New surface acoustic wave interdigital transducers with narrow electrode gaps

Author

Yamanouchi, K. ; Meguro, T. ; Chen, Z.H. ; Matsumoto, K.

Author_Institution

Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan

fYear

1988

fDate

2-5 Oct 1988

Firstpage

63

Abstract

A surface acoustic wave (SAW) interdigital transducer (IDT) and a unidirectional transducer (UDT) are described. A description is given of the lift-off etching method and lift-off anodic oxidation fabrication method techniques used to get controllable narrow gaps between electrodes with good insulation. Experimental results show a 7.2-dB insertion loss with ripple of 1.2 dB for a conventional IDT, and directivities of 6-dB/transducer at 438 MHz for a floating-electrode-type unidirectional transducer (FEUDT) and 17 dB/transducer for its second harmonic at 868.5 MHz. A minimum insertion loss of 3.6 dB for a low-loss group type unidirectional transducer (GUDT) filter at 477 MHz were obtained

Keywords

surface acoustic wave devices; ultrasonic transducers; 438 MHz; 477 MHz; 868.5 MHz; IDT; SAW; UDT; interdigital transducer; lift-off anodic oxidation fabrication; lift-off etching; narrow electrode gaps; surface acoustic wave interdigital transducers; ultrasonic; unidirectional transducer; Acoustic transducers; Acoustic waves; Electrodes; Etching; Fabrication; Insertion loss; Insulation; Oxidation; Power harmonic filters; Surface acoustic waves;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1988. Proceedings., IEEE 1988

Conference_Location

Chicago, IL

Type

conf

DOI

10.1109/ULTSYM.1988.49343

Filename

49343