Magnetometric Sensor Feedback Circuit for Linear Wideband Detection

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Solution Overview

Problem

Current magnetometric sensors have limited frequency range and non-linear response to magnetic fields, restricting their bandwidth and sensitivity, especially at room temperature and low temperatures for superconducting sensors.

Innovation Solution

A magnetometric sensor design incorporating a superconducting magnetic sensor, a control circuit, and a conductive wire that generates a feedback current to compensate for external magnetic flux, allowing for a linear measurement of the magnetic field and expanding the sensor's bandwidth by optimizing the circuit's dimensions and configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the bandwidth of magnetometric sensors is widened by optimizing the impedance of the measurement circuit, then the frequency range is improved, but the measurement precision and linearity deteriorate

Engineering Contradiction:
Improvefrequency rangeVSAvoidmeasurement linearity
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements a feedback circuit that generates a counter-reaction magnetic field to compensate for the external magnetic flux in real-time. This feedback mechanism maintains measurement linearity across a wide frequency range by actively correcting the sensor response, resolving the contradiction between bandwidth expansion and measurement precision preservation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent optimizes specific parameters including the impedance of the measurement circuit, the dimensions of the superconducting sensor, and the configuration of the feedback circuit. By carefully adjusting these parameters, the system achieves both wide bandwidth and high measurement linearity simultaneously

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If superconducting materials are used to achieve highest sensitivity, then the measurement precision is improved, but the device complexity and operating conditions worsen

Engineering Contradiction:
Improvemagnetic field sensitivityVSAvoidoperating temperature requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces conventional magnetic sensing mechanisms with superconducting quantum interference devices (SQUIDs) and superconducting quantum interference filters (SQIFs). These superconducting components provide extremely high magnetic field sensitivity while integrating directly with the feedback circuit, achieving the desired precision without requiring complex mechanical or optical systems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs composite structures combining superconducting materials with conventional conductive materials in the feedback circuit. This composite approach leverages the high sensitivity of superconductors while using conventional materials for signal processing and control functions, managing the overall system complexity

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If the linear response region is expanded for superconducting sensors, then the measurement precision is improved, but the bandwidth deteriorates

Engineering Contradiction:
Improvelinear response rangeVSAvoidbandwidth
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The feedback circuit continuously monitors the sensor output and generates a compensating signal to maintain operation within the linear response region. This active control enables the system to achieve both an expanded effective linear range and wide bandwidth by dynamically adjusting the operating point

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces dynamic control through the feedback circuit that adapts to changing magnetic field conditions. This dynamic adjustment allows the system to maintain linear response characteristics across a broader frequency spectrum, resolving the trade-off between linear range and bandwidth

Inventive Principle:
Principle #15Dynamics

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 design achieves a wide bandwidth from very low to ultra-high frequencies with a linear response to magnetic fields, enhancing sensitivity and allowing for high-density integration and detection of magnetic fields across a broad range.

Implementation Method 1

a magnetic sensor (12) having a surface and generating a response signal when it is immersed in an external magnetic field creating an external flux through said surface

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

the wire being traversed by the feedback current, the circuit and the conducting wire being such that a feedback magnetic field is created whose counter-reaction flux through the surface of the magnetic sensor substantially compensates, at each instant, the external flux

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

such a magnetic sensor, using superconducting materials, operates at low temperatures, around approximately 80 K, for so-called high critical temperature superconducting materials

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentEP3149504B1Magnetometric sensor
Publication Date: 2018.08.29 THALES SA
  • EP3149504B1 patent drawingFigure 1~3
  • EP3149504B1 patent drawing

AI summary

The invention relates to a sensor (10) which includes a magnetic sensor (12) generating a response signal (V) when plunged into an external magnetic field (Bext) creating an external flux (φext) through said sensor. Said sensor includes: a control circuit (14) taking the response signal from the sensor as input and generating a feedback current (iCR) as output; and a conductive wire (16) arranged in the vicinity of the sensor and connected to the output of the control circuit, the wire having the feedback current passing therethrough, the circuit and the conductive wire being such that a magnetic feedback field (BCR) is created in which the flux through the sensor substantially compensates for the external flux at each instant, an output signal of the sensor being made up of the feedback current.