A SAW resonator comprises two reflectors and a transducer arranged between the reflectors. A resonant space between the transducer and a respective reflector is set large enough to enable occurrence of main resonance and at least one further resonance of comparable admittance. Thus, a multiple resonant resonator is achieved that can be used as a parallel resonator in a filter circuit with a DMS track for example to improve attenuation in a stop band.

A coupled cavity filter structure that uses a surface acoustic wave, in particular, a guided surface acoustic wave, comprises an acoustic wave propagating substrate, at least one input transducer structure and one output transducer structure, provided over the substrate, each comprising inter-digitated comb electrodes, at least one reflecting structure comprising at least one or more metallic strips, positioned at a distance and in between the input and output transducer structures, in the direction of propagation of an acoustic wave. The acoustic wave propagating substrate is a composite substrate comprising a base substrate and a piezoelectric layer. In additional embodiments, a coupled cavity filter structure comprises a groove. In additional embodiments, a SAW ladder filter device comprises at least two coupled cavity filter structures as described herein, wherein the at least two coupled cavity filter structures are positioned on a single line.

There is disclosed a surface acoustic wave sensor. An interdigital transducer (IDT) and a first reflector are formed on a surface of a piezoelectric substrate. The first reflector is displaced from the IDT in a direction of acoustic wave propagation. The first reflector includes a plurality of elongate reflective elements including a first reflective element and N additional reflective elements, where N is a positive integer. A long axis of each of the reflective elements is perpendicular to the direction of acoustic wave propagation, and a distance between adjacent reflective elements along the direction of acoustic wave propagation is a linear function of distance from the first reflective element along the direction of acoustic wave propagation.

A SAW resonator comprises two reflectors and a transducer arranged between the reflectors. A resonant space between the transducer and a respective reflector is set large enough to enable occurrence of main resonance and at least one further resonance of comparable admittance. Thus, a multiple resonant resonator is achieved that can be used as a parallel resonator in a filter circuit with a DMS track for example to improve attenuation in a stop band.

There is disclosed a surface acoustic wave sensor. An interdigital transducer (IDT) and a first reflector are formed on a surface of a piezoelectric substrate. The first reflector is displaced from the IDT in a direction of acoustic wave propagation. The first reflector includes a plurality of elongate reflective elements including a first reflective element and N additional reflective elements, where N is a positive integer. A long axis of each of the reflective elements is perpendicular to the direction of acoustic wave propagation, and a distance between adjacent reflective elements along the direction of acoustic wave propagation is a linear function of distance from the first reflective element along the direction of acoustic wave propagation.

A coupled cavity filter structure that uses a surface acoustic wave, in particular, a guided surface acoustic wave, comprises an acoustic wave propagating substrate, at least one input transducer structure and one output transducer structure, provided over the substrate, each comprising inter-digitated comb electrodes, at least one reflecting structure comprising at least one or more metallic strips positioned at a distance and in between the input and output transducer structures, in the direction of propagation of an acoustic wave. The acoustic wave propagating substrate is a composite substrate comprising a base substrate and a piezoelectric layer. In additional embodiments, a coupled cavity filter structure comprises a groove. In additional embodiments, a SAW ladder filter device comprises at least two coupled cavity filter structures as described herein, wherein the at least two coupled cavity filter structures are positioned on a single line.

A coupled cavity filter structure that uses a surface acoustic wave, in particular, a guided surface acoustic wave, comprises an acoustic wave propagating substrate, at least one input transducer structure and one output transducer structure, provided over the substrate, each comprising inter-digitated comb electrodes, at least one reflecting structure comprising at least one or more metallic strips positioned at a distance and in between the input and output transducer structures, in the direction of propagation of an acoustic wave. The acoustic wave propagating substrate is a composite substrate comprising a base substrate and a piezoelectric layer. In additional embodiments, a coupled cavity filter structure comprises a groove. In additional embodiments, a SAW ladder filter device comprises at least two coupled cavity filter structures as described herein, wherein the at least two coupled cavity filter structures are positioned on a single line.