Transversal lamb wave filter with improved out of band rejection
AssigneeSkyworks Solutions, Inc.
InventorsSiarhei Dmitrievich Barsukou, Hiroyuki Nakamura
Life of this patent
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Abstract
A Lamb wave filter is provided which has improved out of band rejection, the filter including a substrate having a center region and two edge regions, a first set of electrodes arranged as a first interdigital transducer displaced on one of the two edge regions and configured to receive an input signal, a second set of electrodes arranged as a second interdigital transducer displaced on the other of the two edge regions and configured to provide a filtered output signal, and a third set of electrodes disposed parallel to the first and second sets of electrodes on the center region of the substrate.
Claims21
A circuit comprising:
- a first Lamb wave filter including a substrate having a center region and two edge regions and configured to propagate a first Lamb wave within, a first set of electrodes arranged as a first interdigital transducer disposed on one of the two edge regions and configured to receive an input signal, a second set of electrodes arranged as a second interdigital transducer disposed on the other of the two edge regions and configured to provide a filtered output signal, and a third set of electrodes disposed parallel to the first and second sets of electrodes on the center region of the substrate;
- and
- a second Lamb wave filter including a second substrate having a second center region and two second edge regions and configured to propagate a second Lamb wave within, a fourth set of electrodes arranged as a third interdigital transducer disposed on one of the two second edge regions and configured to receive an input signal, a fifth set of electrodes arranged as a fourth interdigital transducer disposed on the other of the two second edge regions and configured to provide a filtered output signal, and a sixth set of electrodes disposed parallel to the fourth and fifth sets of electrodes on the second center region of the second substrate, the first filter and the second filter connected in parallel such that the first set of electrodes of the first filter is connected to the fourth set of electrodes of the second filter, and the second set of electrodes of the first filter is connected to the fifth set of electrodes of the second filter, the first set of electrodes and the fourth set of electrodes configured to receive the same input signal and the second and fourth interdigital transducers configured to jointly output a filtered signal, the first and second Lamb wave filters having same relative bandgaps.
A circuit comprising:
- a first filter including a substrate having a center region and two edge regions and configured to propagate a first Lamb wave within, a first set of electrodes arranged as a first interdigital transducer disposed on one of the two edge regions and configured to receive an input signal, a second set of electrodes arranged as a second interdigital transducer disposed on the other of the two edge regions and configured to provide a filtered output signal, an entirety of the center region of the substrate extending between the first interdigital transducer and the second interdigital transducer being free of electrodes;
- and
- a second filter including a second substrate having a second center region and two second edge regions and configured to propagate a second Lamb wave within, a third set of electrodes arranged as a third interdigital transducer disposed on one of the two second edge regions, a fourth set of electrodes arranged as a fourth interdigital transducer disposed on the other of the two second edge regions, and a fifth set of electrodes disposed parallel to the third and fourth sets of electrodes on the second center region of the second substrate, the first filter and the second filter connected in a series parallel configuration such that the second set of electrodes of the first filter is connected to the third set of electrodes of the second filter, the fourth set of electrodes of the second filter is connected to ground, the first set of electrodes of the first filter is configured to receive an input signal and the second set of electrodes of the first filter and the third set of electrodes of the second filter are configured to jointly output a filtered signal.
A circuit comprising:
- a first filter including a substrate having a center region and two edge regions and configured to propagate a first Lamb wave within, a first set of electrodes arranged as a first interdigital transducer disposed on one of the two edge regions and configured to receive an input signal, a second set of electrodes arranged as a second interdigital transducer disposed on the other of the two edge regions and configured to provide a filtered output signal, and a third set of electrodes disposed parallel to the first and second sets of electrodes on the center region of the substrate;
- and
- a second filter including a second substrate having a second center region and two second edge regions and configured to propagate a second Lamb wave within, a fourth set of electrodes arranged as a third interdigital transducer disposed on one of the two second edge regions and configured to receive an input signal, a fifth set of electrodes arranged as a fourth interdigital transducer disposed on the other of the two second edge regions and configured to provide a filtered output signal, and a sixth set of electrodes disposed parallel to the fourth and fifth sets of electrodes on the second center region of the second substrate, the first filter and the second filter connected in series such that the second set of electrodes of the first filter is connected to the fourth set of electrodes of the second filter, the first set of electrodes of the first filter configured to receive an input signal and the fifth set of electrodes of the second filter is configured to output a filtered signal, the first filter and the second filter having different bandgaps and same passbands.
Dependencies are inferred from the claim text.