dBm is a value that represents the absolute value of power (which can also be considered as a ratio based on a power of 1 mW), calculated as 10 log (power value / 1 mw). Here we introduce a method of calculating dBm to W, which is summarized as "1 benchmark" and "2 principles":

1基准:

30dBm＝1W

2 principles:

Principle one:

+ 3dB, power by 2 times; -3dB, power by 1/2

Example:

33dBm＝30dBm+3dBm＝1W×2=2W

27dBm＝30dBm－3dBm＝1W×1/2=0.5W

Principle two:

+ 10dBm, power by 10 times; -10dBm, power by 1/10

Example:

40dBm＝30dBm+10dBm＝1W×10=10W

20dBm＝30dBm－10dBm＝1W×0.1=0.1W

The above can be simply recorded as: 30 is the benchmark, equal to 1W whole, swap is not difficult, the most simple port count. Add 3 times 2, plus 10 times 10; subtract 3 from 2, minus 10 to 10.

The dBm for almost any integer can be converted to W with "1 benchmark" and "2 principles" above.

example 1:

44dBm=?W

44dBm=30dBm+10dBm+10dBm－3dBm－3dBm 　　

=1W×10×10×1/2×1/2 =25W

example 2:

32dBm=?W

32dBm=30dBm+3dBm+3dBm+3dBm+3dBm－10dBm

　　 =1W×2×2×2×2×0.1=1.6W

Calculation skills:

+ 1dBm and + 2dBm calculation skills

+1dBm=+10dBm－3dBm－3dBm－3dBm

=X×10×1/2×1/2×1/2

=X×1.25

+2dBm=－10dBm+3dBm+3dBm+3dBm+3dBm

=X×0.1×2×2×2×2=X×1.6w

In the calculation, sometimes according to the above rules can be transformed into -1dBm and -2dBm, to achieve the purpose of rapid mouth speed, namely:

－1dBm=－10dBm+3dBm+3dBm+3dBm

=X×0.1×2×2×2

=X×0.8

－2dBm=－3dBm+1dBm

=X×1/2×1.25

=X×0.625

example 3：

51dBm=30dBm+10dBm+10dBm+1dBm

=1W×10×10×1.25