Murata Manufacturing Co., Ltd.

Jin Yokoyama

Shiro Masumoto

Yukiya Yamaguchi

Morio Takeuchi

Motoji Tsuda

Atsushi Horita

Syunji Yoshimi

Yusuke Naniwa

Tomohide Aramata

Sho Matsumoto

Hiroyuki Kani

Yushi Sugimoto

Satoshi Tanaka

Tatsuya Tsujiguchi

Satoshi Arayashiki

Syunsuke Kido

Akio Kaneda

Kiwamu Sakano

Toru Yamaji

Seima Kondo

Junichi Yoshioka

Hiroyuki Furusato

Atushi Ono

A filter device includes a piezoelectric substrate including a high acoustic velocity material layer and a piezoelectric layer, and series and parallel arm resonators on the piezoelectric substrate. The parallel arm resonator includes a first IDT electrode on the piezoelectric substrate, and the series arm resonator includes a second IDT electrode on the piezoelectric substrate. First and second busbars of the first IDT electrode include opening formation regions, and an occupancy ratio of areas of openings in the first and second busbars of the first IDT electrode is greater than an occupancy ratio of areas of openings in first and second busbars of the second IDT electrode. In the first and second IDT electrodes, low acoustic velocity regions sandwich a central region. A high acoustic velocity region is provided in the opening formation region of each of the first and second busbars in the first IDT electrode.

Filter device

A transmit/receive module includes plural duplexers, a power amplifier, and a sending transmission line. The plural duplexers operate in bands different from each other and each includes a transmit filter and a receive filter. The power amplifier amplifies signals of pass bands of the plural transmit filters and outputs the amplified signals. The sending transmission line is connected to the plural transmit filters. The signals of the pass bands of the plural transmit filters output from the power amplifier are transmitted through the sending transmission line.

Transmit/receive module

A radio-frequency module includes a switch performing switching of the connection between a common terminal and a selection terminal, a reception filter having a reception band in a band A as a passband, a transmission filter that has a transmission band in a band B as a passband and has an output terminal connected to the selection terminal, a filter that has the transmission band in a band B as an attenuation band and has an input terminal connected to the selection terminal, a reception path which connects the selection terminal and an input terminal of the reception filter and on which the filter is disposed, a bypass path which connects the selection terminal and the input terminal of the reception filter and on which no filter is disposed, and a transmission path which connects the selection terminal and a transmission terminal and on which the transmission filter is disposed.

Radio-frequency module and communication device

A multiplexer includes an antenna terminal, first to third filters with different passbands, and first and second phase circuits that adjust the phase of a passing signal. The first filter is connected to the antenna terminal. The second filter is connected to the antenna terminal with the first phase circuit provided between the second filter and the antenna terminal. The third filter is connected to a connection node between the first phase circuit and the second filter with the second phase circuit provided between the third filter and the connection node. In the second filter, an unwanted wave is generated in the first passband of the first filter. The first phase circuit adjusts the phase to provide an impedance in an open state in the first passband at the antenna terminal. The second phase circuit adjusts the phase to provide the impedance in a short-circuited state in the first passband at the connection node.

Multiplexer

A radio-frequency module includes a transmission path which has one end connected to a transmission terminal and on which a transmission signal in Band A is transmitted; a reception path () which has one end connected to a reception terminal (B) and on which a reception signal in Band B is transmitted; a reception path () which has one end connected to a reception terminal (C) and on which a reception signal in Band C is transmitted; a switch () having a common terminal () and selection terminals (and); and a switch () having a common terminal () and selection terminals (and).

Radio-frequency module and communication apparatus

A transmit-and-receive module includes a multiplexer, a power amplifier, and a low-noise amplifier. The multiplexer includes a transmit filter and a receive filter. The power amplifier and the low-noise amplifier are integrated with each other. In a Smith chart, impedance in a receive band of the receive filter seen from a receive terminal intersects a line connecting a center point of noise figure circles and a center point of gain circles. The center point of the noise figure circles represents the impedance at which the noise figure of the low-noise amplifier is minimized. The center point of the gain circles represents the impedance at which the gain of the low-noise amplifier is maximized.

Transmit-and-receive module and communication device

A communication module includes an input/output switch, a duplexer, a transmit filter, and a receive filter. In the duplexer, a second side is disposed at a position farther from the input/output switch than a first side in a second direction orthogonal to a first direction. Any one of the transmit filter and the receive filter is disposed adjacent to the input/output switch in the first direction.

Communication module

A duplexer includes first and second filter circuits and first and second wirings. The first filter circuit allows a signal of a first frequency band to pass therethrough between a first terminal and a common terminal and includes a first resonator which is connected at one end to a line disposed between the first terminal and the common terminal to branch off from the line. The second filter circuit allows a signal of a second frequency band, which is different from the first frequency band, to pass therethrough between a second terminal and the common terminal. The first wiring is connected at one end to the common terminal and is opened at the other end. The second wiring is connected at one end to the other end of the first resonator and is grounded at the other end. The first wiring is electromagnetically coupled with second wiring.

Duplexer and front-end circuit

A ladder filter includes a series arm resonator and parallel arm resonators including a first parallel arm resonator defining a pass band together with the series arm resonator, and a second parallel arm resonator. Each of dimensions, in an overlap width direction, of gap regions between the overlap width region and first and second busbars in the second parallel arm resonator is larger than a dimension, in the overlap width direction, of a gap region in the first parallel arm resonator. A resonant frequency of the second parallel arm resonator is in a frequency range of not lower than a resonant frequency of the series arm resonator.

Ladder filter

A transmit-and-receive module includes a duplexer, a power amplifier, and a low-noise amplifier. The duplexer includes a transmit filter and a receive filter. The power amplifier and the low-noise amplifier are integrated with each other. In a Smith chart, impedance in a receive band of the receive filter seen from a receive terminal intersects a line connecting a center point of noise figure circles and a center point of gain circles. The center point of the noise figure circles represents the impedance at which the noise figure of the low-noise amplifier is minimized. The center point of the gain circles represents the impedance at which the gain of the low-noise amplifier is maximized.

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Kyoto, Japan

Jin Yokoyama