Phase-Shifted Magnetometry Adaptive Cancellation

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Solution Overview

Problem

Advanced magnetic detection systems are limited by their operation in specific conditions such as high vacuum and cryogenic temperatures, and existing small size, weight, and power (SWAP) magnetic sensors lack sensitivity, vector accuracy, and bandwidth for ambient condition applications.

Innovation Solution

A magnetic detection system utilizing a magneto-optical defect center material with a RF and optical excitation source, applying phase-shifted pulse sequences to compute a combined magnetometry curve for precise magnetic field measurement, reducing vertical noise and enhancing dynamic range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If advanced magnetic detection systems are designed for high sensitivity and accuracy, then measurement precision is improved, but the systems require operation in high vacuum and cryogenic temperatures, reducing adaptability

Engineering Contradiction:

Improvemagnetic field detection accuracyVSAvoidoperating condition flexibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the operating parameters of the magnetic detection system by using defect centers in wide bandgap semiconductors that operate at ambient temperatures and pressures, rather than requiring cryogenic temperatures and high vacuum conditions. This parameter change enables the system to maintain high measurement precision while significantly improving adaptability to different operating environments.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If small size, weight, and power magnetic sensors are used, then device complexity is reduced, but sensitivity, vector accuracy, and bandwidth are insufficient

Engineering Contradiction:

Improvesensor system simplicityVSAvoidmagnetic field detection sensitivity

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces traditional mechanical or electronic magnetic sensor systems with an optically detected magnetic resonance system using defect centers. This substitution uses optical excitation and detection methods instead of conventional electromagnetic approaches, achieving high sensitivity and bandwidth while maintaining simple device structure and ambient operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs composite material structures combining wide bandgap semiconductors with specific defect centers (such as nitrogen-vacancy centers in diamond or similar defects in silicon carbide). These composite material systems provide both the simplicity of solid-state devices and the high sensitivity required for precise magnetic field detection.

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If phase shifted pulse sequences are applied, then noise is reduced and dynamic range is increased, but the system complexity increases

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidpulse sequence control complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies periodic pulse sequences with specific phase shifts to the defect centers, using oscillating electromagnetic fields at resonant frequencies. This periodic action enables noise reduction through signal averaging and dynamic range expansion while maintaining relatively simple control electronics that can generate standard RF and microwave pulses.

Inventive Principle:

Principle #19Periodic action

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 system effectively detects external magnetic fields with improved sensitivity and accuracy, capable of operating in ambient conditions by reducing noise and increasing dynamic range through adaptive phase control.

Implementation Method 1

a magneto-optical defect center material comprising a plurality of magneto-optical defect centers; a radio frequency (RF) excitation source configured to provide RF excitations to the magneto-optical defect center material; an optical excitation source configured to provide optical excitation to the magneto-optical defect center material

Methodology Applied

Scientific EffectMagneto-optical effect: Magneto-Optic Effects

Implementation Method 2

optical signals emitted by the magneto-optical defect center material due to the second and fourth optical excitation pulses are fluorescence signals

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS10816616B2Phase shifted magnetometry adaptive cancellation

Publication Date: 2020.10.27 LOCKHEED MARTIN CORP

AI summary

A system for magnetic detection of an external magnetic field is described. The system includes a controller configured to control components of the system. The controller is configured to control an optical excitation source and a RF excitation source to apply pulse sequences to a magneto-optical defect center material such that in the excitation pulses of a first pair of RF excitation pulses have a first phase difference, the excitation pulses of a second pair of RF excitation pulses have a second phase difference, and the second phase difference is different from the first phase difference. The controller computes a combined magnetometry curve as a function of the RF excitation frequency based on a difference between a measured value of a first light detection signal and a measured value of a second light detection signal. The controller sets the first phase difference and the second phase difference based on the combined magnetometry curve.