Traveling Wave Parametric Amplifier With Discrete Pump Coupling

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Solution Overview

Problem

Conventional traveling wave parametric amplifiers face challenges in achieving broad bandwidth and frequency-multiplexed readout due to stopbands and complex control electronics, especially in devices using Josephson junctions, which require additional DC bias currents and flux-biased circuit elements.

Innovation Solution

A traveling wave parametric amplifier with a nonlinear transmission line and discrete coupling elements that compensate phase mismatch through interferometric phase adjustments, allowing for phase matching without a stopband and enabling high gain across a broad frequency range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional dispersion engineering is used to increase bandwidth, then bandwidth is improved, but stopbands are created in the middle of the gain profile

Engineering Contradiction:
ImprovebandwidthVSAvoidgain profile uniformity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The amplifier is divided into multiple discrete coupling elements along the nonlinear transmission line. Each coupling element couples pump signal portions into the transmission line at specific locations, creating a segmented structure that avoids continuous modulation and its associated stopbands while maintaining broad bandwidth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the phase of coupled-in pump signal portions at discrete locations along the transmission line. By adjusting phase parameters at specific coupling points rather than continuously modulating transmission line parameters, the system achieves broad bandwidth without creating stopbands in the gain profile.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If resonant phase matching with additional periodic filter circuits is used, then phase matching is improved, but device complexity and footprint increase

Engineering Contradiction:
Improvephase matchingVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the phase matching function from separate periodic filter circuits and integrates it directly into the coupling elements themselves. The coupling elements perform both signal coupling and phase adjustment functions, eliminating the need for additional filter circuits and reducing overall device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coupling elements merge multiple functions: they couple pump signals into the nonlinear transmission line, adjust the phase of coupled-in pump signal portions, and contribute to phase matching. This consolidation of functions reduces the number of separate components needed.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If continuous modulation of transmission line parameters is used, then phase matching is improved, but device complexity and power dependence increase

Engineering Contradiction:
Improvephase matchingVSAvoidcontrol complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of continuous modulation of transmission line parameters, the invention uses discrete coupling elements at specific locations. Each element provides localized phase adjustment through simple coupling mechanisms, avoiding the complex continuous control required by modulation techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention replaces complex continuous modulation control with a simpler discrete coupling approach. The phase matching is achieved through the spatial arrangement and coupling characteristics of discrete elements rather than through continuous electrical control of transmission line parameters.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves reliable amplification of signals with multiple frequencies, facilitating accurate frequency-multiplexed readout and reducing the need for complex control electronics, with high gain coefficients and tunable gain profiles.

Implementation Method 1

The nonlinear transmission line and the plurality of coupling elements are further configured to bring the coupled-in pump signal portions into interference with respect to each other along the nonlinear transmission line. Through the interference of the coupled-in pump signal portions a phase mismatch between the total pump signal, the target signal and its idler accumulated while co-propagating in the nonlinear transmission line is being compensated

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 2

four-wave mixing (4WM) devices, in which two pump photons at a time are converted in a signal and an idler photon

Methodology Applied
Scientific EffectFour-wave mixing:

Implementation Method 3

three-wave mixing (3WM) devices, in which single pump photons are converted in signal and idler photons

Methodology Applied
Scientific EffectThree-wave mixing:

Implementation Method 4

a nonlinear medium which provides a nonlinear mixing process used to amplify an incident target signal, a strong pump tone from which power is converted into signal and idler tones

Methodology Applied
Scientific EffectParametric amplification:

Data Source

PatentEP4625816A1Traveling wave parametric amplifier and manufacturing method, a method for amplifying a target signal, computer program and computer-readable data carrier
Publication Date: 2025.10.01 ETH ZURICH
  • EP4625816A1 patent drawingFigure 1
  • EP4625816A1 patent drawingFigure 2~3b
  • EP4625816A1 patent drawingFigure 4

AI summary

The invention relates to a traveling wave parametric amplifier (TWPA) for amplifying a target signal. The TWPA comprises a nonlinear transmission line (T1, T2) for receiving and propagating the target signal. The TWPA also comprises a plurality of coupling elements (DC1, DC2), wherein the plurality of coupling elements (DC1, DC2) are arranged at a distance from one another along the nonlinear transmission line (T1, T2). Each coupling element of the plurality of coupling elements (DC1, DC2) is configured to couple a pump signal portion from a pump feed line (D1) into the nonlinear transmission line (T1, T2), wherein the coupled-in pump signal portions form a total pump signal co-propagating in the nonlinear transmission line (T1, T2) in the same direction as the target signal for amplifying the target signal.