Patent ID: 11916542
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. An acoustic wave filter device comprising:
a first terminal;
a second terminal;
an inductor connected to the first terminal; and
a longitudinally coupled resonator coupled between the inductor and the second terminal; wherein
the longitudinally coupled resonator includes:
at least one first IDT electrode coupled to the first terminal; and
at least one second IDT electrode connected to the second terminal;

a total area of an intersecting region of electrode fingers of the at least one first IDT electrode is larger than a total area of an intersecting region of electrode fingers of the at least one second IDT electrode;
each IDT electrode of the at least one first IDT electrode includes a first region in which electrode fingers are provided with a first pitch therebetween and a second region in which electrode fingers are provided with a second pitch therebetween, which is shorter than the first pitch;
each IDT electrode of the at least one second IDT electrode includes a third region in which electrode fingers are provided with a third pitch therebetween and a fourth region in which electrode fingers are provided with a fourth pitch therebetween, which is shorter than the third pitch;
the second region faces the fourth region; and
a number of electrode fingers adjacent to each other with the second pitch therebetween in the second region is greater than a number of electrode fingers adjacent to each other with the fourth pitch therebetween in the fourth region.