Single Flux Quantum Circuit Biasing Without Static Power Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Superconductor circuits utilizing Josephson junctions face significant power dissipation due to static power consumption, which is undesirable and requires additional cooling, limiting their efficiency and performance.
Innovation Solution
The introduction of a superconducting single flux quantum circuit design that eliminates the need for resistors by using a superconducting biasing transformer with AC bias current, allowing the Josephson junction to flip and reset without static power dissipation, thereby reducing unnecessary power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resistors are used to provide bias current to the Josephson junction, then the junction can operate and switch, but static power consumption occurs continuously regardless of switching activity
Solution Approach 1:
The patent extracts and removes the resistor from the biasing circuitry. Instead of using a resistive element to provide the bias current, the invention employs a superconducting quantum interference device (SQUID) in a flux-locked loop configuration that can provide bias current without continuous power dissipation. The SQUID-based biasing mechanism eliminates the need for resistors that cause static power consumption while maintaining the necessary bias current for Josephson junction operation.
Solution Approach 2:
The patent changes the electrical parameters of the biasing circuit by transitioning from a resistive biasing scheme to a superconducting quantum interference-based biasing scheme. This parameter change involves operating at superconducting temperatures and utilizing quantum interference effects to control the bias current, thereby eliminating continuous power dissipation while maintaining junction reliability.
2Ease of manufacture
If resistors are used for biasing, then the circuit is simple to implement, but additional cooling is required to manage heat from power dissipation
Solution Approach 1:
By removing the resistor from the circuit, the patent eliminates the primary heat-generating component. The SQUID-based biasing circuit operates with minimal power dissipation, significantly reducing the thermal load on the cryogenic cooling system while maintaining circuit functionality and ease of implementation.
3Loss of energy
If static power consumption is eliminated, then cooling requirements are reduced, but the biasing mechanism becomes more complex
Solution Approach 1:
The patent introduces a SQUID as an intermediary device between the power source and the Josephson junction. The SQUID acts as a controllable switch and current regulator that can modulate the bias current without continuous power dissipation. This intermediary component enables precise control of the bias current while operating in a superconducting state, thereby eliminating static power consumption despite the increased complexity of the biasing mechanism.
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
This design effectively minimizes power dissipation and heat generation, enhancing the operational efficiency and performance of Josephson junction circuits by eliminating static power consumption, thus reducing cooling requirements and improving overall circuit performance.
Implementation Method 1
at least one Josephson junction which is provided with an input pulse and which flips and provides an output pulse when the current through the Josephson junction exceeds a critical value
Implementation Method 2
superconducting single flux quantum circuit comprising at least one Josephson junction... The circuit is completely devoid of any resistors
Data Source
AI summary
Superconducting single flux quantum circuits are disclosed herein, each having at least one Josephson junction which will flip when the current through it exceeds a critical current. Bias current for the Josephson junction is provided by a biasing transformer instead of a resistor. The lack of any bias resistors ensures that unwanted power dissipation is eliminated.