| 摘要 |
There is disclosed an acoustic transducer (20) for communications within an operational bandwidth, the transducer comprising:
A signal generator (22) for generating a signal at a centre-frequency within the operational bandwidth;
A piezoelectric element (13) having a dielectric constant that varies with temperature;
A driving electrode (12) at the surface of the piezoelectric element (13);
A matching network (21), having a natural frequency at a given temperature, and operable to transfer the signal from the signal generator (22) to the piezoelectric element (13) whilst mitigating electrical loss, the matching network (21) being connected to the driving electrode (12); Wherein the matching network (21) comprises a temperature compensating capacitor (28) connected in parallel with the piezoelectric element (13), the temperature compensating capacitor (28) being for counteracting temperature-induced changes to the dielectric constant of the piezoelectric element (13) such that the electrical natural frequency of the transducer (20) is substantially constant over a range of temperatures. |
