dBd is decibel above the gain of a dipole antenna as a reference.

A dipole antenna is know to have a gain of 2.15 dBi. But as the isotrope antenna is a mathematical antenna technicians generally use the dipole antenna as a reference.

• In the case of a yagi antenna with a gain of 14 dBd the yagi has 14 dB more gain as a dipole.

Calculate from and to other units ? Use the 'On-line RF calculator'.