Integrated NFC Coil Layout for Frequency Isolation

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Solution Overview

Problem

Coil components used in near-field communication (NFC) often require additional electronic components like chip inductors for isolation from unnecessary frequency components, increasing the number of components and complexity.

Innovation Solution

A coil component design featuring a first coil with sub-coils connected to its ends, where the sub-coils have shorter line lengths and are positioned outside the main coil's area, without overlapping, to achieve isolation from unnecessary frequencies without additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional electronic components like chip inductors are added to ensure isolation from unnecessary frequency components, then isolation performance is improved, but the number of components increases

Engineering Contradiction:

Improveisolation performanceVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines multiple coil functions into a single integrated coil component. The first coil serves as the main antenna coil for NFC, while the second and third coils are integrated as sub-coils to provide frequency isolation. This merging eliminates the need for separate chip inductor components, reducing component count while maintaining isolation performance.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The coil component achieves multi-functionality by having the first coil serve as the primary NFC antenna while the second and third coils simultaneously provide frequency isolation. This universal design allows a single component to perform both main antenna functions and frequency filtering functions, replacing what would traditionally require multiple separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If additional electronic components are added to achieve frequency isolation, then isolation performance is improved, but device complexity increases

Engineering Contradiction:

Improveisolation performanceVSAvoidcomponent complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the frequency isolation function into the main coil structure by integrating second and third coils as sub-coils. This consolidation reduces device complexity by eliminating separate chip inductor components and their associated mounting, wiring, and assembly requirements.

Inventive Principle:

Principle #5Merging (Combining)

3Strength

If the inside area of the second coil overlaps with the inside area of the third coil, then coupling between coils increases, but isolation performance deteriorates

Engineering Contradiction:

Improvecoupling between coilsVSAvoidisolation performance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent employs asymmetric positioning where the second coil is positioned outside the inside area of the third coil, creating an asymmetric layout that minimizes magnetic coupling between the sub-coils. This asymmetric arrangement ensures that the magnetic flux paths of the second and third coils do not significantly overlap, maintaining isolation performance while still providing frequency filtering.

Inventive Principle:

Principle #4Asymmetry

4Reliability

If the line lengths of the second and third coils are increased, then isolation performance is improved, but the overall size of the coil component increases

Engineering Contradiction:

Improveisolation performanceVSAvoidcoil component size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies local quality by having the second and third coils with line lengths specifically optimized for their frequency isolation function, which are shorter than the first coil's line length optimized for NFC operation. This localized optimization allows the sub-coils to provide frequency filtering without proportionally increasing the overall component size, as their shorter lengths are sufficient for their specific isolation function.

Inventive Principle:

Principle #3Local quality

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 design ensures effective isolation from high-frequency components, maintaining impedance and reducing coupling between coils, while minimizing component count and thickness.

Implementation Method 1

a first coil (10) wound about a first coil axis (A1); a second coil (20) having one end connected to one end of the first coil (10) and wound about a second coil axis (A2); and a third coil (30) having one end connected to the other end of the first coil (10) and wound about a third coil axis (A3)

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS20250336597A1Coil component

Publication Date: 2025.10.30 TDK CORP

AI summary

Disclosed herein is a coil component that includes a first coil wound about a first coil axis, a second coil having one end connected to one end of the first coil and wound about a second coil axis, and a third coil having one end connected to the other end of the first coil and wound about a third coil axis. The line lengths of both the second and third coils are shorter than the line length of the first coil, and the inside area of the second coil and the inside area of the third coil do not overlap each other.