DBm

dBm is an abbreviation for the dB referenced to one milliwatt.

Note 1: dBm is used in communication work as a measure of absolute power values. Zero dBm equals one milliwatt. A 3 dBm increase represents roughly doubling the power, which means that 3 dBm equals 2 milliwatt. For a 3 dBm decrease the power is reduced by one half, making -3 dBm equal to 0.5 milliwatt. To express an arbitrary power as , or go in the other direction, the equations and , respectively, should be used. Below is table summarizing useful cases:

Note 2: In DOD practice, unweighted measurement is normally understood, applicable to a certain bandwidth, which must be stated or implied.

Note 3: In European practice, psophometric weighting may be implied, as indicated by context; equivalent to dBm0p, which is preferred.

See also

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