RF Units

Decibel Conversion: Power
dB = 10 log [P2/P1]
Decibels relative to Power

Decibel Conversion: Voltage
dB = 20 log [V1/V2]
Decibels relative to Voltage across same resistance

Decibel Conversion: Milliwatts
dBm = 10 log [Power of signal Signal (W)/1mW]
Decibels relative to one milliwatt (R needs to be specified; often 50 or 75 ohm)

Decibel Conversion: Microvolts
mV = 20 log [Signal (V) /1mV]

Decibels relative to one microvolt across same resistance

dBc = dB referenced to a carrier (voltage or power)


Useful LOG manipulation formulas:

 Useful log relations5