What is dBm?

Raytac Corporation

A BT4.1 & BT4.2 module maker based on Nordic nRF51 & nRF52 solution 

(nRF51822 & nRF51422 & nRF52832 & nRF51802)

Tel: +886.2.3234.0208

What is dBM?

From Spec sheet, we can find the output power always stated as dBM.

For example:

Nordic nRF52832

Transmitting power (+4dBM~-20dBM) / Receiving Sensitivity (-96dBM)

dBm is the unit for radiowave, it is a way to express the comparison between the reference signal value

The reference value is 0dBM at 1mW, the unit represented as shown below

1/10000 times = -40 dBm

1/1000 times = -30 dBm

1/100 times = -20 dBm

1/10 times = -10 dBm

1mW =     0 dbm ← Reference Signal Value

10 times  =  10 dBm

100 times  =  20 dBm

1000 times  =  30 dBm