| 摘要 |
A dual-mode acoustic wave resonator ( 7 a) having a resonance mode inter-coupler ( 6 ) is disposed across narrow voids ( 4, 5 ) from an input electrode ( 2 ) and an output electrode ( 3 ). They are supported for vibrations on a substrate by conductive posts ( 27, 28, 29 ) and a power supply pad ( 3 ). Opposing electrodes ( 10, 11, 21, 23 ) are formed below the input and output electrodes ( 2, 3 ), resonator ( 7 a), and resonance mode inter-coupler ( 6 ) across narrow gaps. As a voltage of a power supply ( 25 ) is changed, a distortion of the resonator ( 7 a) changes due to an electrostatic force, causing a change in the center resonance frequency. As voltages of power supplies ( 16, 17 ) are changed, distortions of the input and output electrodes ( 2, 3 ) change to cause a change in the opposing areas of end faces of the input and output electrodes to the resonator ( 7 a). This causes a change in the situation of exchanging energy between the input and output electrodes and the resonator ( 7 a) to change the external Q-value. As the voltage of the power supply ( 25 ) is changed, a distortion of the inter-coupler ( 6 ) changes to cause a change in the coupling coefficient between the resonance modes.
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