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.
0.7746 volts, assuming power reference is 1mw into a 600 ohm.
77.45mV
2.45mV
To find the actual voltage level measured, you need to use the formula to convert dBm to voltage level in a 600Ω system.
The formula is as follows:
V = √(10^(dBm/10) × (Z/1000))
Where:
V is the voltage in volts (V)
dBm is the power level in decibels referenced to 1 milliwatt (dBm)
Z is the impedance in ohms (Ω)
Let's plug in the given values into the formula:
dBm = +10dBm
Z = 600Ω
V = √(10^(10/10) × (600/1000))
V = √(10^1 × 0.6)
V = √(10 × 0.6)
V = √6
Therefore, the actual voltage level measured is approximately √6 or around 2.449 Volts.
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.