Impedance

Tuned Circuit & Filter Bandwidth

  • Either side of resonance the response falls off.  When the response in voltage terms reaches 0.707 (√ ½) of the value at resonance, this range of frequencies is known as the (half power) bandwidth or -3dB bandwidth
  • For filters another important parameter can be shape factor which is the ratio of (-)6/60dB bandwidth; less than 2:1 is acceptable