Ceramic temperature-compensated resonator

Patent metadata

Field	Value
Publication number	US-10310451-B2
Application number	US-201214355945-A
Country	US
Kind code	B2
Filing date	Oct 11, 2012
Priority date	Nov 4, 2011
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A temperature-compensated resonator including a body used in deformation, and a core of the body is formed by a material that is one of glass, ceramic glass, technical ceramic, and metallic glass. At least one part of the body includes a coating whose Young's modulus variation with temperature is of an opposite sign to that of the material used for the core, so that at least a first order frequency variation with temperature of the resonator is substantially zero.

First claim

The invention claimed is:

1. A temperature-compensated resonator comprising:
a body used in deformation, a core of the body being formed of fused quartz,
wherein at least one part of the body includes a coating whose Young's modulus variation with temperature is of an opposite sign to that of the fused quartz used for the core, and
the coating is a single coating including a thickness calculated based on a size and a sign of the Young's modulus variation with temperature of the coating, the thickness of the single coating is calculated to include values that affect at least both first and second orders of a frequency variation with temperature of the resonator, and at least the first and second orders of the frequency variation with temperature of the resonator are compensated to be substantially zero based on only the thickness of the single coating that is calculated.

2. The resonator according to claim 1 wherein the coating includes a metal, a metallic alloy, or silicon carbide.

3. The resonator according to claim 1 , wherein the coating includes chromium or titanium.

4. The resonator according to claim 1 , wherein the body has a substantially quadrilateral-shaped section whose faces are in identical pairs.

5. The resonator according to claim 1 , wherein the body includes a substantially quadrilateral-shaped section whose faces are entirely coated.

6. The resonator according to claim 1 , wherein the body is a bar wound around itself to form a balance spring and is coupled to an inertia fly-wheel.

7. The resonator according to claim 1 , wherein the body includes at least two symmetrically mounted bars to form a tuning fork.

8. The resonator according to claim 1 , wherein the body is a MEMS resonator.

9. The resonator according to claim 1 , wherein the coating is electrically conductive.

10. The resonator according to claim 1 , wherein the coating includes a positive Young's modulus variation with temperature for the first order frequency variation with temperature of the resonator and for the second order frequency variation with temperature of the resonator.

11. The resonator according to claim 1 , wherein the coating includes a negative Young's modulus variation with temperature for the first order frequency variation with temperature of the resonator and for the second order frequency variation with temperature of the resonator.

12. The resonator according to claim 1 , wherein the coating is a sole coating on the core of the body.

13. The resonator according to claim 1 , wherein the frequency variation with temperature of the resonator follows a relationship:

Δ
⁢

⁢
f

f
0

=

A
+

α
·

(

T
-

T
0

)

+

β
·

(

T
-

T
0

)

2

+

γ
·

(

T
-

T
0

)

3

where:

Δ
⁢

⁢
f

f
0

 is a relative frequency variation,
A is a constant which depends upon a point of reference,
T 0 is a reference temperature,
α is a first order thermal coefficient,
β is a second order thermal coefficient, and
γ is a third order thermal coefficient.

14. A temperature-compensated resonator comprising:
a body used in deformation, a core of the body being formed of a borosilicate glass or an aluminosilicate glass,
wherein at least one part of the body includes a coating whose Young's modulus variation with temperature is of an opposite sign to that of the borosilicate glass or the aluminosilicate glass used for the core, and
the coating is a single coating including a thickness calculated based on a size and a sign of the Young's modulus variation with temperature of the coating, the thickness of the single coating is calculated to include values that affect at least both first and second orders of a frequency variation with temperature of the resonator, and at least the first and second orders of the frequency variation with temperature of the resonator are substantially zero based on only the thickness of the single coating that is calculated.

15. A temperature-compensated resonator comprising:
a body used in deformation, a core of the body being formed of a photostructurable glass,
wherein at least one part of the body includes a coating whose Young's modulus variation with temperature is of an opposite sign to that of the photostructurable glass used for the core, and
the coating is a single coating including a thickness calculated based on a size and a sign of the Young's modulus variation with temperature of the coating, the thickness of the single coating is calculated to include values that affect at least both first and second orders of a frequency variation with temperature of the resonator, and at least the first and second orders of the frequency variation with temperature of the resonator are substantially zero based on only the thickness of the single coating that is calculated.

16. A temperature-compensated resonator comprising:
a body used in deformation, a core of the body being formed of ceramic glass,
wherein at least one part of the body includes a coating whose Young's modulus variation with temperature is of an opposite sign to that of the ceramic glass used for the core, and
the coating is a single coating including a thickness calculated based on a size and a sign of the Young's modulus variation with temperature of the coating, the thickness of the single coating is calculated to include values that affect at least both first and second orders of a frequency variation with temperature of the resonator, and at least the first and second orders of the frequency variation with temperature of the resonator are substantially zero based on only the thickness of th

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Hessler Thierry
• Dubois Philippe
• Conus Thierry

Classifications

• H03H2003/0407

  Temperature coefficient · CPC title

• H03H9/02448

  of temperature influence · CPC title

• H03H2003/027

  the resonators or networks being of the microelectro-mechanical [MEMS] type · CPC title

• H03H9/2468

  Tuning fork resonators · CPC title

• G04B17/22 Primary

  for the effect of variations of temperature {(alloys with small expansion coefficient C21C, C22C; adjustment of the regulator dependant on adjustment of the hands G04B18/028; depending on the difference in time with a comparison clockwork G04C11/007)} · CPC title