Ring-Shaped TMR Elements for Wider Linear Magnetic Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tunneling magnetoresistive (TMR)-based sensors have a limited linear output range and this limitation is exacerbated as the device width is decreased, compromising their linearity.
Innovation Solution
The use of ring-shaped TMR elements with a bridge configuration, comprising a plurality of magnetic tunneling junction (MTJ) rings, each with a free layer, barrier layer, and fixed layer, to provide improved linearity, where each MTJ ring structure has a ring shape defining an aperture and is configured to output a signal indicative of a magnetic field aligned with the fixed magnetic orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional TMR elements are used with decreased width, then device size is reduced, but linearity is compromised
Solution Approach 1:
The TMR sensor is divided into multiple TMR elements (at least two) arranged in a specific geometric configuration rather than using a single element. This segmentation allows the system to maintain small individual element sizes while achieving improved overall linearity through the collective response of multiple elements to the magnetic field.
Solution Approach 2:
The patent transitions from conventional single-element or simple bridge configurations to a multi-element geometric arrangement in space. By positioning multiple TMR elements at specific locations and orientations, the system exploits spatial dimensionality to achieve enhanced linearity that cannot be obtained by simply scaling down single elements.
2Device complexity
If conventional TMR elements are used, then device structure is simple, but linear output range is limited
Solution Approach 1:
The sensor is segmented into multiple TMR elements with distinct magnetic field sensing orientations. Each element contributes to a different component of the overall magnetic field measurement, and their combined output provides a more linear response across a wider range of magnetic field conditions compared to a single conventional TMR element.
Solution Approach 2:
The patent employs a composite structure combining multiple TMR elements with different magnetic field response characteristics. By integrating elements that respond to different magnetic field components or orientations, the system creates a composite sensing mechanism that achieves extended linear output range while maintaining reasonable structural complexity.
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 ring-shaped TMR elements exhibit enhanced linearity and sensitivity, overcoming the limitations of conventional TMR sensors by maintaining a more linear response to changes in magnetic field intensity, even at smaller widths.
Implementation Method 1
tunneling magnetoresistance (TMR) elements, which are also referred to as magnetic tunnel junction (MTJ) elements in reference to the included MTJ
Implementation Method 2
Magnetoresistance elements are another class of magnetic sensing elements that have a variable resistance that changes in response to changes in an applied or sensed magnetic field
Data Source
AI summary
Systems, circuits, and methods provide ring shaped TMR elements having increased linearity. Such ring shaped TMR elements provide transducer output responses to changes in input magnetic field levels that are more linear compared to prior TMR techniques and devices. In some embodiments, a free layer having a ring shape can create a circular magnetization resulting in a TMR element linearity that can be adjusted depending on the width of the ring shaped element. In some embodiments, such ring shaped TMR elements can overcome small diameter fabrication limits of prior art vortex elements.