Band-pass Josephson traveling wave parametric amplifier

Patent metadata

Field	Value
Publication number	US-11418162-B2
Application number	US-202016749949-A
Country	US
Kind code	B2
Filing date	Jan 22, 2020
Priority date	Jan 22, 2020
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

A bandpass parametric amplifier circuit includes a plurality of unit cells. At least one unit cell includes a first inductor having a first node coupled to a center conductor and a second node coupled to ground. There is a first capacitor having a first node coupled to the center conductor and a second node coupled to ground. There is a second inductor having a first node coupled to the center conductor. A second capacitor has a first node coupled to a second node of the second inductor. The second capacitor and the second inductor are in series with the center conductor.

First claim

What is claimed is:

1. A bandpass parametric amplifier circuit, comprising:
a plurality of unit cells, at least one of the unit cells comprising:
a first inductor having a first node coupled to a center conductor and a second node coupled to ground;
a first capacitor having a first node coupled to the center conductor and a second node coupled to ground;
a second inductor having a first node coupled to the center conductor;
a second capacitor having a first node coupled to a second node of the second inductor, wherein the second capacitor and the second inductor are in series with the center conductor;
a third capacitor having a first node coupled to the center conductor;
a third inductor having a first node coupled to a second node of the third capacitor, and a second node coupled to ground;
a fourth capacitor having a first node coupled to the second node of the third capacitor, and a second node coupled to ground.

2. The bandpass parametric amplifier of claim 1 , wherein the first and second inductors are non-linear.

3. The bandpass parametric amplifier of claim 1 , wherein the plurality of unit cells is part of a ladder circuit structure that creates the bandpass parametric amplifier circuit.

4. The bandpass parametric amplifier of claim 3 , wherein a number of unit cells in the ladder circuit structure is odd.

5. The bandpass parametric amplifier of claim 3 , wherein every multiple number of the unit cells further includes a resonant structure.

6. The bandpass parametric amplifier of claim 5 , wherein the multiple number is 3 to 9.

7. The bandpass parametric amplifier of claim 5 , wherein the resonant structures in each of the multiple number of unit cells define a stopband in a gain curve of the bandpass parametric amplifier.

8. The bandpass parametric amplifier of claim 5 , wherein the resonant structures in each of the multiple number of unit cells provide phase matching between a pump drive and a propagating in-band microwave signal amplified by the bandpass parametric amplifier.

9. The bandpass parametric amplifier of claim 1 , wherein the characteristic impedance of the bandpass filter is above 50 Ohm.

10. The bandpass parametric amplifier of claim 1 , wherein the bandpass parametric amplifier is part of a circulator circuit.

11. The bandpass parametric amplifier of claim 1 , wherein each of the first and second inductors comprises arrays of Josephson junctions.

12. The bandpass parametric amplifier of claim 11 , wherein each Josephson junction comprises aluminum (Al) or niobium (Nb) superconducting electrodes.

13. The bandpass parametric amplifier of claim 1 , wherein each of the first and second capacitors is constructed on a low-loss dielectric substrate in a coplanar waveguide geometry.

14. The bandpass parametric amplifier of claim 1 , wherein the bandpass parametric amplifier is a directional amplifier.

15. A method, comprising:
providing a plurality of unit cells;
for at least one of the unit cells:
providing a first inductor having a first node coupled to a center conductor and a second node coupled to ground;
providing a first capacitor having a first node coupled to the center conductor and a second node coupled to ground;
providing a second inductor having a first node coupled to the center conductor;
providing a second capacitor having a first node coupled to a second node of the second inductor, wherein the second capacitor and the second inductor are in series with the center conductor;
providing a third capacitor having a first node coupled to the center conductor;
providing a third inductor having a first node coupled to a second node of the third capacitor, and a second node coupled to ground;
providing a fourth capacitor having a first node coupled to the second node of the third capacitor, and a second node coupled to ground.

16. The method of claim 15 , wherein the first and second inductors are non-linear.

17. The method of claim 15 , further comprising, creating a bandpass parametric amplifier by using the plurality of unit cells as part of a ladder circuit structure.

18. The method of claim 17 , wherein a number of unit cells in the ladder circuit structure is odd.

19. The method of claim 17 , further comprising, for every multiple number of the unit cells, including a resonant structure.

20. The method of claim 19 , further comprising defining a stopband in a gain curve by the resonant structures realized in the multiple number of unit cells.

21. A Josephson based directional parametric amplifier, comprising:
a plurality of nonlinear distributed bandpass filters located along a transmission line; and
linear elements that implement a periodic resonant structure loading for pump drives, wherein each periodic resonant structure, comprises:
a third capacitor having a first node coupled to the center conductor;
a third inductor having a first node coupled to a second node of the third capacitor, and a second node coupled to ground; and
a fourth capacitor having a first node coupled to the second node of the third capacitor, and a second node coupled to ground.

22. The amplifier of claim 21 , wherein each nonlinear distributed bandpass filter comprises:
a first inductor having a first node coupled to a center conductor and a second node coupled to ground;
a first capacitor having a first node coupled to the center conductor and a second node coupled to ground;
a second inductor having a first node coupled to the center conductor; and
a second capacitor having a first node coupled to a second node of the second inductor, wherein the second capacitor and the second inductor are in series with the center conductor.

23. The amplifier of claim 21 , wherein the periodic resonant structure is added every 3 to 9 of the nonlinear distributed bandpass filters.

Assignees

• IBM

Inventors

• Abdo Baleegh

Classifications

• G06N10/40

  Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control · CPC title

• H03F2200/267

  A capacitor based passive circuit, e.g. filter, being used in an amplifying circuit · CPC title

• H01P1/20

  Frequency-selective devices, e.g. filters · CPC title

• H03F2200/423

  Amplifier output adaptation especially for transmission line coupling purposes, e.g. impedance adaptation · CPC title

• H03F3/60

  Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators (H03F3/54 takes precedence) · CPC title