Josephson Distributed Amplifier With Reactive Delay Matching
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Solution Overview
Problem
Conventional distributed amplifiers are inefficient and inoperable with high-speed superconducting systems due to poor power matching and phasing, making it difficult to establish data links at low bit error rates in high clock rate and low signal power environments.
Innovation Solution
The solution involves forming transmission lines with superconducting elements and interposing amplification stages with resonant circuits, where the resonant circuit delay is matched to the transmission line delay to achieve wideband amplification, utilizing Josephson transmission lines and voltage sources with SQUIDs for efficient signal amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional distributed amplifier architecture is used, then wideband amplification is achieved, but amplification efficiency deteriorates due to poor power matching and phasing
Solution Approach 1:
The patent transforms the conventional resistively-terminated distributed amplifier into a reactively-terminated architecture using superconducting transmission lines and resonant circuits. By changing the termination from resistive to reactive (using resonant circuits with inductors and capacitors), the system achieves both wideband operation and improved power matching efficiency simultaneously.
Solution Approach 2:
The patent employs superconducting materials (Josephson transmission lines) combined with resonant circuits to create a composite amplification system. The superconducting transmission lines provide lossless signal propagation while the resonant circuits provide reactive termination, together achieving both wideband performance and high efficiency.
2Power
If conventional distributed amplifier is used, then amplification is achieved, but operation with high-speed superconducting systems deteriorates due to low signal power levels
Solution Approach 1:
The patent replaces conventional resistive termination with reactive termination using superconducting resonant circuits. This substitution eliminates resistive losses that degrade low-power signals, enabling reliable operation with high-speed superconducting systems at extremely low signal power levels (2-8 nW) while maintaining low bit error rates.
Solution Approach 2:
The patent changes the operating parameters by using superconducting transmission lines with reactive termination instead of conventional resistive termination. This parameter change enables the system to handle extremely low signal power levels reliably, making it suitable for high-speed superconducting digital circuits operating at 10-40 GHz.
3Productivity
If resonant circuit delay is matched with transmission line delay, then wideband amplification efficiency is improved, but device complexity increases
Solution Approach 1:
The patent divides the amplification system into discrete stages, each consisting of a superconducting transmission line segment and a resonant circuit. By segmenting the system into repeatable modular units with matched delays, the patent achieves wideband amplification efficiency while managing complexity through standardization and modularity.
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 enhances amplification efficiency, achieving higher bandwidth-gain products and supporting high-throughput data amplification with low signal power, particularly in superconducting systems operating at high clock rates.
Implementation Method 1
each of the first transmission line and the second transmission line having a plurality of superconducting transmission elements, each JTL having a Josephson transmission delay
Implementation Method 2
each amplification stage having an resonant circuit with a resonant circuit delay; wherein the resonant transmission delay is substantially matched to the Josephson transmission delay
Data Source
AI summary
The disclosure generally relates to a method and apparatus for providing high-speed, low signal power amplification. In an exemplary embodiment, the disclosure relates to a method for providing a wideband amplification of a signal by forming a first transmission line in parallel with a second transmission line, each of the first transmission line and the second transmission line having a plurality of superconducting transmission elements, each transmission line having a transmission line delay; interposing a plurality of amplification stages between the first transmission line and the second transmission line, each amplification stage having an resonant circuit with a resonant circuit delay; and substantially matching the resonant circuit delay for at least one of the plurality of amplification stages with the transmission line delay of at least one of the superconducting transmission lines.