Miscellaneous

deciBels

  • A logarithmic unit the deciBel (dB) is often used to express the ratio of output to input signal levels
    • 0dB means zero power gain
    • 3dB means a doubling of power
    • 6dB : 4 times
    • 10dB : 10 times
    • 20dB : 100 times
    •  
    • -3dB : ½
    • -6dB : ¼
    • -10dB : 1/10
    • -20dB : 1/100
  • When amplifiers and or attenuators are connected in series the overall gain in dB is calculated by adding (or subtracting) the individual dB gains