Superconducting Crossbar Switching with Variable Inductance Routing

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Solution Overview

Problem

Conventional microwave, electro-mechanical, and electronic switches are not compatible with on-chip integration and cryogenic operation of superconducting electronic circuits due to incompatible fabrication processes and high power dissipation, and tunable filters are difficult to control with single flux quantum (SFQ) technologies, especially at cryogenic temperatures.

Innovation Solution

A superconducting cross-bar switch system using variable inductance coupling elements, such as Josephson junctions, controlled by a switch controller to alternate between Bar and Cross states, allowing selective signal routing between input and output ports, and incorporating Superconducting Quantum Interference Devices (SQUIDs) to manage induced current for efficient signal switching at cryogenic temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional microwave, electro-mechanical, and electronic switches are used, then signal routing functionality is achieved, but compatibility with cryogenic operation and on-chip integration is lost due to incompatible fabrication processes and high power dissipation

Engineering Contradiction:
Improvecompatibility with cryogenic operationVSAvoidfabrication process compatibility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the operating parameters of the switch by using superconducting materials that operate at cryogenic temperatures, fundamentally altering the temperature parameter from room temperature to cryogenic ranges, thereby achieving compatibility with both cryogenic operation and on-chip integration while maintaining signal routing functionality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs composite superconducting structures combining multiple superconducting materials and designs (such as SQUID-based switches, superconducting diodes, and transistors) to achieve the desired properties of low power dissipation, cryogenic operation compatibility, and on-chip integrability simultaneously

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If conventional switches are used, then signal routing is achieved, but power dissipation is high making them incompatible with ultra-low-power consumption applications

Engineering Contradiction:
Improvepower consumptionVSAvoidpower dissipation
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent exploits the zero-resistance property of superconductors at cryogenic temperatures to eliminate ohmic power losses, changing the electrical resistance parameter from finite to effectively zero, thereby achieving ultra-low power consumption while maintaining signal routing capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces conventional electro-mechanical switching mechanisms with superconducting quantum interference device (SQUID) based switches that use magnetic flux control instead of mechanical movement or high voltage actuation, eliminating the power dissipation associated with mechanical friction and electrical resistance

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

3Ease of operation

If tunable filters using active components are used, then filter functionality is achieved, but controllability with SFQ signal levels is poor

Engineering Contradiction:
Improvecontrollability with SFQ signalsVSAvoidfilter tunability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent changes the control mechanism of tunable filters by using SQUID devices whose inductance can be precisely controlled by applying magnetic flux corresponding to single flux quantum (SFQ) signal levels, enabling direct control of filter characteristics with SFQ signals while maintaining full filter tunability

Inventive Principle:
Principle #35Parameter changes

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 system enables low-power, cryogenically operable, and SFQ-compatible signal routing with improved bandwidth and isolation, suitable for reconfigurable signal routing applications, while minimizing power dissipation and maintaining compatibility with SFQ control technologies.

Implementation Method 1

variable inductance coupling elements, such as Josephson junctions

Methodology Applied
Scientific EffectJosephson effect: Josephson Effect

Implementation Method 2

Superconducting Quantum Interference Devices (SQUIDs) to manage induced current for efficient signal switching at cryogenic temperatures

Methodology Applied
Scientific EffectSuperconducting Quantum Interference: Superconductivity

Data Source

PatentEP3360253B1Superconducting cross-bar switch system
Publication Date: 2021.03.10 NORTHROP GRUMMAN SYSTEMS CORP
  • EP3360253B1 patent drawingFigure 1~2
  • EP3360253B1 patent drawingFigure 3
  • EP3360253B1 patent drawingFigure 4

AI summary

A superconducting cross-bar switch system comprises a first input port coupled to a first output port through a first variable inductance coupling element, and a second output port through a third variable inductance coupling element, and a second input port coupled to the first output port through a second variable inductance coupling element, and the second output port through a fourth variable inductance coupling element. A switch controller controls the setting of the cross-bar switch between a Bar state and a Cross state by changing the variable inductance coupling elements between opposing inductance states. This allows for selective routing of signals between the first input port to the first output port and the second input port to the second output port in the Bar state, and the first input port to the second output port and the second input port to the first output port in the Cross state.