Centre National De La Recherche Scientifique

Stmicroelectronics S.a.

Pierre Jary

Didier Belot

Eric Kerherve

Alexandre Augusto Shirakawa

Jean-Marie Pham

Andreia Cathelin

Andrea Cathelin

A filter with coupled resonator having a substrate; an acoustic mirror intended to support acoustic resonators, and to isolate these resonators from the substrate; a first structure with an upper resonator and a lower resonator coupled to one another through at least one layer of acoustic coupling; a second structure with an upper resonator and a lower resonator coupled to one another through at least one layer of acoustic coupling; the lower resonators of the first and second structure having the same electrodes. The first and second structures are connected via a fifth resonator for which electrodes and the piezoelectric layer of the lower resonators are of the first and second structure.

Filtering circuit with coupled acoustic resonators

A Lamb wave resonator includes a piezoelectric layer, and a first electrode against a first face of the piezoelectric layer. The first electrode includes fingers and a contact arm, with each finger including a first side in contact with the contact arm and two other sides parallel to one another. Portions of the piezoelectric layer are at least partially etched between the two fingers to form a recess. The fingers are spaced apart from one another by a distance W calculated according to the following equation: 

Lamb wave resonator

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Talence, France

Pierre Jary