SFQ Logic Biasing Circuit Without Feeding JTLs
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Solution Overview
Problem
Existing SFQ logic circuits face challenges with high power dissipation and significant circuit area requirements due to the use of feeding Josephson Transmission Lines (JTL) and dropping resistors, which complicate biasing and increase power consumption.
Innovation Solution
Replace the feeding JTL with resistors to ground and utilize Josephson junctions as current sources to reduce power dissipation and eliminate unnecessary components, thereby optimizing circuit area and power distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a feeding Josephson Transmission Line (JTL) is used to implement on-chip voltage regulation, then the bias voltage can be kept very low (tens of microvolts) to reduce power dissipation, but the feeding JTL itself requires significant operating current and contributes substantially to circuit area requirement and component count
Solution Approach 1:
The patent extracts and removes the feeding JTL from the circuit architecture, replacing it with a simplified biasing approach using only resistors to ground. This eliminates the component that was consuming significant current and occupying substantial circuit area, while maintaining the low power dissipation benefit through alternative means.
Solution Approach 2:
The patent replaces the complex, current-intensive feeding JTL with simple resistors to ground, which are much less resource-intensive components. This substitution uses inexpensive, low-area components to achieve the same biasing function without the drawbacks of the original feeding JTL approach.
2Loss of energy
If a feeding Josephson Transmission Line (JTL) is used to implement on-chip voltage regulation, then the bias voltage can be kept very low (tens of microvolts) to reduce power dissipation, but the feeding JTL requires significant operating current
Solution Approach 1:
The patent extracts and removes the feeding JTL from the circuit architecture, replacing it with a simplified biasing approach using only resistors to ground. This eliminates the component that was consuming significant current and occupying substantial circuit area, while maintaining the low power dissipation benefit through alternative means.
3Ease of operation
If dropping resistors are used in SFQ logic circuits, then the circuits can be biased with direct current, but the resistors contribute to power dissipation and increase circuit area
Solution Approach 1:
The patent removes the dropping resistors from the circuit architecture and replaces them with a direct resistor-to-ground biasing approach. This elimination of intermediate components reduces the overall power dissipation and circuit area while maintaining DC biasing capability.
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 approach significantly reduces power dissipation by up to 90% and frees up substantial circuit area, allowing for more efficient and compact SFQ logic circuits.
Implementation Method 1
A flux quantum, proportional to the magnetic flux through the SQUID, is injected into a transmission line by a Josephson junction in response to a current step.
Data Source
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AI summary
Disclosed herein are embodiments including electrical structures that includes a first cell, a first inductor, a first resistor, and a first shunted Josephson junction. The first inductor is connected in series with the first shunted Josephson junction at a first terminal end of the first inductor and a second terminal end of the first inductor is connected to a feed point of the first cell being powered. A first end of the first resistor having connected to ground and a second end being connected to the first shunted Josephson junction at a terminal of the first shunted Josephson junction that is not connected to the first inductor. A source of an electrical current source that is external to the first cell is connected to the first shunted junction and the first resistor at a common point.