Murata Manufacturing Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Michiyo Yamamoto

Norihide Kinugasa

Akio Yokoyama

Mamoru Arayashiki

Hisashi Takahashi

A radio frequency module includes a filter that is arranged on a first path connecting a common terminal and a first input/output terminal and has a first frequency band as a pass band, another filter that is arranged on a second path connecting the common terminal and a second input/output terminal and has a second frequency band different from the first frequency band as a pass band, and a detection circuit connected to the first path and configured to detect a leakage signal in the second frequency band leaked to the first path and output a signal indicating a detection result.

Radio frequency module

A filter circuit includes a filter that is disposed on a path connecting a common terminal and an input output terminal and uses a first frequency band as a pass band, a filter that is disposed on a path connecting the common terminal and an input output terminal and uses a second frequency band different from the first frequency band as a pass band, and a phase adjustment circuit that has an input terminal connected to the path and an output terminal connected to the path, and adjusts a phase of a signal in the first frequency band input from the path and outputs a signal having a phase different from a phase of the signal in the first frequency band to the output terminal, wherein the path and the path are paths through which a received signal passes.

Filter circuit and communication device

A front-end circuit includes a first filter on a path connecting a common terminal and a first input/output terminal, a second filter on a path connecting the common terminal and a second input/output terminal, and a first switch on the path connecting the common terminal and the first input/output terminal. The first switch receives at least one of a first control signal and a second control signal. The first control signal increases a difference between a first voltage applied to the first switch to turn the first switch to a non-conductive state and a threshold voltage determining whether or not the first switch is turned to a conductive state. The second control signal increases a difference between a second voltage applied to the first switch to turn the first switch to the conductive state and the threshold voltage.

Front-end circuit

To tune the center frequency of a gm-C filter, which is a bandpass filter with a narrow bandwidth, to a target frequency, only while the filter is being tuned, the original circuit configuration of the filter is replaced with an alternative configuration that realizes a high signal-to-noise ratio. A characteristic tuner generates and inputs an impulse signal, pulse signal or step signal to the filter being tuned and thereby detects and adjusts the center frequency of the filter. And the tuning result is stored on a nonvolatile memory for future reuse. When the filter is operated, the characteristic tuner stops operating to cut down the power dissipation.

Growing community of inventors

Kyoto, Japan

Michiyo Yamamoto