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US 11,515,855 B2Granted
Saw resonator and filter comprising same
AssigneeQUALCOMM Incorporated
InventorAndreas Bergmann
Life of this patent
Estimating the term…
Abstract
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.
Claims15
A band pass filter, comprising:
- a first series resonator, connected to an input of the band pass filter at an antenna side thereof;
- a DMS track;
- and
- a SAW resonator comprising two reflectors and a transducer arranged between the reflectors, wherein a resonant space between the transducer and one of the two reflectors enables an occurrence of a first resonance and at least a second resonance of a comparable admittance to the first resonance, wherein the SAW resonator is circuited as a parallel resonator in a parallel branch at an output of the DMS track, a mean finger period of the parallel resonator being chosen smaller than a mean finger period of the first series resonator and assigned to a frequency above a pass band of the DMS track.
1 more element
A SAW resonator, comprising two reflectors and a transducer arranged between the reflectors, wherein:
- a resonant space between the transducer and one of the two reflectors enables an occurrence of a first resonance and at least a second resonance of a comparable admittance to the first resonance,
- a local finger period is chirped on at least one of the two reflectors such that a local minimum of the local finger period forms in each of two transition regions that are between the transducer and the at least one of the two reflectors, and is defined at least in part by a number of outermost fingers on one or both of the transducer and the at least one of the two reflectors;
- and
- the local finger period across each of the two reflectors has a maximum at a beginning of at least one of the two transition regions and has a slope towards an outer end that faces away from the transducer where the local finger period has a value below the maximum.
1 more element
Dependencies are inferred from the claim text.