Patent ID: 8068001

Claim:
A surface acoustic wave (SAW) filter arrangement comprising an SAW filter, the SAW filter comprising: first electroacoustic transducers; at least one second electroacoustic transducer, the first electroacoustic transducers and the at least one second electroacoustic transducer being side-by-side in an acoustic path having an aperture A 0 ; wherein each first electroacoustic transducer is connected to an electrical output of the SAW filter, and the at least one second electroacoustic transducer is connected to an electrical input of the SAW filter; wherein each of the first electroacoustic transducers comprises a series circuit comprised of a number n partial transducers, each of the partial transducers having an individual aperture A j , with j=1, 2, . . . n and 1<n<6, where a sum of the individual apertures A j is equal to an aperture A 0 of the acoustic path; wherein at least two of the first electroacoustic transducers are connected in series; wherein the first electroacoustic transducers comprise bus bars that are on a first side of the acoustic path and that are connected to an electrical output; wherein there are an even number m of first electroacoustic transducers, with m≧4; wherein all electroacoustic transducers in the SAW filter are arranged symmetrically in relation to an axis of symmetry that is perpendicular to a propagation direction of an acoustic wave along the SAW filter; wherein first electroacoustic transducers on both sides of the axis of symmetry are connected to an electrical output that is among two parallel branches; wherein, on the second side of the acoustic path, first electroacoustic transducers are connected in one of the following ways: a) all first electroacoustic transducers are connected to ground; or b) two innermost first electroacoustic transducers, which are closest to the axis of symmetry, are connected in series, and other first electroacoustic transducers are connected to ground.