Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Takayuki Yamada

Takayuki Okude

Kentaro Funahashi

Chihiro Shoda

Kentaro Kawasaki

A switch module switches among a first state where first and second frequency bands are used in parallel, a second state where only the first frequency band is used, and a third state where none of the first and second frequency bands is used, and includes first, second, and third filters and an antenna switch. In the first state, a common terminal and the first and second filters are connected and the common terminal and the third filter are not connected. In the second state, the common terminal and the first and third filters are connected, and the common terminal and the second filter are not connected.

Switch module

A band elimination filter includes a plurality of parallel resonators, each including a piezoelectric substrate and an IDT electrode on a surface of the piezoelectric substrate. The IDT electrode includes a pair of comb-shaped electrodes opposing each other, and the IDT electrode includes electrode fingers, a pitch of the electrode fingers being different between an end portion of the IDT electrode in a propagation direction of an elastic wave and a central portion of the IDT electrode different from the end portion.

Band elimination filter and composite filter

An elastic wave device includes a first piezoelectric substrate made of LiNbO, a first band-pass filter provided on the first piezoelectric substrate and including first IDT electrodes, a dielectric layer provided on the first piezoelectric substrate and covering the plurality of first IDT electrodes, a second piezoelectric substrate, a second band-pass filter provided on the second piezoelectric substrate, including second IDT electrodes, and differing from the first band-pass filter in pass band, and a band elimination filter connected to the first band-pass filter. The band elimination filter is provided on a piezoelectric substrate other than the first piezoelectric substrate.

Elastic wave device

A high-frequency module includes a longitudinally coupled surface acoustic wave filter and a low-noise amplifier that is connected to the surface acoustic wave filter. The input impedance of the surface acoustic wave filter connected to the low-noise amplifier differs from the output impedance thereof. On a Smith chart, the output impedance in the pass band of the surface acoustic wave filter is present in a region between a first output impedance and a second output impedance, the first output impedance being the output impedance of the surface acoustic wave filter where a gain of the low-noise amplifier is maximum, the second output impedance being the output impedance of the surface acoustic wave filter where a noise figure of the low-noise amplifier is minimum.

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Nagaokakyo, Japan

Takayuki Yamada