Watch Bezel Antenna Layout for Touch Interface Signal Reliability

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Solution Overview

Problem

Portable electronic devices like watches face challenges in integrating an antenna with optimal length for full signal transmission/reception due to limited space and interference from metal parts, while maintaining aesthetics, energy efficiency, and manufacturing costs.

Innovation Solution

A flexible substrate with an integrated antenna circuit and touch control circuit is embedded in a dielectric and non-conductive covering element, such as a watch bezel, optimizing signal transmission and minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an antenna of optimal length is used for full signal transmission/reception, then communication reliability is improved, but the device volume increases beyond acceptable limits for portable devices like watches

Engineering Contradiction:
Improvesignal transmission/receptionVSAvoidantenna size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the physical parameters of the antenna by integrating it into a flexible substrate within the covering element, allowing the antenna to achieve optimal electrical length through strategic placement and configuration rather than physical size. The antenna circuit is designed to resonate at the required frequency within the constrained space of the watch case.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from traditional three-dimensional antenna structures to a two-dimensional planar antenna circuit printed on a flexible substrate. This dimensional reduction allows the antenna to fit within the limited surface area of the watch case while maintaining functional performance through optimized trace routing and ground plane configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If metal parts are used in the device structure, then mechanical strength is improved, but antenna performance deteriorates due to interference

Engineering Contradiction:
Improvestructural strengthVSAvoidantenna signal quality
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts the antenna circuit from proximity to metal parts by integrating it into the covering element structure, specifically positioning it in the bezel or crystal area where metal interference is minimized. This spatial separation reduces electromagnetic coupling between the antenna and metal components while maintaining overall device strength through the metal case structure.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If a touch interface is integrated into the covering element, then user interaction is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvetouch interface functionalityVSAvoidmanufacturing process
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the touch interface electrodes and the antenna circuit traces onto the same flexible substrate within the covering element. This integration allows both functions to be manufactured simultaneously using printed circuit board techniques, reducing assembly steps and manufacturing complexity compared to separate components.

Inventive Principle:
Principle #5Merging (Combining)

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 ensures efficient signal transmission/reception with minimal impact on aesthetics, energy consumption, and manufacturing costs, while avoiding interference from metal parts.

Implementation Method 1

A flexible substrate with an integrated antenna circuit and touch control circuit is embedded in a dielectric and non-conductive covering element, such as a watch bezel, optimizing signal transmission and minimizing interference.

Methodology Applied
Scientific EffectElectromagnetic isolation: Dielectric

Implementation Method 2

It is known that the optimal size of such an antenna depends directly on the wavelength of the transmitted/received signal. Indeed, an antenna of optimal length allows a signal to be sent/received in full and at full power.

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP4198653B1Portable electronic object
Publication Date: 2025.10.08 ETA SA MFG HORLOGERE SUISSE
  • EP4198653B1 patent drawingFigure 1~2
  • EP4198653B1 patent drawingFigure 3~4

AI summary

The invention relates to a portable electronic object (1) comprising a case (3) provided with a covering element (2) forming in whole or in part a touch interface of said electronic object (1), said covering element comprising a hollow body containing a substrate (5) on which are made an antenna circuit (10) of a communication module (6) of said object (1) and a touch control circuit (13) of a touch control element (8) of this object (1).