Читать книгу Lead-Free Piezoelectric Materials - Jing-Feng Li - Страница 19
1.4.3 Mechanical Quality Factor
ОглавлениеThe mechanical Q (also referred to as Q) is the ratio of the reactance to the resistance in the series equivalent circuit representing the piezoelectric resonator, which is related to the sharpness of the resonance frequency. The mechanical QM can be calculated using the equation:
(1.15)
where fr is the resonance frequency, f1 and f2 are frequencies at −3 dB of the maximum admittance. The mechanical QM is also related to the electromechanical coupling factor k, following the equation:
(1.16)
where
| F r | Resonance frequency (Hz) |
| F a | Anti‐resonance frequency (Hz) |
| Z m | Impedance at Fr (ohm) |
| C 0 | Static capacitance (Farad) |
