Magnetic Domain Wall Oscillator for High-Power Low-Current Output

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Solution Overview

Problem

Conventional spin torque oscillators are limited by low output power and high critical current, which results in inefficient power consumption and smaller size constraints in modern communication devices requiring higher quality factors and lower phase noise.

Innovation Solution

The design incorporates a free layer with a magnetic domain wall and a separation layer, where the free layer has perpendicular magnetic anisotropy and the fixed layer has in-plane magnetic anisotropy, allowing for increased output power and quality factor through the precession of the magnetic moment, which is induced by current or magnetic field application, and the use of laminated structures to enhance oscillation frequency and power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a conventional spin torque oscillator is used, then the device structure is compact, but the output power is low and critical current is high

Engineering Contradiction:

Improveoutput powerVSAvoidpower consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by creating a magnetic domain wall structure with specific local magnetic properties in the free layer. The domain wall region has distinct magnetic characteristics compared to the bulk material, enabling localized spin precession that generates oscillation signals with higher output power while reducing the overall critical current requirement

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The oscillator employs a composite magnetic layer structure consisting of a free layer with perpendicular magnetic anisotropy and a fixed layer with in-plane magnetic anisotropy separated by a separation layer. This composite structure combines different magnetic properties to achieve both high output power and reduced critical current, resolving the contradiction between power output and energy consumption

Inventive Principle:

Principle #40Composite materials

2Power

If the free layer has perpendicular magnetic anisotropy and fixed layer has in-plane magnetic anisotropy, then output power and quality factor increase, but device structure becomes more complex

Engineering Contradiction:

Improveoutput powerVSAvoidlayer structure complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The magnetic structure is segmented into distinct functional layers: a free layer with perpendicular magnetic anisotropy for spin precession, a separation layer for magnetic decoupling, and a fixed layer with in-plane magnetic anisotropy for field reference. This segmentation allows each layer to be optimized independently for its specific function, achieving high output power and quality factor while managing structural complexity through modular design

Inventive Principle:

Principle #1Segmentation

3Volume of moving object

If a point contact structure is used, then the oscillator is compact, but critical current is high which increases power consumption

Engineering Contradiction:

Improvedevice sizeVSAvoidpower consumption

Core Design Contradiction:

Volume of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent replaces the conventional point contact mechanical structure with a magnetic domain wall-based oscillation mechanism. Instead of relying on physical contact between magnetic moments, the system uses spin transfer torque to induce precession in a magnetic domain wall within a perpendicular magnetic anisotropy free layer. This substitution reduces the critical current requirement and power consumption while maintaining compact device dimensions

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach results in oscillators with higher output power and quality factor, reduced critical current for oscillation, and frequency tunability, addressing the limitations of conventional spin torque oscillators while enabling smaller, more efficient communication devices.

Implementation Method 1

The oscillator generates a signal by precession of a magnetic moment of the magnetic domain wall

Methodology Applied

Scientific EffectMagnetic moment precession: Precession

Implementation Method 2

A spin torque oscillator using a spin transfer torque has recently been introduced

Methodology Applied

Scientific EffectSpin transfer torque:

Data Source

PatentUS8525601B2Oscillators using magnetic domain wall and methods of operating the same

Publication Date: 2013.09.03 SAMSUNG ELECTRONICS CO LTD

AI summary

An oscillator generates a signal using precession of a magnetic moment of a magnetic domain wall. The oscillator includes a free layer having the magnetic domain wall and a fixed layer corresponding to the magnetic domain wall. A non-magnetic separation layer is interposed between the free layer and the fixed layer.