Murata Manufacturing Co., Ltd.

Keisuke Nishio

Syunsuke Kido

Masanori Kato

Hiroshi Matsubara

Yukiteru Sugaya

Masaki Tada

To suppress degradation of characteristics, a high frequency module includes a mounting substrate, a first signal terminal, a second signal terminal, and ground terminals, and a hybrid filter. The hybrid filter is coupled between the first signal terminal and the second signal terminal. The hybrid filter includes an acoustic wave filter having at least one acoustic wave resonator, a first inductor, and a capacitor. The pass band width of the hybrid filter is larger than that of the acoustic wave resonator. A resin layer is disposed on a first principal surface of the mounting substrate. The resin layer covers at least part of the acoustic wave filter. A metal electrode layer covers at least part of the resin layer, and is coupled to the ground terminals. The second inductor is coupled between the hybrid filter and the second signal terminal.

High frequency module and communication device

In a radio-frequency module, a hybrid filter includes an acoustic wave filter including at least one acoustic wave resonator, an inductor having a winding portion, and a capacitor. A plurality of outer electrodes of the acoustic wave filter includes a first input and output electrode connected to a first signal terminal, a second input and output electrode connected to a second signal terminal, and a ground electrode connected to a ground terminal. The inductor is disposed on a first major surface of a mounting substrate and is adjacent to the acoustic wave filter in plan view in a thickness direction of the mounting substrate. When viewed in a direction of a winding axis of the winding portion of the inductor, an inner part of the winding portion in the inductor does not overlap any of the first input and output electrode, the second input and output electrode, and ground electrode.

Radio-frequency module and communication device

A filter device having a pass band and a stop band on a lower frequency side than the pass band includes a filter having a pass band including the pass band, a series arm resonator connected in series to the filter, a first inductor directly connected in series to the series arm resonator, and a parallel arm resonator connected between a node on a path connecting the filter and the series arm resonator and the ground. The parallel arm resonator constitutes a resonance circuit having a resonant frequency at which an attenuation pole corresponding to a high frequency end of the first stop band, and the series arm resonator and the inductor constitute a resonance circuit having an anti-resonant frequency on a lower frequency side than the pass band and having a sub-resonant frequency higher than a resonant frequency of the resonance circuit.

Filter device and multiplexer

A filter includes first and second input/output terminals; an LC parallel resonance circuit that includes an inductor Land a capacitor Cconnected to each other in parallel; and an acoustic wave series resonance circuit that includes series arm resonators sand sconnected to each other in series. The LC parallel resonance circuit and the acoustic wave series resonance circuit are connected to each other in series between the first input/output terminal and the second input/output terminal.

Growing community of inventors

Kyoto, Japan

Keisuke Nishio