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> when I think they mean dBmw (an absolute measurement).

I think you may mean dBm or dBmW here. 0dBm == 1mW.

The SI symbol for Watt is ‘W’ not ‘w’.

At 2.4GHz, free space path loss is -41dB at 1m, so even a 20dBm radio and a 20dBi directional antenna (and assuming 0dB of insertion loss), the signal strength at 1m is -1dBm, or about 0.79 mW.

At 3m, the free space path loss is nearly -50dB. Now the signal from the setup above is at -10dBm, or 0.1mW.

https://ecfsapi.fcc.gov/file/10417871820142/2018%2BRF%2BRadi...



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