Q-factor is Not Q-value. in Q-factor, the Q is for Quality.
Q-factor is a dimensionless factor for showing the degree of reasonace of a coil or an Oscillator.
Higer value means a better coil. The definition is the resonance frequency over the Full Width Half Maximum (FWHM).
High value means:
- high sensitivity
- noise reduction due to narrow band of absorption.
- over damped with long decay time.
- higher energy stored
- lower energy loss
For complex electric circuit, the Q factor is:
Q = | im Z/ re Z|
It seem that there is a conflict between impedance matching.