Surface acoustic wave two resonator filter using synchronous coupling interdigital transducers

A surface acoustic wave (SAW) two resonator filter with coupling interdigital transducers (IDTs) located inside the reflectors, was designed, fabricated, and tested. In the filter, electrodes of the coupling IDTs are in spatial synchronism with the reflectors' electrodes. The filter, fabricated on ST-cut quartz, had a center frequency of 302.6 MHz, insertion loss about 13 dB, and minimum rejection in the stopbands of about 40 dB.