Title :
Nonequidistant uniform-beam-profile IDTs in broadband SAW filters
Author :
Bausk, Evgeniy V. ; Kolosovsky, Evgeniy A.
Author_Institution :
Inst. of Semicond. Phys., Acad. of Sci., Novosibirsk, Russia
Abstract :
An optimization algorithm has been developed for the design of nonequidistant SAW transducers with uniform electrode length. Equidistant transducers weighted by assignment of polarities of individual electrodes are used as initial ones for this procedure. A set of SAW filters with bandwidth of 2-7%, shape factor of 1.2-1.5 has been designed using the suggested algorithm. The improvement of out-of-band rejection for filters with nonequidistant transducers is 3-6 dB in wide stopbands or 5-10 dB in most important narrow frequency regions as compared with equidistant analogs. In addition, the proposed algorithm can synthesize specified nonsymmetric frequency responses
Keywords :
frequency response; interdigital transducers; optimisation; surface acoustic wave filters; surface acoustic wave transducers; broadband SAW filters; nonequidistant SAW transducers; nonequidistant uniform-beam-profile IDT; optimization algorithm; out-of-band rejection; specified nonsymmetric frequency responses; uniform electrode length; Acoustic transducers; Algorithm design and analysis; Design optimization; Electrodes; Frequency response; Nonlinear equations; Physics; SAW filters; Shape; Surface acoustic waves;
Conference_Titel :
Frequency and Time Forum, 1999 and the IEEE International Frequency Control Symposium, 1999., Proceedings of the 1999 Joint Meeting of the European
Conference_Location :
Besancon
Print_ISBN :
0-7803-5400-1
DOI :
10.1109/FREQ.1999.841464
