Gain of an antenna is measured in which unit?

Gain of an antenna is measured in which unit?

• A. Watts
• B. dB
• C. Hertz
• D. Ohms

Answer: (B)

Antenna gain describes how much power the antenna concentrates in a particular direction compared with a reference antenna. Because it’s a ratio, it’s expressed in decibels (dB), which is a logarithmic way to compare two quantities. In practice you’ll see gain given as dBi (gain over an isotropic radiator) or dBd (gain over a half-wave dipole). This is why dB is the correct unit: it reflects the relative, directional performance rather than an absolute quantity like power, frequency, or resistance. For contrast, watts measure power, hertz measure frequency, and ohms measure impedance—none of those capture the directional amplification that gain represents. For example, if the main lobe delivers ten times more power than the reference, the gain in linear terms is 10, which corresponds to 10 dB.

Antenna gain describes how much power the antenna concentrates in a particular direction compared with a reference antenna. Because it’s a ratio, it’s expressed in decibels (dB), which is a logarithmic way to compare two quantities. In practice you’ll see gain given as dBi (gain over an isotropic radiator) or dBd (gain over a half-wave dipole). This is why dB is the correct unit: it reflects the relative, directional performance rather than an absolute quantity like power, frequency, or resistance. For contrast, watts measure power, hertz measure frequency, and ohms measure impedance—none of those capture the directional amplification that gain represents. For example, if the main lobe delivers ten times more power than the reference, the gain in linear terms is 10, which corresponds to 10 dB.