DocumentCode :
2769866
Title :
Beneficial effect of diffraction on the frequency response of a 250-MHz SAW mobile IF resonator-filter with long IDTs and triple longitudinal modes on quartz
Author :
Campbell, C.K.
Author_Institution :
Dept. of Electr. & Comput. Eng., McMaster Univ., Hamilton, Ont., Canada
Volume :
1
fYear :
1998
fDate :
1998
Firstpage :
159
Abstract :
Diffraction theory is applied to model the frequency response of a low-loss (~2 dB) 250-MHz SAW mobile IF resonator-filter (BW ~0.2%) with long-pair IDTs and triple longitudinal modes on ST-quartz, as applicable to circuitry such as for the Japanese Personal Handy Phone (PHP). In a simplified approach, a parabolic diffraction approximation is applied, with the IDT acoustic aperture conceptually sub-divided into parallel channel strips of equal widths. An anisotropy parameter value Ad =-0.22 for ST-quartz is used in the parabolic approximation. Frequency responses of individual segments are summed, using quadratically-shifted wave vector values in the parabolic diffraction approximation, together with Fraunhofer and phase corrections. Excellent agreement is obtained between theory and reported experimental frequency responses
Keywords :
Fraunhofer diffraction; cordless telephone systems; frequency response; interdigital transducers; land mobile radio; personal communication networks; quartz; radiofrequency filters; surface acoustic wave resonator filters; 2 dB; 250 MHz; Fraunhofer corrections; IDTs; PHP; Personal Handy Phone; SAW mobile IF resonator-filter; ST-quartz; SiO2; acoustic aperture; anisotropy parameter; diffraction theory; frequency response; parabolic diffraction approximation; parallel channel strips; phase corrections; quadratically-shifted wave vector; triple longitudinal modes; Acoustic diffraction; Anisotropic magnetoresistance; Apertures; Bandwidth; Fingers; Frequency response; Optical reflection; Resonance; Resonator filters; Surface acoustic waves;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 1998. Proceedings., 1998 IEEE
Conference_Location :
Sendai
ISSN :
1051-0117
Print_ISBN :
0-7803-4095-7
Type :
conf
DOI :
10.1109/ULTSYM.1998.762122
Filename :
762122
Link To Document :
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