Cryogenic-stripline microwave attenuator

Patent metadata

Field	Value
Publication number	US-10964993-B2
Application number	US-201916591225-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Mar 15, 2018
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

The technology described herein is directed towards a cryogenic-stripline microwave attenuator. A first high thermal conductivity substrate such as sapphire and a second high thermal conductivity substrate such as sapphire, along with a signal conductor comprising one or more attenuator lines between the substrates form a stripline. A compression component such as one or more screws, vias (plus clamps) and/or clamps presses the first high thermal conductivity substrate against one side of the signal conductor and presses the second high thermal conductivity substrate against another side of the signal conductor. The high thermal conductivity of the substrates facilitates improved thermalization, while the pressing of the substrates against the conductor reduces the thermal boundary (Kapitza) resistance and thereby, for example, improves thermalization and reduces thermal noise.

First claim

What is claimed is:

1. A device, comprising:
a cryogenic-stripline microwave attenuator, comprising,
a signal conductor comprising one or more attenuator lines between a first high thermal conductivity substrate and a second high thermal conductivity substrate, the signal conductor compressed by compression components that press the first high thermal conductivity substrate against one side of the signal conductor and presses the second high thermal conductivity substrate against another side of the signal conductor, wherein the compression components are arranged to provide increased compression in locations of the first high thermal conductivity substrate and second high thermal conductivity substrate in contact with the signal conductor relative to other locations of the first high thermal conductivity substrate and second high thermal conductivity substrate not in contact with the signal conductor.

2. The device of claim 1 , wherein the compression components comprise at least one via.

3. The device of claim 1 , wherein the compression components comprise at least one screw.

4. The device of claim 1 , wherein the compression components comprise at least one clamping component.

5. The device of claim 1 , wherein the compression components facilitates thermal conductivity between the first high thermal conductivity substrate, the second high thermal conductivity substrate, and the signal conductor.

6. The device of claim 1 , wherein the compression components reduces thermal boundary resistance between the first high thermal conductivity substrate, the second high thermal conductivity substrate, and the signal conductor to increase thermal conductivity.

7. The device of claim 1 , wherein the first high thermal conductivity substrate has a thermal conductivity of at least 200 Watts per meter-Kelvin.

8. The device of claim 1 , wherein the first high thermal conductivity substrate has a thickness of 0.5 to 1.0 millimeter.

9. The device of claim 1 , wherein the second high thermal conductivity substrate has a thermal conductivity of at least 200 Watts per meter-Kelvin.

10. The device of claim 1 , wherein the second high thermal conductivity substrate has a thickness of 0.5 to 1.0 millimeter.

11. The device of claim 1 , the second high thermal conductivity substrate has a thermal conductivity of at least 150 Watts per meter-Kelvin.

12. The device of claim 1 , wherein the first high thermal conductivity substrate has a thermal conductivity of at least 100 Watts per meter-Kelvin, and the second high thermal conductivity substrate has a thermal conductivity of at least 100 Watts per meter-Kelvin.

13. The device of claim 1 , wherein the first high thermal conductivity substrate has a thermal conductivity of at least 150 Watts per meter-Kelvin.

14. A device, comprising:
an attenuator, comprising,
compression components that presses a first high thermal conductivity substrate against a side of a signal conductor, and presses a second high thermal conductivity substrate against another side of the signal conductor, wherein the compression components are arranged to provide increased compression in locations of the first high thermal conductivity substrate and second high thermal conductivity substrate in contact with the signal conductor relative to other locations of the first high thermal conductivity substrate and second high thermal conductivity substrate not in contact with the signal conductor.

15. The device of claim 14 , wherein the compression components comprises at least one via, or at least one screw.

16. The device of claim 14 , wherein the first high thermal conductivity substrate has a thickness of 0.5 to 1.0 millimeter and wherein the second high thermal conductivity substrate has a thickness of 0.5 to 1.0 millimeter.

17. The device of claim 14 , wherein the signal conductor comprises attenuator lines and resistors substantially forming a cross shape.

18. The device of claim 14 , wherein the compression components facilitates thermal conductivity of the signal conductor and reduces thermal boundary resistance between the substrates and the signal conductor.

19. A cryogenic-stripline microwave attenuator, comprising,
a signal conductor having a substantially flat first side and a substantially flat second side opposite the substantially flat first side; and
compression components that presses a first high thermal conductivity substrate against the substantially flat first side of the signal conductor, and presses a second high thermal conductivity substrate pressed against the substantially flat second side of the signal conductor, wherein the compression components are arranged to provide increased compression in locations of the first high thermal conductivity substrate and second high thermal conductivity substrate in contact with the signal conductor relative to other locations of the first high thermal conductivity substrate and second high thermal conductivity substrate not in contact with the signal conductor.

20. The device of claim 19 , wherein the second high thermal conductivity substrate has a thermal conductivity of at least 120 Watts per meter-Kelvin.

21. The device of claim 19 , wherein the first high thermal conductivity substrate has a thermal conductivity of at least 120 Watts per meter-Kelvin.

22. A cryogenic-stripline microwave attenuator, comprising:
a signal conductor having a first side pressed against a first high thermal conductivity substrate by compression components, and having a second side pressed against a second high thermal conductivity substrate by the compression components, wherein the compression components are arranged to provide increased compression in locations of the first high thermal conductivity substrate and second high thermal conductivity substrate in contact with the signal conductor relative to other locations of the first high thermal conductivity substrate and second high thermal conductivity substrate not in contact with the signal conductor; and
wherein within a dilution refrigerator, the signal conductor receives an input signal and attenuates the input signal into an attenuated signal at an output of the cryogenic-stripline microwave attenuator.

23. The cryogenic-stripline microwave attenuator of claim 22 , wherein the first high thermal conductivity substrate and the second high thermal conductivity substrate respectively have thermal conductivity of at least 120 Watts per meter-Kelvin.

24. A method for constructing a cryogenic-stripline microwave attenuator, comprising:
embedding attenuator lines between a first high thermal conductivity substrate and a second high thermal conductivity substrate; and
pressing, via compression components:
the first high thermal conductivity substrate against a side of the signal conductor, and
the second high thermal conductivity substrate against another side of the signal conductor, wherein the compression components are arranged to provide increased compression in locations of the first high thermal conductivity substrate and second high thermal conductivity substrate in contact with the signal conductor relative to other locations of the first high thermal conductivity substrate and second high thermal conductivity substrate not in contact with the signal conductor.

25. The method of claim 18 , further comprising, locating the cryogenic-stripline microwave attenuator in a cryogenic dilution refrigerator of a quantu

Assignees

• IBM

Inventors

• Olivadese Salvatore Bernardo
• Gumann Patryk
• Gambetta Jay M
• Chow Jerry M

Classifications

• H01P11/003

  Manufacturing lines with conductors on a substrate, e.g. strip lines, slot lines · CPC title

• H01P1/227 Primary

  Strip line attenuators (H01P1/23 takes precedence) · CPC title

• H01P3/08

  Microstrips; Strip lines · CPC title

• H01P1/30

  for compensation of, or protection against, temperature or moisture effects {; for improving power handling capability (H01P1/04, H01P1/08 take precedence)} · CPC title