Piston mode lamb wave resonators
AssigneeSkyworks Solutions, Inc.
InventorsJie Zou, Jiansong Liu, Gong Bin Tang, Chih-Ming Lin, Chun Sing Lam
Life of this patent
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Abstract
Piston mode Lamb wave resonators are disclosed. A piston mode Lamb wave resonator can include a piezoelectric layer, such as an aluminum nitride layer, and an interdigital transducer on the piezoelectric layer. The piston mode Lamb wave resonator has an active region and a border region, in which the border region has a velocity with a lower magnitude than a velocity of the active region. The border region can suppress a transverse mode.
Claims20
A piston mode Lamb wave resonator with transverse mode suppression, the piston mode Lamb wave resonator comprising:
- an interdigital transducer electrode in contact with a piezoelectric layer;
- and
- an electrode in contact with the piezoelectric layer and positioned on an opposite side of the piezoelectric layer than the interdigital transducer electrode, the piston mode Lamb wave resonator having an active region and a border region, the border region having a first velocity with a lower magnitude than a second velocity of the active region, and the piston mode Lamb wave resonator configured to generate a Lamb wave in the piezoelectric layer.
An acoustic wave filter with a piston mode Lamb wave resonator, the acoustic wave filter comprising:
- an input node configured to receive a radio frequency signal;
- an output node;
- and
- a piston mode Lamb wave resonator coupled between the input node and the output node, the piston mode Lamb wave resonator including a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and an air cavity on an opposite side of the piezoelectric layer than the interdigital transducer electrode, the piston mode Lamb wave resonator being configured to generate a Lamb wave in the piezoelectric layer, the piston mode Lamb wave resonator having an active region and a border region, the border region having a fist velocity with a lower magnitude than a second velocity of the active region, and the acoustic wave filter being configured to filter the radio frequency signal.
A method of filtering a radio frequency signal using a piston mode Lamb wave resonator, the method comprising:
- providing the radio frequency signal to a filter that includes the piston mode Lamb wave resonator having an active region and a border region, the piston mode Lamb wave resonator including an aluminum nitride piezoelectric substrate, an interdigital transducer electrode in contact with a first side of the aluminum nitride piezoelectric substrate, and an electrode in contact with a second side of the aluminum nitride piezoelectric substrate, the second side opposing the first side;
- and
- filtering the radio frequency signal with the filter, the filtering including generating a Lamb wave in the aluminum nitride piezoelectric substrate, the border region having a first velocity with a lower magnitude that a second velocity of the active region.
Dependencies are inferred from the claim text.