SQUID Switch Topology for Cryogenic Signal Routing and Filtering
Find Innovative SolutionsGenerate Solutions
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 using superconducting materials face challenges with signal control and operation at cryogenic temperatures, leading to issues like high return loss and limited bandwidth.
Innovation Solution
A superconducting single-pole double-throw switch system utilizing Superconducting Quantum Interference Devices (SQUIDs) with variable inductance coupling elements and a switch controller to control inductance states, allowing selective routing of signals between paths and enabling band-pass filtering, while maintaining compatibility with cryogenic operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional microwave, electro-mechanical, and electronic switches are used, then switching function is provided, but compatibility with on-chip integration and cryogenic operation is lost due to incompatible fabrication processes and high power dissipation
Solution Approach 1:
The patent replaces conventional mechanical and electronic switches with a superconducting SQUID-based switch system that operates using magnetic flux control instead of mechanical movement or conventional electronic switching mechanisms. This substitution enables compatibility with superconducting circuit fabrication processes and cryogenic operation while maintaining low power dissipation
Solution Approach 2:
The patent changes the operating parameters by using variable inductance coupling elements within the SQUID structure that can be controlled through magnetic flux. This allows the switch to operate in the superconducting regime at cryogenic temperatures with fabrication processes compatible with superconducting circuits, resolving the contradiction between manufacturing compatibility and energy loss
2Temperature
If tunable filters using superconducting materials are used, then operation at cryogenic temperatures is achieved, but signal control is limited and bandwidth is restricted due to high return loss
Solution Approach 1:
The patent introduces dynamic control capability by using variable inductance coupling elements within the SQUID structure that can be adjusted through magnetic flux control. This allows real-time tuning of the filter characteristics and signal routing without losing cryogenic operation capability, thereby improving signal control flexibility while maintaining low temperature operation
Solution Approach 2:
The SQUID-based switch system serves multiple functions including signal routing, filtering, and switching operations within a single integrated structure. This multi-functionality provides versatile signal control at cryogenic temperatures while avoiding the limitations of separate filter and switch components
3Temperature
If superconducting microwave filters are used for switching applications, then cryogenic operation is achieved, but performance deteriorates with high return loss, limited usable bandwidth, and poor out-of-band off-state isolation
Solution Approach 1:
The patent divides the switching function into two independent SQUID devices with separate variable inductance coupling elements. This segmentation allows independent optimization of each SQUID for its specific function (one for pass-band signal routing, one for blocking), improving overall switching performance including return loss, bandwidth, and isolation while maintaining cryogenic operation
Solution Approach 2:
The patent introduces a common node as an intermediary element that couples the two SQUID devices together. This common node enables coordinated control of both SQUIDs through shared flux control mechanisms, allowing the system to achieve improved switching performance with better isolation and bandwidth while operating at cryogenic temperatures
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 provides efficient signal routing and filtering at cryogenic temperatures with improved bandwidth and reduced return loss, enabling effective integration with superconducting circuits and overcoming the limitations of conventional switches and filters.
Implementation Method 1
a first Superconducting Quantum Interference Device (SQUID) having a first variable inductance coupling element, and a second SQUID having a second variable inductance coupling element
Implementation Method 2
superconducting single-pole double-throw switch system
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
A superconducting switch system (30) is provided that includes a filter network having a first SQUID coupled to a second SQUID via a common node (36), an input port (SIGIN) coupled to the common node, a first output port (SIGOUT1) coupled to the first SQUID, and a second output port (SIGOUT2) coupled to the second SQUID. The superconducting switch system also includes a switch controller (18) configured to control an amount of induced current through the first SQUID and the second SQUID to alternately switch the first and second SQUIDS between first inductance states in which a desired bandwidth portion of a signal provided at the input terminal passes to the first output terminal and is blocked from passing to the second output terminal, and second inductance states in which the desired bandwidth portion of the input signal passes to the second output terminal and is blocked from passing to the first output terminal.