This tool converts transmitter output power in Watt and Antenna gain in dBi to Effective Isotropic Radiated Power (EIRP)
An antenna’s dBi value is a measure of its gain compared to a reference antenna. The reference antenna is isotropic, which means that it emits signal equally in all directions. An antenna with a higher dBi value has more gain than an antenna with a lower dBi value.
dB values are always relative to something else – in this case, relative to an isotropic antenna.
When choosing an antenna for a particular application, it is important to consider its gain. A directional antenna with high gain can be a good choice for applications where you need to maximize the signal strength in a specific direction, such as when aiming a radio signal at a specific target. However, directional antennas can also make it more difficult to receive signals from other directions, so they are not always the best choice for every application.