Specifications

5-11
Figure 5-14. Test fixture effects
Q measurement accuracy
Generally, the Q-factor measurement accuracy in the impedance measurement is not high enough to
measure the high Q device. Figure 5-15 shows the relationship of Q accuracy and measured Q val-
ues. Because the Q value is the reciprocal of D, (Q = 1/D), the Q accuracy is related to the specified
D measurement accuracy as shown in Figure 5-15. The Q measurement error increases with the
DUT’s Q value and, therefore, the practically measurable Q range is limited by the allowable Q mea-
surement error. (For example, if the allowable Q error is ten percent and if the instrument’s D accu-
racy is ±0.001, the maximum measurable Q value is 90.9. (See Appendix E for the Q measurement
accuracy calculation equation.)
Figure 5-15. Q measurement accuracy