Title :
Sampling effect of distributed reflector arrays within a single-phase unidirectional SAW transducer
Author :
Saw, C.B. ; Campbell, C.K.
Author_Institution :
Bell Northern Res. Ltd., Ottawa, Ont., Canada
fDate :
3/1/1990 12:00:00 AM
Abstract :
A noteworthy feature of the group-type single-phase unidirectional transducer is that it can permit wideband low-loss surface-acoustic-wave (SAW) comb filter operation. This is shown to be due to the sampling imposed by the distributed reflector gratings. The capability is illustrated theoretically and experimentally for a 65-MHz comb filter on 128 degrees Y-X lithium niobate, with 5 comb modes of 585-kHz bandwidth each, together with 2.6-dB minimum insertion loss and overall 50% fractional bandwidth.<>
Keywords :
surface acoustic wave filters; 2.6 dB; 585 kHz; 65 MHz; LiNbO/sub 3/; bandwidth; comb filter; comb modes; distributed reflector arrays; fractional bandwidth; group-type single-phase unidirectional transducer; insertion loss; single-phase unidirectional SAW transducer; wideband low-loss surface-acoustic-wave; Bandwidth; Filters; Frequency; Gratings; Reflection; Reflectivity; Sampling methods; Surface acoustic waves; Transducers; Wideband;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
