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Decibel (dB) and dB relative to a milliwatt (dBm)
dB and dBm are both units of measurement used to express the power of a signal, but they are based on different reference points.
dB is admentional unit used to make a comparison between 2 levels of power, voltage or current dB=10 log (Pa/Pb).
dBm is a unit of any level of power referred to 1mW, in another word: dBm = 10log (P(mW)/1 mW)
It is used forquantifying the ratio between two values. The best example of this is the signal-to-noise ratio.
0dB= 30dbm
dB is the unit of power in Watt
dBm is the unit of power in mWatt
dB vs. dBm. Decibel (dB) and dB relative to a milliwatt (dBm) represent two different but related concepts.The unit dBm denotes an absolute power level measured in decibels and referenced to 1 milliwatt (mW).
Whenever tests are performed on fiber optic networks, the results are displayed on a meter readout in “dB.” Optical loss is measured in “dB” while optical power is measured in “dBm.” Loss is a negative number (like –3.2 dB) as are most power measurements.
db and dbm r differnt but they r relative.db is the ratio of two values.dbm is the absolute power level in db's in milliwatt
Decibel (dB) and dB relative to a milliwatt (dBm) represent two different but related concepts. A dB is a shorthand way to express the ratio of two values. ... The unit dBm denotes an absolute power level measured in decibels and referenced to 1 milliwatt (mW)
Decibel (dB) and dB relative to a milliwatt (dBm)
dBm value=(dB value+)
because dBm is reference to milli
dB is a measurement unit to quote the signal strength of a strong signal where dBm is a smaller unit , usually used with the prefix milli
