Converting d Bm signal in Watts using the rule of 10 's and 3 's without using the calculator For example: If we have the transmitter output signal strength of 26dBm and we want to know the absolute power value in Watts. Here how we do; we break down the 26dbm like this; 26dbm=10dbm+10dbm+3dbm+3dbm; Given that 0dBm=1mW - Adding 10db makes the signal power of 10mw or 1mw10. - Adding another 10db makes the signal power of 10mw or 1mw10. - Adding 3db multiply the signal power by 2 , making it 200mw - Adding another 3db multiply the signal power by 2 (or doubles) makes the signal power of 400mw therefore 26dBm=400mW What happened if we feed the 400mW through the amplifier circuit below? Show output in mw and dtm Guide to Wireless Communications, Fourth Edition (- Cengage Learning 2