09. From Frequency Response to Bode Plot
The decibel is introduced as ten times the logarithm of a power ratio. Some possible motivations for using decibels are presented. The reason that a factor of twenty multiplies the decibel gain for voltage and current gains is explained. The magnitude and phase plot of a low-pass filter are briefly explained. The decibel plot of the magnitude is given. Then the method for drawing a first-order Bode plot of the magnitude and phase is presented.
