Cryogenic RF Shield Layout for Electromagnetic and Thermal Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Superconductor-based quantum sensors are prone to performance degradation due to electromagnetic and thermal noise when used outside tightly controlled conditions, necessitating improved cryogenic RF devices with enhanced noise mitigation.
Innovation Solution
A cryogenic RF device comprising a cryogenic enclosure, cryocooler, sensor, electromagnetic shield, and thermal shield, which maintains a high-vacuum environment and employs passive shielding techniques to attenuate electromagnetic and thermal noise, isolating the electromagnetic shield from internal chamber walls and using grounded conductors to displace noise to a ground source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the sensor is exposed to electromagnetic spectrum for detection, then the sensor can detect electromagnetic signals, but electromagnetic noise degrades sensor performance
Solution Approach 1:
The device is segmented into distinct functional zones: a vacuum chamber housing the sensor and electromagnetic shield, separated from the external environment. The electromagnetic shield creates an isolated electromagnetic environment within the vacuum chamber, allowing the sensor to detect external signals while being protected from noise
Solution Approach 2:
The electromagnetic shield acts as an intermediary between the sensor and external electromagnetic environment. It selectively allows desired RF signals to reach the sensor while blocking harmful electromagnetic noise, serving as a mediator that filters the electromagnetic environment
2Measurement precision
If the sensor is cooled to cryogenic temperatures to exploit quantum phenomena, then quantum effects are enhanced, but thermal noise from the environment degrades performance
Solution Approach 1:
The sensor is extracted from the thermal environment by extending the cold-finger through the vacuum chamber to place the sensor outside the chamber in the cryogenic zone. This physical extraction removes the sensor from the thermal noise source while maintaining quantum effect exploitation
Solution Approach 2:
The sensor is nested at the tip of the cold-finger, which itself is nested within the vacuum chamber structure. This nested arrangement allows the sensor to be positioned in the cryogenic environment while being supported by the chamber structure, isolating it from thermal noise
3Object-affected harmful factors
If electromagnetic shielding is implemented to block noise, then electromagnetic interference is reduced, but thermal coupling between shield and chamber walls increases
Solution Approach 1:
The thermal shield acts as a thermal intermediary between the electromagnetic shield and the vacuum chamber walls. It provides thermal isolation while allowing the electromagnetic shield to maintain its shielding function, mediating between electromagnetic and thermal requirements
Solution Approach 2:
The thermal shield is implemented as a thin insulating barrier that provides thermal isolation without significant mass. This thin film approach blocks thermal conduction paths while minimizing the shield's thermal mass and its coupling to the chamber walls
4Reliability
If the sensor is placed inside the vacuum chamber for protection, then environmental protection is improved, but electromagnetic shielding becomes less effective
Solution Approach 1:
The device is segmented into protected components (sensor at cold-finger tip outside chamber) and shielded components (electromagnetic and thermal shields inside chamber). This segmentation allows the sensor to be protected from the environment while maintaining electromagnetic transparency
Solution Approach 2:
The electromagnetic shield is designed with local quality variations: it is substantially transparent to desired RF signals in the direction of the sensor while blocking electromagnetic noise from other directions. The shield's properties are optimized locally to allow sensor functionality while providing protection
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 device achieves improved performance by reducing electromagnetic coupling and thermal effects, creating a robust environment for high sensitivity RF devices by minimizing noise and heat interference.
Implementation Method 1
The cryocooler cold-finger is disposed within the cryogenic enclosure such that the cold-finger extends through the vacuum chamber and a tip of the cold-finger is disposed within the radome. The sensor is disposed on the tip of the cold-finger.
Implementation Method 2
The electromagnetic shield is disposed within the vacuum chamber so as to shield the electronic circuitry, but not the sensor, from external electromagnetic radiation.
Implementation Method 3
The thermal shield is disposed within the vacuum chamber so as to electrically isolate the electromagnetic shield from vacuum chamber walls.
Implementation Method 4
a cryogenic enclosure... capable of maintaining an internal high-vacuum cryogenic environment
Data Source
AI summary
A cryogenic RF device comprising: a cryogenic enclosure, a cryocooler cold-finger, a sensor, an electromagnetic shield, and a thermal shield. The cryogenic enclosure is capable of maintaining an internal high-vacuum cryogenic environment and includes a radome and a vacuum chamber. The radome is, and the vacuum chamber is not, substantially transparent to desired RF signals. The sensor is disposed on the tip of the cold-finger in the radome. The electromagnetic shield is disposed within the vacuum chamber so as to shield electronic circuitry, but not the sensor, from external electromagnetic radiation. The thermal shield is disposed within the vacuum chamber so as to electrically isolate the electromagnetic shield from vacuum chamber walls. The electromagnetic shield and the thermal shield are electrically- and thermally-isolated from the cold-finger. The electromagnetic shield is electrically connected to at least one grounded electrical conductor that passes through an electrically-isolated feedthrough on the vacuum chamber.