are designed to focus energy in a specific direction, which enhances the signal strength over that direction, making them more effective for communication and reducing signal loss in sending and receiving information.

Additionally, understanding antenna gain is crucial for various applications in amateur radio, allowing operators to select the right antennas for their intended communications, whether aiming for long-distance contacts or enhancing reception in specific areas.