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# Decibel (dB): What is dB, dBm, dBW, and dBV in Electronics? Difference between dB and dBm

In this video, the Decibel (dB) scale which is commonly used in electronics and communication system is discussed.

In this video, you will also learn about the different decibel scales like dB, dBm, dBW, and dBV, and how to convert dBm to dBW and dBw to dBm.

What is decibel (dB):
The decibel is logarithmic scale which defines the ration of two quantities.
In electronic circuits and system, it is commonly used to define the power or voltage gain of the amplifier or system.

When it is used to define power or power gain, then it is represented as
Gain in dB= 10 log (Gain)

And when it used to define the voltage or voltage gain, it is represented as
Gain in dB = 20 log (Gain)

What is dBm, dBW, and dBV

This decibel scale can also be used to represent voltage and power.
But as decibel scale is unitless, so this power and voltage can be represented with respect to some reference power or voltage.

dBW: When power is represented with respect to 1W of power in decibel scale then it is represented as dBW.

dBV: When the voltage is represented with respect to 1V of voltage in decibel scale then it is represented as dBV.

dBm: when power is represented with respect to 1 mW of power in decibel scale then it is represented as dBm.

Time stamps for the different topics covered in the video:

0:56 Decibel (dB) in electronics
2:15 Representation of Power Gain in dB
6:26 Representation of Voltage Gain in dB
8:40 What is dBW, dBm, and dBV?
11:40 dBm to dBW and dBW to dBm conversion

This video will be helpful to all student of science and engineering in understanding the different decibel scales.