The antenna that serves as a reference for comparing the gain of other antennas is called a:

The antenna that serves as a reference for comparing the gain of other antennas is the dipole antenna. This is because a dipole antenna is widely used as the standard reference in antenna theory due to its simple structure and predictable radiation pattern. It typically has a gain of 2.15 dBi, which means it provides a baseline for measuring and expressing the performance of other antennas in terms of gain.

The dipole's balanced characteristics allow for effective horizontal or vertical polarization, making it a versatile option in many applications. This reference point is crucial in the field of telecommunications and broadcast, as it allows engineers and technicians to evaluate how well other antenna designs perform in comparison to the dipole's established baseline.

While monopole, loop, and Yagi antennas have their own specific applications and advantages, they do not serve as the standard reference for gain comparison in the same way that the dipole does.