chapter  35

Q Factor Measurement

WithAlbert D. Helfrick

Q factor is a method of characterizing the rate of dissipation of energy from an oscillating system [1]. Q is defined as 2π times the energy stored in a resonant system divided by the energy dissipated per cycle. The term system used in this context refers to any type of resonance: mechanical, electric, nuclear, etc. For the purposes of this handbook, Q will be that of an electric circuit. Also, for the discussion of Q, very low values of Q, typically less than 10, will not be considered as these low values of Q produce highly damped oscillations that are more exponential than oscillatory and the concept of Q does not fit.