Abstract: A SAW ladder filter includes grating pads extending from opposing bus bars and interdigital transducer electrodes extending from the grating pads for defining an acoustic aperture. The metalization ratio for the grating pads is greater than that for the interdigital transducer electrodes. Reflector electrodes are disposed on opposing longitudinal sides of the interdigital transducer electrodes. Operation of the filter results in a velocity of the SAW along the grating pads slower than a SAW velocity along the plurality of interdigital transducer electrodes, thus producing a wave guiding effect for optimizing SAW propagation within the acoustic aperture. The grating pads may be longitudinally offset from cooperating interdigital transducer electrodes using minor bus bars.

Abstract: A SAW filter useful in cellular telephone communications includes SAW resonator elements provided in a series and parallel branches for forming a ladder filter network, and SAW resonator elements connected in parallel and provided in the series branch of the SAW filter for providing improved ESD protection to the SAW filter. The SAW filter is effectively used with an ESD protection circuit and a triplexer for receiving and separating low, high, and bandpass frequencies.