Murata Manufacturing Co., Ltd.

Miki Takamiya

Norio Taniguchi

Katsuhiro Ikada

Kenji Sakaguchi

A multiplexer includes a filter located between a common terminal and an individual terminal, and a filter that is located between the common terminal and an individual terminal and that has a pass band whose frequency is lower than the pass band of the filter. The filter includes serial arm resonators provided on the first path connecting the common terminal to the individual terminal. Each of the serial arm resonators includes a piezoelectric substrate and an IDT electrode which use leaky waves as principal acoustic waves. The occurrence frequency of the Rayleigh wave response of the serial arm resonator is different from that of the serial arm resonator.

Multiplexer, radio-frequency front-end circuit, and communication device

A surface acoustic wave filter includes a piezoelectric substrate, and at least two series arm resonators and at least one parallel arm resonator each constituted by a one-port surface acoustic wave resonator, disposed on the piezoelectric substrate. The at least two series arm resonators and at least one parallel arm resonator are connected to define a ladder-type circuit. Each of the at least two series arm resonators includes an interdigital transducer weighted by apodization, and the apodizations for the at least two series arm resonators are different from each other.

Surface acoustic wave ladder filter with two series resonators having different apodization weighting

A method of manufacturing a surface acoustic wave apparatus including the steps of forming a first conductive film, depositing a first resist on the first conductive film and patterning the first resist, dry-etching the first conductive film using the patterned first resist to form IDT electrodes, a short-circuit wiring electrode for establishing electrical connection between IDT electrodes, and a second conductive film provided where the second surface acoustic wave device is constructed, removing the second conductive film, depositing a second resist and heating the second resist, patterning the second resist on the electrodes, forming a second conductive film having a thickness which is different from the first conductive film, removing the second resist to form the electrodes of the second surface acoustic wave device and to expose the electrodes of the first surface acoustic wave device, and disconnecting the short-circuit wiring electrode.

Growing community of inventors

Kanazawa, Japan

Miki Takamiya