Patent classifications
H03H9/14588
ELASTIC WAVE DEVICE AND MANUFACTURING METHOD FOR SAME
An elastic wave device includes an IDT electrode on a piezoelectric substrate to define a longitudinally coupled resonator elastic wave filter, a three-dimensional wiring portion on the piezoelectric substrate and connected to the longitudinally coupled resonator elastic wave filter, and a cover surrounding the longitudinally coupled resonator elastic wave filter on the piezoelectric substrate. The three-dimensional wiring portion includes a lower layer wiring line, an upper layer wiring line, and an insulating layer stacked between the lower layer wiring line and the upper layer wiring line. The cover includes a portion on the three-dimensional wiring portion.
Ladder-type elastic wave filter having series and parallel resonators
A ladder-type elastic wave filter includes an input terminal, an output terminal, and a ground terminal, a first series resonator and a second series resonator connected in series between the input terminal and the output terminal, and a first parallel resonator having a first terminal electrically connected to the series connection between the first series resonator and the second series resonator and a second terminal electrically connected to the ground terminal. A resonance frequency of the first parallel resonator is higher than a resonance frequency of both of the first series resonator and the second series resonator and lower than an antiresonance frequency of both of the first series resonator and the second series resonator.
CASCADED RESONATOR
In a resonator, two interdigital transducers (W1,W2) are electrically series-connected and arranged next to each other in the longitudinal direction within an acoustic track delimited by reflectors. Between the two interdigital transducers, a transition area (UEB) is formed in that the finger period p, which is defined as the distance between the finger centers of adjacent transducer fingers, is higher in comparison to the remaining interdigital transducer.
Filter device and duplexer
In a filter device, first and second filter sections are connected in parallel between an input terminal and an output terminal. The first filter section is a longitudinally coupled resonator-type elastic wave filter including first and second inter-stage wiring lines with a two-stage cascading connection. The second filter section is a longitudinally coupled resonator-type elastic wave filter including third and fourth inter-stage wiring lines with a two-stage cascading connection. The phases of signals flowing in the third inter-stage wiring line and the second inter-stage wiring line are inverse. Terminal portions of an interdigital transducer electrode connected to the second inter-stage wiring line and an interdigital transducer electrode connected to the third inter-stage wiring line that are connected to a potential that is not a hot-side potential are connected by a virtual ground wiring line. A hot-side wiring portion that is adjacent to the virtual ground wiring line is disposed on an insulating film provided on the piezoelectric substrate.
Surface acoustic wave filter, surface acoustic wave filter device, and duplexer including a shared reflector
A surface acoustic wave filter includes a longitudinally coupled resonator first filter section and a longitudinally coupled resonator second filter section that is electrically connected to the first filter section in parallel or in series and that is provided next to the first filter section in a surface acoustic wave propagation direction. The first filter section includes a first interdigital transducer group arranged in the surface acoustic wave propagation direction. The second filter section includes a second interdigital transducer group arranged in the surface acoustic wave propagation direction. A reflector between the first interdigital transducer group and the second interdigital transducer group is an integrated shared reflector. A number of electrode fingers in reflecting units in the shared reflector is an odd number of no less than nine.