Surface acoustic wave device

Patent metadata

Field	Value
Publication number	US-11894830-B2
Application number	US-201917418824-A
Country	US
Kind code	B2
Filing date	Dec 27, 2019
Priority date	Dec 28, 2018
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A surface acoustic wave device includes at least one transducer; two acoustic reflectors disposed on either side of the at least one transducer so as to form a cavity, each acoustic reflector comprising an array of electrodes in the form of lines parallel with each other, each array comprising a subset of electrodes connected to a reference potential denoted mass defining a first connection type, and a subset of electrodes that are not connected to any potential, i.e. that have a floating connection defining a second connection type; at least one switching circuit configured to modify the distribution of the connections of at least one part of the electrodes of each array between the different connection types.

First claim

The invention claimed is:

1. A frequency-agile surface acoustic wave device comprising:
at least one transducer (T 1 , T 2 ),
two acoustic reflectors (M 1 , M 2 ) disposed on either side of the at least one transducer so as to form a cavity, each acoustic reflector comprising an array of electrodes (R 1 , R 2 ) in the form of rows that are parallel to one another, each array comprising a subset of electrodes connected to a reference potential denoted ground (M) defining a first type of connection (CC), and a subset of electrodes which are not connected to any potential, that is to say which have a floating connection defining a second type of connection (CO),
at least one switching circuit (CCOM) configured to modify the distribution of the connections of at least a part of the electrodes of each array between the different types of connection.

2. The surface acoustic wave device as claimed in claim 1 , comprising one or two transducers.

3. The surface acoustic wave device as claimed in claim 1 , wherein each electrode can have only the first (CC) or the second (CO) type of connection.

4. The surface acoustic wave device as claimed in claim 1 , further comprising, for at least one subset of the electrodes of each mirror, an impedance (Z) between each of said electrodes of said subset and the ground, defining a third type of connection (CZ).

5. The surface acoustic wave device as claimed in claim 1 , wherein the distribution of the connections of the electrodes between the different types is symmetrical with respect to the at least one transducer.

6. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, connections of the electrodes are made individually.

7. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, electrodes are linked to one another defining bunches, the connection being made per bunch.

8. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, a subset of neighboring electrodes disposed at one end of the array is connected to the ground.

9. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, a subset of neighboring electrodes disposed at one end of the array has a floating connection.

10. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, electrodes form a periodic pattern, a pattern comprising at least one electrode connected to the ground and a floating electrode.

11. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, electrodes are linked individually to the switching circuit so that the modification of connection of said electrodes is applied individually.

12. The surface acoustic wave device as claimed in claim 1 , wherein, for each array, electrodes are linked to one another to form bunches, each bunch being linked to the switching circuit so that the modification of connection of the electrodes is applied per bunch.

13. A frequency filter comprising a surface acoustic wave device as claimed in claim 1 .

14. A frequency filter comprising a plurality of surface acoustic wave devices as claimed in claim 1 arranged in series and/or in parallel.

15. An oscillator comprising an inverting circuit (Inv) and a surface acoustic wave device as claimed in claim 1 arranged in parallel with said inverting circuit, the surface acoustic wave device comprising two transducers.

Assignees

• Thales Sa
• Centre Nat Rech Scient
• Frecnsys
• Yncrea Hauts De France Isen Lille
• Univ Lille
• Lille Ecole Centrale
• Univ Polytechnique Hauts De France
• Soitec Sa

Inventors

• Pham Colomban Thi Mai
• Prévot Claude
• Martins Paolo
• Hladky-Hennion Anne-Christine
• Dubus Bertrand
• Sagnard Marianne
• Laroche Thierry
• Ballandras Sylvain
• Croenne Charles

Classifications

• H03H9/14502 Primary

  Surface acoustic wave [SAW] transducers for a particular purpose · CPC title

• H03H9/02637 Primary

  Details concerning reflective or coupling arrays · CPC title

• H03H9/02992

  Details of bus bars, contact pads or other electrical connections for finger electrodes · CPC title

• H03H9/64

  using surface acoustic waves · CPC title

• H03H9/6403

  Programmable filters · CPC title