Flexible Cylindrical RFID Antenna With Omnidirectional 3D Read Range

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current RFID/NFC antennas for cylindrical bodies are challenging to fabricate and tune for 3D responses, especially when the object is in arbitrary positions or moving, requiring complex combinations of orthogonal antennas and often necessitating custom ASICs, which is complicated by the cylindrical shape of batteries.

Innovation Solution

A single omni-directional antenna is designed for cylindrical bodies, featuring two symmetrical loop antennas with out-of-phase or in-phase configurations printed on a flexible substrate that can be wrapped around the body, incorporating an EMF deflector to prevent Eddy currents and enhance signal communication, allowing for consistent read ranges regardless of orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two orthogonal antennas are used to achieve 3D response, then the spatial coverage is improved, but the device complexity and fabrication difficulty increase

Engineering Contradiction:

Improvespatial responseVSAvoidantenna combination

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines two orthogonal loop antennas into a single integrated antenna structure that provides omnidirectional 3D response. The antenna consists of a first loop in a first plane and a second loop in a second plane perpendicular to the first plane, both sharing a common axis. This merging eliminates the need for separate orthogonal antenna assemblies while maintaining 3D spatial coverage capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated antenna structure serves multiple functions simultaneously: it provides RFID/NFC communication in all spatial directions (omnidirectional), maintains resonance at the required frequency, and eliminates the need for custom ASIC design. The single antenna structure replaces what would otherwise require multiple separate antenna components and complex matching circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If custom ASIC is used to tune orthogonal antennas, then the performance is improved, but the manufacturing cost and complexity increase

Engineering Contradiction:

Improveantenna tuningVSAvoidcustom ASIC

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses standard, off-the-shelf RFID/NFC chips that can be directly integrated with the antenna structure, eliminating the need for expensive custom ASIC design and fabrication. The antenna is designed to work with commercially available chips, reducing both development cost and manufacturing complexity while maintaining adequate performance for typical applications.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If antenna is placed on cylindrical body, then the application versatility is improved, but the fabrication and tuning difficulty increase

Engineering Contradiction:

Improvecylindrical body compatibilityVSAvoidantenna fabrication

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent designs the antenna specifically for curved surfaces, particularly cylindrical bodies like batteries. The antenna structure can be wrapped around or conformally printed on cylindrical surfaces, maintaining its electromagnetic performance. The loop structure is configured to accommodate the curvature of the cylindrical body while preserving the orthogonal plane relationship between the two loops.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Adaptability or versatility

If flexible substrate is used to wrap around cylindrical body, then the adaptability is improved, but the Eddy current interference increases

Engineering Contradiction:

Improvecylindrical body placementVSAvoidEddy current

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an electromagnetic field (EMF) deflector as an intermediary layer between the conductive cylindrical body (battery) and the antenna substrate. This deflector prevents Eddy currents from forming in the conductive body when exposed to the antenna's electromagnetic field, thereby eliminating signal interference and heating issues while allowing the flexible substrate to maintain close proximity to the cylindrical surface for optimal coupling.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution provides a consistent and efficient 3D read range of 20-35 mm around a cylindrical body, improving signal fidelity and simplifying the integration with RFID/NFC chips, eliminating the need for custom ASICs and enabling flexible placement on conductive materials.

Implementation Method 1

incorporating an EMF deflector to prevent Eddy currents and enhance signal communication

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP3000152B1Omni-directional antenna for a cylindrical body

Publication Date: 2023.12.27 DURACELL US OPERATIONS INC

Figure 1
Figure 2A~2B
Figure 3A~3B

AI summary

An antenna for a cylindrical body may include a flexible substrate with the antenna on it with a first terminal and a second terminal electrically connected to an integrated circuit, the flexible substrate coupled to the cylindrical body.