what does dBm mean
dBm (sometimes dBmW or decibel-milliwatts) is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW). 3 dB increase in level is approximately equivalent to doubling the power, which means that a level of 3 dBm corresponds roughly to a power of 2 mW. For each 3 dB decrease in level, the power is reduced by about one half, making â3 dBm correspond to a power of about 0.5 mW.