What is the name of the antenna used to compare the gain of other antennas?

The antenna used to compare the gain of other antennas is known as the dipole antenna. This is largely due to its well-defined radiation pattern and consistent gain characteristics across various frequencies, making it an ideal reference point. A dipole antenna is typically designed as a half-wavelength section of wire and radiates energy efficiently in a figure-eight pattern. This property allows it to serve as a standard or benchmark against which other antennas can be measured.

Other antenna types, while useful for various specific applications, do not possess the same level of standardization and predictable gain that dipoles do. Monopole antennas can be effective but are generally used in different scenarios and are not as versatile for comparative analysis. Yagi antennas, which consist of multiple elements, are highly directional and designed for specific gain rather than serving as a baseline. Parabolic antennas are typically associated with focusing signals and achieving high gain in one direction, primarily used in satellite communications, but do not provide the standardized gain characteristics needed for broad comparative analysis.

Because of these characteristics, the dipole antenna is the preferred choice for establishing a reference point in antenna gain comparisons.