What unit of measurement is used to express the gain of an antenna?

What unit of measurement is used to express the gain of an antenna?

• A. Watts (W).
• B. Decibels (dB).
• C. Pascals (Pa).
• D. Ohms (Ω).

Answer: (B)

Gain describes how well an antenna focuses energy in a direction compared to a reference antenna. Because gain is a ratio, expressing it in decibels makes the scale easier to manage and compare across different antennas and frequencies. Antenna gain is usually written as dBi (relative to an isotropic radiator) or dBd (relative to a dipole). The other units listed—watts measure power, pascals measure pressure, ohms measure impedance—refer to absolute quantities, not the directional improvement that gain expresses, so they aren’t used for this purpose.

Gain describes how well an antenna focuses energy in a direction compared to a reference antenna. Because gain is a ratio, expressing it in decibels makes the scale easier to manage and compare across different antennas and frequencies. Antenna gain is usually written as dBi (relative to an isotropic radiator) or dBd (relative to a dipole). The other units listed—watts measure power, pascals measure pressure, ohms measure impedance—refer to absolute quantities, not the directional improvement that gain expresses, so they aren’t used for this purpose.