5) A microwave transmitter typically requires a +8dBm audio level to drive the input fully. If a +10dBm level is measured, what is the actual voltage level measured? Assume a 600Ω system.
4 answers
0.7746 volts, assuming power reference is 1mw into a 600 ohm.
dbm = 10*Log(Po/Pi) = 10.
10*Log(Po/1) = 10.
Log(Po/1) = 1.0.
Po/1 = 10^1 = 10.
Po = 10 mW = Power output of driver to transmitter.
Po = Vo^2/R = 10 mW = 0.01 W.
Vo^2/600 = 0.01
Vo^2 = 6.
Vo = 2.45 Volts across 600 Ohms.
10*Log(Po/1) = 10.
Log(Po/1) = 1.0.
Po/1 = 10^1 = 10.
Po = 10 mW = Power output of driver to transmitter.
Po = Vo^2/R = 10 mW = 0.01 W.
Vo^2/600 = 0.01
Vo^2 = 6.
Vo = 2.45 Volts across 600 Ohms.
77.45mV
2.45mV