Title :
Experimental study on the performance of dithered single-phase unidirectional transducers (DSPUDT) and their filter applications on ST-quartz and LiTaO3 substrate materials
Author :
Chang, R.E. ; Thompson ; Wright, P.V.
Author_Institution :
RF Monolithics, Dallas, TX, USA
Abstract :
In this paper we present experimental results of the different reflection and transduction characteristics for transducers that have sampling rates of 1/3λ, 3/8λ, 2/5λ, 3/7λ, 5/12λ, and 5/14λ. Directivity tests on the different structures built on quartz and LiTaO3 were performed and compared. Wide band measurements of all transducers were taken as well. These measurements suggest the possibility of implementing a DSPUDT filter with mixed sampling rates in order to suppress unwanted spurious modes like group and bulk wave modes. As a result, a table with the best combinations of sampling rates for high frequency (above 550 MHz) and low frequency (below 550 MHz) DSPUDT filters on ST-quartz and Y112-LiTaO3 was generated. This table was used to implement a 916.5 MHz filter in ST-QUARTZ, and a 960 MHz and 350 MHz filter on Y112-LiTaO3
Keywords :
lithium compounds; quartz; signal sampling; surface acoustic wave filters; surface acoustic wave signal processing; surface acoustic wave transducers; ultrasonic reflection; 350 to 960 MHz; DSPUDT filter; LiTaO3; LiTaO3 substrate; ST-quartz; SiO2; directivity tests; dithered single-phase unidirectional transducers; filter applications; mixed sampling rates; reflection characteristics; sampling rates; spurious mode suppression; transduction characteristics; wide band measurements; Electrodes; Filters; Performance evaluation; Radio frequency; Reflection; Reflectivity; Sampling methods; Testing; Ultrasonic transducers; Wideband;
Conference_Titel :
Ultrasonics Symposium, 1996. Proceedings., 1996 IEEE
Conference_Location :
San Antonio, TX
Print_ISBN :
0-7803-3615-1
DOI :
10.1109/ULTSYM.1996.583767
