摘要:
A piezoelectric thin-film resonator includes a film laminate formed on a device substrate, the film laminate including a lower electrode, a piezoelectric film provided on the device substrate and the lower electrode, and an upper electrode provided on the piezoelectric film. At least one of the upper and lower electrodes has an electrode leading portion that extends from an membrane in which the upper electrode overlaps with the lower electrode through the piezoelectric film and has a width narrower than that of the membrane.
摘要:
An antenna duplexer includes two surface acoustic wave filters having different center frequencies and a phase matching circuit that matches phases of the two surface acoustic wave filters. A matching line pattern is provided on at least two layers between the two surface acoustic wave filters and transmission and reception terminals, and within an area specified by a sheet-like ground in a multilayered package, the multilayered package comprising multiple layers including a bonding layer on which wire bonding pads are provided for connecting to the two surface acoustic wave filters, and the matching line pattern having no portion provided on bonding layer.
摘要:
A surface acoustic wave element includes: metal patterns that include interdigital transducers, each of the metal patterns being formed with a first alloy or multi-layer film of metals having different standard electrode potentials; and metal films each formed with a second alloy or multi-layer film containing metals having different standard electrode potentials from the standard electrode potentials of the metals forming the first alloy or multi-layer film, the metal films being formed at least on a part of the regions other than the regions corresponding to the electrode fingers of the interdigital transducers of all the metal patterns that are electrically independent of one another.
摘要:
A piezoelectric thin-film resonator includes a lower electrode formed on a substrate to define a rounded dome-shaped cavity between the lower electrode and the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film. A membrane region is an overlapping region of the lower electrode and the upper electrode interposing the piezoelectric film and a projected area of the cavity onto the substrate includes the membrane region.
摘要:
A multi-mode surface acoustic wave filter device includes: a piezoelectric substrate; at least one input IDT (interdigital transducer) and at least one output IDT that are formed on the piezoelectric substrate; reflectors that are formed on the piezoelectric substrate and arranged on the external sides of the input IDT and the output IDT; an input terminal that supplies input signals to the input IDT; and an output terminal that receives output signals from the output IDT. In this multi-mode surface acoustic wave filter, the input terminal and the output terminal extend in the same direction.
摘要:
A piezoelectric thin-film resonator includes a film laminate formed on a device substrate, the film laminate including a lower electrode, a piezoelectric film provided on the device substrate and the lower electrode, and an upper electrode provided on the piezoelectric film. At least one of the upper and lower electrodes has an electrode leading portion that extends from an membrane in which the upper electrode overlaps with the lower electrode through the piezoelectric film and has a width narrower than that of the membrane.
摘要:
A duplexer includes: first and second filters including film bulk acoustic resonators (FBARs) arranged in a ladder form; first and second integrated-passive devices (IPDs) provided between a common terminal and the first and second filters; and a substrate on which the first and second filters and the first and second IPDs are mounted. The substrate includes conductive patterns that realize inductances connected between the first and second filters and ground. The first and second IPDs includes inductors connected to the first and second filters.
摘要:
A surface acoustic wave filter includes a series-arm resonators and parallel-arm resonators that are connected in a ladder-like structure, each having an interdigital transducer formed on a piezoelectric substrate, and at least one of the series-arm resonators having a different static capacitance from the other series-arm resonators. In this surface acoustic wave filter, at least one of the series-arm resonators except the series-arm resonator located at the first stage in the ladder-like structure has a lower average resonant frequency than the other series-arm resonators.