Title :
New resonator filter with high sidelobe suppression
Author :
Scholl, G. ; Dill, R. ; Ruile, W. ; Ruppel, C.C.W.
Author_Institution :
Siemens AG, Munich, Germany
Abstract :
A new resonator filter for IF applications which is superior to conventional approaches is reported. The design places acoustically coupled resonator cascades between two weighted single-phase unidirectional transducers (SPUDTs). This allows narrow bandwidth and small chip size, high sidelobe suppression, moderate group delay ripple and low loss at the same time. For full custom design sophisticated CAD tools are necessary. A filter was built at 225.0 MHz with a chip size smaller than 10 mm in a surface mounted device (SMD) package. The fractional bandwidth is 0.14%, sidelobes are suppressed more than 40 dB, the group delay ripple is smaller than 0.5 μs, and the insertion loss is 4.5 dB
Keywords :
acoustic resonators; cascade networks; crystal resonators; frequency response; radiofrequency filters; surface acoustic wave filters; surface mount technology; ultrasonic transducers; 225 MHz; 4.5 dB; SAW IF filter; SMD package; SPUDTs; acoustically coupled resonator cascades; fractional bandwidth; frequency response; group delay ripple; high sidelobe suppression; insertion loss; low loss; narrow bandwidth; resonator filter; small chip size; weighted single-phase unidirectional transducers; Acoustic waves; Bandwidth; Coupling circuits; Filtering; Frequency; Narrowband; Passband; Resonator filters; Surface acoustic waves; Transversal filters;
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
DOI :
10.1109/ULTSYM.1992.276054
