Quality Factor
- The quality factor defines the sharpness of resonance.
- It is defined as:
- where
- Q = quality factor
- ω0 = resonance frequency [rads-1]
- ω1 = is the frequency below resonance for which the average power has dropped to half that at resonance [rads-1]
- ω2 = is the frequency above resonance for which the average power has dropped to half that at resonance [rads-1]
- ω0 = resonance frequency [rads-1]
- It is an inherent characteristic of an oscillator that influences its stability. Generally speaking, the higher the Q, the more stable the oscillator, since a high Q means that an oscillator will stay close to its natural resonance frequency.
- Examples
Oscillator Type Quality Factor, Q Tuning Fork 103 Quartz Wristwatch 104 Oven Controlled Crystal Oscillator 106 Rubidium 107 Caesium Beam 108 Hydrogen Maser 109 Caesium Fountain 1010 Mercury Ion Optical Standard 1014 - It is an inherent characteristic of an oscillator that influences its stability. Generally speaking, the higher the Q, the more stable the oscillator, since a high Q means that an oscillator will stay close to its natural resonance frequency.
In a reactive circuit, the quality factor is the ratio of the reactance in ohms divided by the resistance in ohms.
See also: Resonance.
Subjects: Electronics Noise & Vibration Physics