Reduced Kapitza resistance microwave filter for cryogenic environments

Patent metadata

Field	Value
Publication number	US-12142804-B2
Application number	US-202318449349-A
Country	US
Kind code	B2
Filing date	Aug 14, 2023
Priority date	Oct 2, 2018
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

First claim

What is claimed is:

1. A thermal decoupling device, comprising:
a dielectric material comprising a first channel that is separated from a second channel by a wall of the dielectric material, wherein the first channel and the second channel are in a pattern that facilitates a filter operation on a microwave signal propagated in a cryogenic environment;
a conductive line comprising a first segment and a second segment that respectively occupy the first channel and the second channel such that the first segment is thermally decoupled from the second segment; and
a housing configured to couple to refrigerator plates that facilitate a transfer of thermal energy away from the housing.

2. The thermal decoupling device of claim 1 , wherein the wall has dimensions that propagate the microwave signal based on the microwave signal having a frequency above about 1 gigahertz (GHz).

3. The thermal decoupling device of claim 1 , wherein the first segment and the second segment extend in directions substantially parallel, and wherein the first segment exhibits a first mean temperature greater than a second mean temperature of the second segment.

4. The thermal decoupling device of claim 1 , wherein the dielectric material is selected to have a thermal conductivity that is above 200 watts per meter-Kelvin (W/m-K) at a temperature at or below 77 degrees Kelvin (K).

5. The thermal decoupling device of claim 1 , wherein the dielectric material is selected from a group comprising sapphire and diamond.

6. The thermal decoupling device of claim 1 , wherein the wall has a maximum thickness that allows the microwave signal to pass through the wall, influenced by a frequency of the microwave signal, and a minimum thickness that reduces heat flow between the first segment and the second segment below a threshold, influenced by a thermal property of the wall.

7. The thermal decoupling device of claim 1 , wherein the conductive line comprises a conductive material that has been sintered in discontinuous channels of the dielectric material.

8. The thermal decoupling device of claim 1 , wherein the dielectric material comprises discontinuous channels, comprising the first channel and the second channel, and wherein the cryogenic environment has a temperature below about 77 degrees Kelvin (K).

9. The thermal decoupling device of claim 1 , wherein the filter operation is a function of a geometry of the conductive line that fills the first channel and the second channel having the pattern.

10. The thermal decoupling device of claim 1 , wherein the filter operation comprises a bandpass filter operation, wherein first frequencies of the microwave signal that are within a defined range of frequencies are passed by the bandpass filter operation, and wherein second frequencies beyond the defined range of frequencies are attenuated by the bandpass filter operation.

11. The thermal decoupling device of claim 10 , wherein the defined range of frequencies has a band width of approximately 1 gigahertz (GHz) that encompasses a portion of frequencies within a range of between about 1 GHz and about 10 GHz.

12. A thermally decoupled cryogenic microwave filter device, comprising:
one or more thermal decoupling devices, wherein a thermal decoupling device further comprises:
a dielectric material comprising a first channel that is separated from a second channel by a wall of the dielectric material, wherein the first channel and the second channel are in a pattern that facilitates a filter operation on a microwave signal propagated in a cryogenic environment;
a conductive line comprising a first segment and a second segment that respectively occupy the first channel and the second channel such that the first segment is thermally decoupled from the second segment; and
a housing configured to couple to refrigerator plates that facilitate a transfer of thermal energy away from the housing.

13. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the wall has dimensions that propagate the microwave signal based on the microwave signal having a frequency above about 1 gigahertz (GHz).

14. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the first segment and the second segment extend in directions substantially parallel, and wherein the first segment exhibits a first mean temperature that is greater than a second mean temperature of the second segment.

15. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the dielectric material is selected to have a thermal conductivity that is above 200 watts per meter-Kelvin (W/m-K) at a temperature at or below 77 degrees Kelvin (K).

16. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the dielectric material is selected from a group comprising sapphire and diamond.

17. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the wall has a maximum thickness that allows the microwave signal to pass through the wall, influenced by a frequency of the microwave signal, and a minimum thickness that reduces heat flow between the first segment and the second segment below a threshold, influenced by a thermal property of the wall.

18. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the conductive line comprises a conductive material that has been sintered in discontinuous channels of the dielectric material.

19. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the dielectric material comprises discontinuous channels, comprising the first channel and the second channel, and wherein the cryogenic environment has a temperature below about 77 degrees Kelvin (K).

20. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the filter operation is a function of a geometry of the conductive line that fills the first channel and the second channel having the pattern.

21. The thermally decoupled cryogenic microwave filter device of claim 12 , wherein the filter operation comprises a bandpass filter operation, wherein first frequencies of the microwave signal that are within a defined range of frequencies are passed by the bandpass filter operation, and wherein second frequencies beyond the defined range of frequencies are attenuated by the bandpass filter operation.

22. The thermally decoupled cryogenic microwave filter device of claim 21 , wherein the defined range of frequencies has a band width of approximately 1 gigahertz (GHz) that encompasses a portion of frequencies within a range of between about 1 GHz and about 10 GHz.

23. A thermal decoupling device, comprising:
a dielectric material comprising a first channel that is separated from a second channel by a wall of the dielectric material;
a conductive line comprising a first segment and a second segment that respectively occupy the first channel and the second channel, wherein the wall operates as a capacitor to allow a microwave signal to propagate between the first segment and the second segment; and
a housing configured to couple to refrigerator plates that facilitate a transfer of thermal energy away from the housing.

24. The thermal decoupling device of claim 23 , wherein the wall has dimensions that propagate the microwave signal based on the microwave signal having a frequency above about 1 gigahertz (GHz).

25. The thermal decoupling device of claim 23 , wherein th

Assignees

• IBM

Inventors

• Gumann Patryk
• Olivadese Salvatore Bernardo

Classifications

• H05K7/20372

  Cryogenic cooling; Nitrogen liquid cooling · CPC title

• H01B12/02

  characterised by their form · CPC title

• H01P1/203

  Strip line filters · CPC title

• H01P11/007

  Manufacturing frequency-selective devices (resonators H01P11/008) · CPC title

• H01P11/001

  Manufacturing waveguides or transmission lines of the waveguide type · CPC title