Murata Manufacturing Co., Ltd.

Takashi Ogami

Michio Kadota

Tetsuya Kimura

Katsuya Daimon

Hitoshi Tada

Masakazu Tani

Kansho Yamamoto

Hideaki Kobayashi

Shouzo Sugiyama

A variable filter circuit () includes a parallel arm () connected between a port (P) and node (A), a series arm () including a resonator (Re_s) connected in series between a port (P) and node (A), and a series arm () including a resonator (Re_s) connected in series between a port (P) and node (A). The parallel arm () includes a first inductor (Lp). The series arms () include variable capacitors (Cp_s, Cp_s) connected in parallel to the resonators (Re_s, Re_s).

Variable filter circuit and radio communication device

A variable filter circuit includes a serial arm connected between ports (P-P), a parallel arm having a resonator connected in series between ports (P-P), and another parallel arm having another resonator connected in series between ports (P-P). The serial arm includes a capacitor connected between the ports (P-P), and the parallel arms include variable capacitances connected in series to the resonators.

Variable filter circuit and wireless communication apparatus

An elastic wave device propagating plate waves includes a stack of an acoustic reflection layer, a piezoelectric layer, and IDT electrode on a supporting substrate. The piezoelectric layer is thinner than a period of fingers of the IDT electrode. The acoustic reflection layer includes low-acoustic-impedance layers and high-acoustic-impedance layers. The low-acoustic-impedance layers are made of SiO, and the high-acoustic-impedance layers are made of at least one material selected from the group consisting of W, LiTaO, AlO, AlN, LiNbO, SiN, and ZnO.

Elastic wave device and method for manufacturing the same

A tunable filter that is capable of magnifying a pass band width or increasing a frequency variable amount includes a resonator circuit portion provided in at least one of a series arm connecting an input terminal and an output terminal to each other and a parallel arm connecting the series arm and a ground potential to each other, a first variable capacitor is connected in series to the resonator circuit portion and a second variable capacitor is connected in parallel to the resonator circuit portion. The resonator circuit portion includes a piezoelectric substrate including LiNbOor LiTaO, an elastic wave resonator including an electrode located on the piezoelectric substrate, and a bandwidth extending inductance Lx, Lx connected to the elastic wave resonator.

Tunable filter

A Lamb wave device includes a base substrate, a piezoelectric thin film which is provided on the base substrate and which has a floating portion floating above the base substrate, the floating portion having a first surface facing the base substrate and a second surface opposite to the first surface, and an IDT electrode disposed on at least one of the first and the second surfaces of the piezoelectric thin film. The piezoelectric thin film is made of LiTaOor LiNbO, and the c-axis of the piezoelectric thin film is set in approximately the same direction as that of a line substantially perpendicular to the first and the second surfaces of the piezoelectric thin film, and the crystal structure of the piezoelectric thin film is a rotation twin crystal having the c-axis functioning as the rotation axis.

Growing community of inventors

Nagaokakyo, Japan

Takashi Ogami