710 B
710 B
Gain, Decibels, and Loss
- Calculate decibel and numerical gain
- describe decibel, and compute
- State the gain and loss numerically
Systems have a large range of levels. Transmitters output 100W, while recievers use 10^{-15}W. Within a tranciever, it can be micro to femto volts.
Decibel calculation:
P_{dB}=10log_{10}(\frac {P_1} {P_2} )
Voltage decibels use 20log instead of 10log.
Gain calculation:
A=\frac {P_{out}}{P_{in}}
gain can also be done in decibels
if (numerical gain > 1) gain=gain;
else gain=loss;
cascaded gain, multiply gains
cascaded decibel gain, add them
numerical gain > 1 == decibel gain > 0
numerical gain < 1 == decibel gain < 0
dBmV
dBuV