Dual RF Element NV Diamond Sensor for Uniform Microwave Fields

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Solution Overview

Problem

Magnetic sensor systems using nitrogen vacancy (NV) centers in diamond face challenges in achieving uniform microwave signals across the NV centers, which affects sensitivity and accuracy, and struggle with large bandwidth generation due to the small size of RF antenna elements, also blocking light and limiting light access to the diamond.

Innovation Solution

The implementation of dual radio frequency (RF) elements with stacked spiral antenna coils provides a uniform microwave signal over the NV diamond, allowing greater light access and increasing efficiency by using all edges and faces of the diamond for light input and egress, and can be fed by a single or separate RF feeds for enhanced operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single RF element is used, then the device complexity is reduced, but the uniformity of microwave signal over the NV diamond deteriorates

Engineering Contradiction:

ImproveRF element configurationVSAvoidmicrowave signal uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent divides the RF excitation system into two separate RF elements (first RF element and second RF element) that are positioned on opposite sides of the NV diamond. Each RF element generates a microwave signal that contributes to the overall uniformity of the magnetic field across the diamond, resolving the contradiction between simple configuration and signal uniformity.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If RF antenna elements are made small, then the bandwidth generation is improved, but the light access to the diamond is blocked

Engineering Contradiction:

Improvebandwidth generationVSAvoidlight access to diamond

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent transitions from a planar arrangement where RF elements block light paths to a three-dimensional configuration where RF elements are positioned on opposite faces of the diamond. This spatial arrangement allows light to access the diamond from directions not blocked by the compact RF elements, resolving the contradiction between bandwidth generation and light access.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If dual RF elements are used, then the uniformity of microwave signal is improved, but the device complexity increases

Engineering Contradiction:

Improvemicrowave signal uniformityVSAvoidRF element configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the outputs of two RF elements to create a unified microwave signal field across the NV diamond. By coordinating the operation of both RF elements through RF feed cables, the system achieves enhanced signal uniformity while managing the complexity through integrated feeding mechanisms.

Inventive Principle:

Principle #5Merging (Combining)

4Productivity

If light access to diamond is increased, then the sensor efficiency is improved, but the RF element design becomes more constrained

Engineering Contradiction:

Improvesensor efficiencyVSAvoidRF element design constraints

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent employs asymmetric positioning of RF elements on opposite faces of the diamond, allowing optimized light paths through edges and other faces while maintaining effective RF coupling. This asymmetric arrangement enables improved light access for sensor efficiency while managing RF element design constraints through strategic positioning.

Inventive Principle:

Principle #4Asymmetry

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 dual RF element arrangement enhances the sensitivity and accuracy of NV diamond magnetic sensors by ensuring a uniform RF field and increased light collection, improving the overall efficiency of the sensor system.

Implementation Method 1

Magnetic sensors based on a nitrogen vacancy (NV) center in diamond are known. Diamond NV (DNV) sensors may provide good sensitivity for magnetic field measurements.

Methodology Applied

Scientific EffectNitrogen-vacancy center spin resonance: Electron Paramagnetic Resonance

Implementation Method 2

The first RF element and the second RF element generate a microwave signal that is uniform over the NV center diamond.

Methodology Applied

Scientific EffectElectromagnetic radiation generation: Electromagnetic Induction

Data Source

PatentUS10520558B2Diamond nitrogen vacancy sensor with nitrogen-vacancy center diamond located between dual RF sources

Publication Date: 2019.12.31 LOCKHEED MARTIN CORP

AI summary

A magnetic field sensor assembly includes a first radio frequency (RF) element; a second RF element; an RF feed cable operably connected to the first RF element and the second RF element that provides an RF signal to the first RF element and the second RF element; and a magneto-optical defect center material located between the first RF element and the second RF element. The first RF element and the second RF element generate a microwave signal that is uniform over the magneto-optical defect center material. The magneto-optical defect center material may be a nitrogen-vacancy center diamond.