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 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.

Surface acoustic wave (SAW) filters and methods of fabricating SAW filters are disclosed. A filter includes a piezoelectric wafer having a thickness within one of a plurality of noncontiguous thickness ranges that define piezoelectric wafers upon which filter circuits meeting predetermined requirements can be fabricated according to a predetermined design using a predetermined fabrication process, and a filter circuit fabricated on the piezoelectric substrate according to the predetermined design using the predetermined fabrication process.

The present invention relates to a surface acoustic wave filter device with floating units. The surface acoustic wave filter device comprises a piezoelectric substrate, at least one interdigitated transducer configuration and at least one floating unit. The interdigitated transducer configuration comprises a plurality of interdigitated transducer units disposed on the piezoelectric substrate. The floating unit is disposed between adjacent interdigitated transducer units, and covers partial region of adjacent interdigitated transducer units to reduce the BAW scattering of the surface acoustic wave filter device, and can be used to improve the amplitude and phase balances of the surface acoustic wave filter devices.

An apparatus is disclosed for an acoustic resonator cascade. In example aspects, the apparatus includes at least one filter circuit. The at least one filter circuit includes a substrate, a first resonator cascade, and a second resonator cascade. The substrate has a surface including a first axis and a second axis. The first resonator cascade has multiple acoustic resonators and is disposed on the surface of the substrate in a first column along the first axis. The second resonator cascade has multiple acoustic resonators and is disposed on the surface of the substrate in a second column along the first axis. A first gap extends along the second axis between the first resonator cascade and the second resonator cascade. A second gap extends along the second axis between the first resonator cascade and the second resonator cascade. The first gap is different from the second gap.

Surface acoustic wave (SAW) filters and methods of fabricating SAW filters are disclosed. A filter includes a piezoelectric wafer having a thickness within one of a plurality of noncontiguous thickness ranges that define piezoelectric wafers upon which filter circuits meeting predetermined requirements can be fabricated according to a predetermined design using a predetermined fabrication process, and a filter circuit fabricated on the piezoelectric substrate according to the predetermined design using the predetermined fabrication process.

A duplexer includes a reception filter that is connected between a reception terminal and an antenna terminal and includes one or a plurality of series resonators that are acoustic wave resonators, and a transmission filter that is connected between a transmission terminal and the antenna terminal and includes one or a plurality of acoustic wave resonators, a resonance frequency of a first series resonator that is one of the one or the plurality of series resonators and is closest to the antenna terminal in the reception filter being higher than an upper limit frequency of a reception band of the reception filter.

The present invention relates to a surface acoustic wave filter device with floating units. The surface acoustic wave filter device comprises a piezoelectric substrate, at least one interdigitated transducer configuration and at least one floating unit. The interdigitated transducer configuration comprises a plurality of interdigitated transducer units disposed on the piezoelectric substrate. The floating unit is disposed between adjacent interdigitated transducer units, and covers partial region of adjacent interdigitated transducer units to reduce the BAW scattering of the surface acoustic wave filter device, and can be used to improve the amplitude and phase balances of the surface acoustic wave filter devices.