Taiyo Yuden Co., Ltd.

Masufumi Iwaki

Masanori Ueda

Motoaki Hara

Takashi Matsuda

Tokihiro Nishihara

Shinji Taniguchi

Jun Tsutsumi

Takeshi Sakashita

Tsuyoshi Yokoyama

Shogo Inoue

Go Endo

In a high frequency device, resonators (IDT capacitors) that function as capacitors are included in a lumped constant balun included in a filter or duplexer, and furthermore, the resonance frequency of the IDT capacitors is set higher than the passband frequency of the filter. This improves the capacitor Q value, thus enabling the realization of a low-loss balance filter.

High frequency device, filter, duplexer, communication module, and communication apparatus

A resonator includes a substrate, a lower electrode, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film. The lower electrode includes a first film provided on the substrate, and a second film that is provided on the first film and has a specific gravity greater than that of the first film. The piezoelectric film is provided on the second film. The upper electrode includes a third film provided on the piezoelectric film, and a fourth film provided on the third film, the third film having a specific gravity greater than that of the fourth film. The third film is thicker than the second film.

Resonator, filter and electronic device

Growing community of inventors

Kawasaki, Japan

Masufumi Iwaki