¥In signal
analysis we frequently want to compare the power of two signals.
¥The decibel (dB) provides a
convenient way to measure the difference of two power levels.
¥It measures the
logarithmic power difference between two signals.
¥If a signal is
attenuated by 2 dB in one stage of transmission, then is attenuated by 5 dB in the next
stage of transmission, we the two decibel measurements to find the total
attenuation of the two stages, in this case 7 dB.
¥Signal power equals to waveform power
– DC power