| 摘要 |
<p>An elastic wave filter of a resonator type includes at least one IDT electrode arranged so as to contact the piezoelectric substance. The elastic wave filter is arranged such that an elastic wave in a main propagation mode for obtaining target frequency characteristics and an elastic wave in a sub-propagation mode propagate, the elastic wave being capable of propagating simultaneously with the elastic wave in the main propagation mode, an electromechanical coefficient K2 of the elastic wave in the sub-propagation mode is in the range from about 0.1% to about one third of an electromechanical coefficient K2 of the elastic wave in the main propagation mode, and a sound velocity of the elastic wave in the sub-propagation mode differs from a sound velocity of the elastic wave in the main propagation mode.</p> |
