Wideband low loss double mode SAW filters

Author

Morita, Takahito ; Watanabe, Yoshitaka ; Tanaka, Masaki ; Nakazawa, Yuzo

Author_Institution

Toyo Commun. Equipment Co. Ltd., Kanagawa, Japan

fYear

1992

Firstpage

95

Abstract

A method is discussed for achieving a wideband low-loss longitudinally coupled double mode surface acoustic wave (SAW) (DMS) filter using a leaky SAW on a 36° Y-X LiTaO₃ and 64° Y-X LiNbO₃ substrate with a high electromechanical coupling factor. Its characteristics are analyzed by computer simulation. With the use of the first-mode and third-mode resonance on a 64° Y-X LiNbO₃ substrate and the selection of the optimum values for the distance between input and output interdigital transducers (IDTs), the electrode film thickness and the input/output IDT pair number, it is possible to achieve favorable characteristics with a 1-dB bandwidth of 33 MHz, and insertion loss of 2.1 dB, and an attenuation in the rejection band of 28 ~ 38 dB

Keywords

acoustic impedance; frequency response; losses; radiofrequency filters; surface acoustic wave filters; 1-dB bandwidth; 2.1 dB; 33 MHz; 836.5 MHz; 930.5 MHz; I/O IDT distance; LiNbO₃ substrate; LiTaO₃ substrate; Y-X substrate; computer simulation; electrode film thickness; first mode resonance; frequency response; high electromechanical coupling factor; impedance; input/output IDT pair number; insertion loss; leaky SAW; longitudinal coupling; output interdigital transducers; rejection band attenuation; third-mode resonance; wideband low loss double mode SAW filter; Acoustic waves; Bandwidth; Computer simulation; Electrodes; Resonance; SAW filters; Substrates; Surface acoustic waves; Transducers; Wideband;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1992. Proceedings., IEEE 1992

Conference_Location

Tucson, AZ

Print_ISBN

0-7803-0562-0

Type

conf

DOI

10.1109/ULTSYM.1992.276057

Filename

276057