RFID Journal Glossary of Terms
Decibel:
A unit used to express the ratio between two values, including
antenna gain, cable losses and
reader power output. The formula for decibel is:
dB=10 log (P1/P2). In layman’s terms, dB represents the difference in the intensity of an emitted signal or power where 0 dB is the reference, 3 dB is twice the intensity of 0 dB, 10 dB is 10 times the intensity, and 20 dB is 100 times the intensity and so on. (See also
dBi,
dBm and
dBw.)