Toyo Communication Equipment Co., Ltd.

Takao Morita

Osamu Ishii

Takebumi Kurosaki

Kazuo Ono

Takehumi Kurosaki

Yuzo Nakazawa

Masaki Tanaka

Takefumi Kurosaki

Ultrathin multimode quartz crystal filter element

Electrodes and their lead structures of an ultrathin piezoelectric

Structure for a resonator using an ultrathin piezoelectric substrate

Structure for supporting a resonator using an ultrathin piezoelectric

A high frequency narrow-band pass multi-mode filter in constructed in such manner that SAW of SSBW resonators are closely disposed to each other on a single piezo-electric substrate to generate different vibration modes of different resonance frequencies, conditions that the resonators are acoustically coupled to each other to cause these vibration modes, are experimentally found, and the above conditions are satisfied by the filter. In order to reduce the ohmic loss of a very narrow common bus bar, the number of strip pairs of electrode in both interdigital transducers (hereinafter referred to as IDT) is minimized and instead reflectors are provided on the both sides of said TDTs to compensate for the reduction of its Q value. A part of the bus bar for the IDT electrodes is formed integral with some or all of gratings of the reflectors, whereby the connecting positions of the grating electrodes with respect to lead terminals can be positioned with a high freedom.

High frequency narrow-band multi-mode filter

Growing community of inventors

Kanagawa, Japan

Takao Morita