RFID Journal Glossary of Terms
Antenna gain:
In technical terms, the gain is the ratio of the power required at the input of a loss-free reference
antenna to the power supplied to the input of the given antenna to produce, in a given direction, the same field strength at the same distance. Antenna gain is usually expressed in decibels and the higher the gain the more powerful the energy output. Antennas with higher gain will be able to
read tags from farther away.