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AssigneeMurata Manufacturing Co., Ltd.
InventorsMasaki Takeuchi, Hajime Yamada, Hideki Kawamura, Daisuke Nakamura, Yukio Yoshino
Estimating the term…
A piezoelectric thin-film resonator includes a supporting substrate. A piezoelectric thin-film is formed on the supporting substrate. A lower electrode and an upper electrode are formed with the piezoelectric thin-film therebetween. The stiffness of at least one of the lower and upper electrodes is higher than that of the piezoelectric thin-film.
A piezoelectric thin-film resonator comprising:
A piezoelectric thin-film resonator comprising:
Dependencies are inferred from the claim text.
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Means for compensation or elimination of undesirable effects: of stress
Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output:…
Means for compensation or elimination of undesirable effects: of temperature influence
Means for compensation or elimination of undesirable effects: of ageing changes of characteristics, e.g. electro-acousto-migration
Term ended 4 Jul 2023 (estimated)
1. Field of the Invention
The present invention relates to a piezoelectric thin-film resonator used for filters in a high-frequency band (RF band, particularly, GHz band or more) of communication apparatuses, such as mobile phones. The present invention also relates to a piezoelectric filter including the resonator and an electronic component including the piezoelectric filter, such as a duplexer.
2. Description of the Related Art
FIG. 1 is a cross-sectional view showing the configuration of a piezoelectric thin-film resonator according to a first preferred embodiment of the present invention;
FIG. 2 is an enlarged view showing a portion of the piezoelectric thin-film resonator;
FIG. 3 shows the filter characteristics of a piezoelectric thin-film resonator of a comparative example in which Al is used for an upper electrode;
Hereinafter, preferred embodiments of the present invention of a piezoelectric thin-film resonator, a piezoelectric filter using the resonator, and a duplexer serving as an electronic component including the filter of the present invention will be described with reference to FIGS. 1 to 10.
First Preferred Embodiment
A method of manufacturing a piezoelectric thin-film resonator 10 according to the first preferred embodiment of the present invention will be described with reference to FIG. 1.