Nano-Scale Spectrum Sensor Using Magnetic Tunnel Junctions

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Solution Overview

Problem

Current spectrum sensing technologies in cognitive radio systems, such as scanning spectrometers and FFT-based sensors, have high power consumption and complexity, making them costly and inefficient for monitoring electromagnetic radiation spectrum usage.

Innovation Solution

A nano-scale spectrum sensor system using magnetic tunnel junctions and spin torque oscillators, coupled with a graphene frequency multiplier, that can be electromagnetically excited at predetermined frequencies to determine ambient electromagnetic radiation spectrum usage, reducing the need for computationally intensive operations and enhancing frequency resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If scanning spectrometers or FFT-based sensors are used for spectrum sensing, then spectrum usage can be monitored, but power consumption and device complexity increase

Engineering Contradiction:
Improvespectrum sensing capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces traditional mechanical/electronic scanning spectrometers and FFT-based digital signal processing systems with a magnetic resonance-based sensing system. The system uses nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) principles where ambient radio frequency signals excite nuclear spins in a sample, and the resulting relaxation signals are detected by a magnetic resonance detector. This substitution eliminates the need for high-power scanning mechanisms and complex digital processing, achieving spectrum sensing with significantly reduced power consumption while maintaining reliable detection capability.

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

Solution Approach 2:

The patent introduces a magnetic resonance detector as an intermediary component that translates ambient radio frequency spectrum usage into detectable magnetic resonance signals. The detector acts as a mediator between the ambient electromagnetic environment and the sensing system, converting RF signals at specific frequencies into nuclear spin excitations that produce measurable relaxation signals. This intermediary approach enables selective frequency monitoring without requiring the sensing system to directly process wideband RF signals, thereby reducing power consumption and complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If scanning spectrometers or FFT-based sensors are used for spectrum sensing, then spectrum usage can be monitored, but device complexity and cost increase

Engineering Contradiction:
Improvespectrum sensing capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex scanning spectrometer hardware and FFT-based digital signal processing systems with a magnetic resonance-based sensing system. The system uses nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) principles where ambient radio frequency signals excite nuclear spins in a sample, and the resulting relaxation signals are detected by a magnetic resonance detector. This substitution eliminates the need for high-power scanning mechanisms and complex digital processing, achieving spectrum sensing with significantly reduced power consumption while maintaining reliable detection capability.

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

Solution Approach 2:

The patent introduces a magnetic resonance detector as an intermediary component that translates ambient radio frequency spectrum usage into detectable magnetic resonance signals. The detector acts as a mediator between the ambient electromagnetic environment and the sensing system, converting RF signals at specific frequencies into nuclear spin excitations that produce measurable relaxation signals. This intermediary approach enables selective frequency monitoring without requiring the sensing system to directly process wideband RF signals, thereby reducing power consumption and complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If traditional spectrum sensing methods are used, then broad spectrum coverage can be achieved, but frequency resolution and power efficiency decrease

Engineering Contradiction:
Improvespectrum coverageVSAvoidfrequency resolution
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent employs dynamic frequency tuning capability in the magnetic resonance detector, allowing the system to adjust its resonant frequency to match different target frequencies in the ambient spectrum. By tuning the detector's Larmor frequency or resonance conditions, the system can selectively monitor specific frequency bands with high precision. This dynamic adaptation enables the system to achieve both broad spectrum coverage (by tuning to different frequencies) and high frequency resolution (by focusing on specific tuned frequencies), resolving the contradiction between versatility and measurement precision.

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

This solution enables low-power, selective frequency monitoring of ambient spectrum usage, reducing power consumption and complexity while improving frequency resolution and accuracy, allowing for efficient identification of available channels in cognitive radio systems.

Implementation Method 1

The nano-scale spectrum sensor may comprise one or more magnetic tunnel junctions

Methodology Applied
Scientific EffectMagnetic tunneling:

Implementation Method 2

The spin torque oscillators may be physically and/or electromagnetically tuned to different respective predetermined frequencies

Methodology Applied
Scientific EffectSpin-transfer torque:

Implementation Method 3

The graphene frequency multiplier configured to multiply the frequency of one or more portions of received ambient electromagnetic radiation

Methodology Applied
Scientific EffectFrequency multiplication:

Data Source

PatentEP2633565B1An apparatus for spectrum sensing and associated methods
Publication Date: 2021.08.04 NOKIA TECHNOLOGIES OY
  • EP2633565B1 patent drawingFigure 1A~1C
  • EP2633565B1 patent drawingFigure 2~3
  • EP2633565B1 patent drawingFigure 4~6

AI summary

In one embodiment, an apparatus comprises a nano-scale spectrum sensor configured to be electromagnetically excitable at a predetermined frequency based on received ambient electromagnetic radiation. The apparatus is also configured to be able to use this excitation of the nano-scale spectrum sensor to thereby determine ambient electromagnetic radiation spectrum usage.