Title :
SAW filters including one-focus slanted finger interdigital transducers
Author :
Martin, G. ; Steiner, B.
Author_Institution :
Inst. for Solid State & Mater. Res. Dresden, Germany
Abstract :
The present paper describes a new SFIT-filter type (SFIT: Slanted Finger Interdigital Transducer) that allows fast analysis as a precondition for fast optimization. Therefore, filter structure and analysis are especially suitable for optimizing Unidirectional SFIT (USFIT) filters. For analysis, a SFIT filter is usually divided into many narrow channels. Every channel is considered to be a subfilter and is analyzed separately. Therefore, the total filter analysis is very time consuming. For reducing computing time, we suggest a one-focus structure. As a result, the parameters of all subfilters can be calculated from the parameters of only one subfilter by simple frequency scaling. However, one-focus SFIT filters with continuous finger edges show a deep minimum within the passband. This problem can be overcome by using stepped one-focus structures
Keywords :
acoustic focusing; interdigital transducers; surface acoustic wave filters; surface acoustic wave transducers; SAW filter; design optimization; frequency scaling; slanted finger interdigital transducer; stepped one-focus structure; unidirectional SFIT filter; Band pass filters; Electrodes; Fingers; Frequency; Passband; Reflection; SAW filters; Solid state circuits; Transducers; Wideband;
Conference_Titel :
Ultrasonics Symposium, 2001 IEEE
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-7177-1
DOI :
10.1109/ULTSYM.2001.991575
