APPENDIX 
241 
Quality factor (Q) and Dissipation factor (D) 
 
The quality factor measures energies consumed by relative 
frequency. In general, the better a circuit's quality factor the better 
its selectivity. 
The dissipation factor is the reciprocal of quality factor. It is the 
signal angle loss by a capacitor (or inductor) and acting frequency 
at a fixed temperature. Phase shifts caused by time lag between an 
externally applied voltage and current generated may result in loss 
of current and energy dissipation. Here the total current (I) is the 
sum of the charging current (Ic) by a 90 ゚ voltage phase shift and 
loss current (IR) of the same voltage. The loss angle is the angle δ 
between the total current and charging current and tanδ the 
dissipation factor (symbol: D) as shown in the figure below: