CAVITY FILTER

• US 20150333386A1
• Filed: 05/15/2014
• Published: 11/19/2015
• Est. Priority Date: 05/15/2014
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: KANEDA, Noriaki, LIN, Tsu-Wei
• Granted Patent: US 9,379,423 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01P 1/202 Coaxial filters cascaded coaxial cavities H01P1/205
• CPC Class Codes: H01P 1/2053 the coaxial cavity resonators being disposed parall to each other
• CPC Class Codes: H01P 1/208 Cascaded cavities; Cascaded resonators inside a hollow waveguide structure H01P1/205 takes precedence
• CPC Class Codes: H01P 1/2084 with dielectric resonators
• CPC Class Codes: H01P 7/04 Coaxial resonators
• CPC Class Codes: H03J 7/16 where the frequency control is accomplished by mechanical means, e.g. by a motor

Abstract

In one embodiment, the cavity filter includes a housing defining a cavity, and at least one post projecting from a first interior surface of the housing towards a second interior surface of the housing. The first interior surface faces the second interior surface. The cavity filter further includes a thermo electric cooler disposed on the housing. The thermo electric cooler is configured to one of cool and heat at least a portion of the housing.

Claims

1. A cavity filter, comprising:

a housing defining a cavity;

at least one post projecting from a first interior surface of the housing towards a second interior surface of the housing, the first interior surface facing the second interior surface; and

a thermo electric cooler disposed on the housing, the thermo electric cooler configured to one of cool and heat at least a portion of the housing.

2. The cavity filter of claim 1, wherein the thermo electric cooler is disposed on an exterior surface of the housing.

3. The cavity filter of claim 2, wherein the thermo electric cooler is aligned with the post.

4. The cavity filter of claim 1, further comprising:

a controller configured to control the thermo electric cooler.

5. The cavity filter of claim 4, wherein the controller is configured to control the thermo electric cooler to one of expand and contract at least a portion of the housing and maintain a frequency characteristic of the cavity filter.

6. The cavity filter of claim 4, further comprising:

a temperature sensor; and

wherein

the controller is configured to control the thermo electric cooler based on output of the temperature sensor.

7. The cavity filter of claim 1, wherein

the housing includes a bottom, at least one side wall and a cover;

the post projects from the bottom towards the cover; and

the thermo electric cooler is disposed on the cover.

8. The cavity filter of claim 7, wherein the bottom includes a base having a first surface and an opposite second surface, the first surface is plated in a first conductive material, at least a portion of the first surface is an interior surface of the housing, the bottom includes first and second apertures, a first conductive strip is formed on the second surface and across the first aperture, and a second conductive strip is formed on the second surface and across the second aperture.

9. The cavity filter of claim 8, wherein the base is printed circuit board, the first conductive material is copper, the first conductive strip is formed of copper and the second conductive strip is formed of copper.

10. The cavity filter of claim 7, wherein the bottom, the cover and the side wall include printed circuit board.

11. The cavity filter of claim 10, wherein a first gap material fills the gap between the cover and the side wall, the first gap material being electrically and thermally conductive.

12. The cavity filter of claim 11, wherein a second gap material fills the gap between the cover and the post, and the second gap material is an insulator.

13. The cavity filter of claim 1, wherein a gap material fills the gap between the housing and the second interior surface, and the gap material is an insulator.

14. The cavity filter of claim 1, wherein the housing includes printed circuit board.

15. The cavity filter of claim 14, wherein the post includes one of a metal and a dielectric.

16. The cavity filter of claim 1, wherein

at least a portion of the housing on which the thermo electric cooler is disposed includes a first material;

and

the post includes a second material, and the second material has a lower coefficient of thermal expansion than the first material.

17. The cavity filter of claim 16, wherein the first material has a coefficient of thermal example greater than 100, and the second material has a coefficient of thermal expansion less than 30.

18. A method, comprising:

sensing a condition associated with a cavity filter;

obtaining, by a processor, a control parameter value based on the sensed condition; and

controlling a thermo electric cooler disposed on the cavity filter based on the obtained control parameter value.

19. The method of claim 18, wherein the sensed condition is ambient temperature.

20. The method of claim 18, wherein the sensed condition is a power level of a desired frequency at an output of the cavity filter.

21. The method of claim 18, wherein the obtaining comprises:

accessing a look up table stored in a memory based on the sensed condition, the look up table mapping possible sensed conditions to control parameter values.

22. A method, comprising:

changing a temperature of a material forming at least a portion of a cavity filter to control at least one dimension of the cavity filter.

23. The method of claim 22, wherein the changing changes the temperature using a thermo electric cooler such that the dimension is stabilized over temperature.

24. The method of claim 22, wherein the changing changes the temperature using a thermo electric cooler such that the dimension is controlled to tune an operating frequency of the cavity filter.