ELASTIC WAVE RESONATOR, ELASTIC WAVE FILTER DEVICE, AND DUPLEXER

摘要

An elastic wave includes a piezoelectric substrate having a polarization direction denoted by an arrow Px, and first and second IDT electrodes arranged on the substrate in an elastic wave propagation direction with a shared reflector therebetween. A first bus bar of the first IDT electrode and a first end portion bus bar of a second reflector are connected to a wiring electrode to define a first terminal. A second bus bar of the first IDT electrode and a second end portion bus bar of the shared reflector are connected to each other to define a second terminal. A first end portion bus bar and a first bus bar are electrically connected to each other. A second bus bar and a second end portion bus bar are electrically connected to each other, and the first and second IDT electrodes and are connected in parallel between the first and second terminals.

主权项

1. An elastic wave resonator comprising:
a first terminal; a second terminal; a piezoelectric substrate having a polarization direction; first and second IDT electrodes extending in an elastic wave propagation direction on the piezoelectric substrate; a shared reflector located between the first IDT electrode and the second IDT electrode; a first reflector located opposite to the shared reflector with the first IDT electrode therebetween; and a second reflector located opposite to the shared reflector with the second IDT electrode therebetween; wherein a projected polarization direction is perpendicular or substantially perpendicular to the elastic wave propagation direction, the projected polarization direction being a direction obtained by projecting the polarization direction onto a substrate surface of the piezoelectric substrate; assuming that a leading end side in the projected polarization direction is a first end portion side, and a base end side in the projected polarization direction is a second end portion side, the elastic wave resonator further comprises a wiring electrode electrically connecting respective first-end-portion-side portions of the first reflector, the first IDT electrode, and the second reflector to one another, the wiring electrode defining the first terminal; respective second-end-portion-side portions of the first IDT electrode and the shared reflector are electrically connected to each other and define the second terminal; respective first-end-portion-side portions of the shared reflector and the second IDT electrode are electrically connected to each other; respective second-end-portion-side portions of the second IDT electrode and the second reflector are electrically connected to each other; and the first and second IDT electrodes are connected in parallel between the first terminal and the second terminal.