公开(公告)号：EP0100503A3

公开(公告)日：1986-02-26

申请号：EP83107258

申请日：1983-07-23

申请人： TOYO COMMUNICATION EQUIPMENT CO.,LTD.

发明人： Nakazawa, Yuzo Toyo Comm. Equipment Co. Ltd. ,  Ono, Kazuo Toyo Communication Equipment Co. Ltd. ,  Tanaka, Masaki Toyo Comm. Equipment Co. Ltd. ,  Morita, Takao Toyo Comm. Equipment Co. Ltd. ,  Kurosaki, Takefumi Toyo Comm. Equipment Co. Ltd.

IPC分类号： H03H09/64 ,  H03H09/145

CPC分类号： H03H9/6433 ,  H03H9/02944 ,  H03H9/6463

摘要： 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.