Decibel

What is Decibel?

The decibel express the ratio between to values with the same unit.

decibel is used in many different fields including science engineering and wireless networks. It measures different ratio such as acoustics , power and sound intensity . The decibel is often comes with a suffix indicating which reference quantity has been used. for example in our decibel interactive tutorial we use dBm to indicate that the reference quantity is one milliwatt.

Power

When measuring power the ratio can be expressed in decibles. It is very common to see it with wireless products. the forumla is:

When P1=P0 in the above equation then LdB = 0. if p1 is greater than P0 then LdB is positive; if p1 is less than P0 then ldB is negative. P0 is the reference value which is equal to one milliwatt (mW).
Simulation

Drag the power slider to show how the dBm level is changing .