Multimode elastic wave device
AssigneeSkyworks Filter Solutions Japan Co., Ltd.
InventorsTomoya Komatsu, Joji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura, Kazunori Nishimura
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Abstract
A multimode elastic wave device includes a pair of reflectors, and a first interdigital transducer (IDT) electrode through a fifth IDT electrode arranged between the pair of reflectors. In this configuration, each of the average of electrode-finger pitches in the first IDT electrode and the average of electrode-finger pitches in the fifth IDT electrode is smaller than both of the average of electrode-finger pitches in the second IDT electrode and the average of electrode-finger pitches in the fourth IDT electrode.
Claims17
A multimode elastic wave device comprising:
- a piezoelectric substrate;
- a first reflector and a second reflector disposed on the piezoelectric substrate;
- and
- a first interdigital transducer (IDT) electrode, a second IDT electrode, a third IDT electrode, a fourth IDT electrode, and a fifth IDT electrode disposed in ordinal order on the piezoelectric substrate between the first reflector and the second reflector along a propagation direction of elastic waves in the multimode elastic wave device, each of the first IDT electrode through the fifth IDT electrode including electrode fingers and having a constant-pitch region in which an electrode-finger pitch of the electrode fingers is substantially equal, a first average of the electrode-finger pitch in the first IDT electrode and a fifth average of the electrode-finger pitch in the fifth IDT electrode both being smaller than both a second average of the electrode-finger pitch in the second IDT electrode and a fourth average of the electrode-finger pitch in the fourth IDT electrode, and a third average of the electrode-finger pitch in the third IDT electrode being smaller than both the second average of the electrode-finger pitch in the second IDT electrode and the fourth average of the electrode-finger pitch in the fourth IDT electrode, such that the multimode elastic wave device suppresses resonance in high order longitudinal modes in frequencies proximate a low frequency side of a passband of the multimode elastic wave device.
A multimode elastic wave device comprising:
- a piezoelectric substrate;
- a first reflector and a second reflector disposed on the piezoelectric substrate;
- and
- a first IDT electrode, a second IDT electrode, a third IDT electrode, a fourth IDT electrode, and a fifth IDT electrode disposed in ordinal order on the piezoelectric substrate between the first reflector and the second reflector along a propagation direction of elastic waves in the multimode elastic wave device, each of the first IDT electrode through the fifth IDT electrode, the first reflector, and the second reflector including electrode fingers and having a constant-pitch region in which an electrode-finger pitch of the electrode fingers is substantially equal, the electrode-finger pitch in the constant-pitch region of each of the first IDT electrode, the third IDT electrode, and the fifth IDT electrode being smaller than both the electrode-finger pitch in the constant-pitch region of the second IDT electrode and the electrode-finger pitch in the constant-pitch region of the fourth IDT electrode, and the electrode-finger pitch in the constant-pitch region of each of the second IDT electrode and the fourth IDT electrode being larger than both the electrode-finger pitch in the constant-pitch region of the first reflector and the electrode-finger pitch in the constant-pitch region of the second reflector, such that the multimode elastic wave device suppresses resonance in high order longitudinal modes in frequencies proximate a low frequency side of a passband of the multimode elastic wave device.
Dependencies are inferred from the claim text.