Bluetooth Earphone Antenna Layout to Reduce Head Absorption

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Solution Overview

Problem

Bluetooth earphones experience reduced antenna efficiency due to radiation absorption by the user's head, leading to poor antenna performance when worn.

Innovation Solution

The design includes an antenna architecture with a flexible circuit board and a specific current configuration that positions the zero radiation point of the antenna's radiation field to face the user's head, reducing the adverse effect of the head on antenna performance, and utilizing a 1/4 wavelength antenna to achieve high efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the antenna is directly worn on the user's head for convenience and miniaturization, then the Bluetooth earphone achieves portability and ease of use, but the user's head absorbs the radiation generated by the antenna, resulting in reduced antenna efficiency and poor antenna performance

Engineering Contradiction:
Improveconvenience of wearingVSAvoidantenna performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent inverts the conventional antenna current direction by using the flexible circuit board to extend the antenna current path from the earbud portion through the connecting section to the top section. This reversal positions the zero radiation point to face the user's head, converting the harmful radiation absorption into a beneficial configuration where the head is positioned at the null point of the radiation pattern.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extends the antenna structure into a new dimension by using the flexible circuit board to create a three-dimensional current path that goes from the earbud portion, through the connecting section, to the top section. This dimensional extension allows the antenna to achieve a configuration that would be impossible with a traditional planar antenna design, positioning the zero radiation point optimally relative to the user's head.

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

2Reliability

If the antenna structure is extended to achieve better radiation pattern, then the antenna efficiency is improved, but the device size and complexity increase

Engineering Contradiction:
Improveantenna efficiencyVSAvoidantenna architecture complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flexible circuit board serves multiple functions: it provides electrical connection between components, structural support for the antenna, and acts as the antenna current path itself. By making the circuit board perform the antenna function, the patent eliminates the need for a separate antenna structure, thereby improving antenna efficiency without increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the antenna function with the existing flexible circuit board structure. Instead of adding a separate antenna component, the design combines the antenna current path with the circuit board traces, creating an integrated structure that achieves better radiation pattern while maintaining simplicity in the overall device architecture.

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

This configuration significantly improves antenna efficiency and performance by minimizing radiation absorption, maintaining high efficiency even when the earphone is worn, with the antenna achieving 80% or more of its initial state efficiency.

Implementation Method 1

when an antenna of the Bluetooth earphone works, radiation generated by the earphone antenna is easily absorbed by the head of the user

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

The flexible circuit board includes a feeding part and a first extension part connected to the feeding part. The feeding part is located in the connecting section of the earphone handle portion, and is coupled to the antenna. The first extension part extends into the earbud portion.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

utilizing a 1/4 wavelength antenna to achieve high efficiency

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3923598B1Bluetooth earphone
Publication Date: 2024.03.13 HUAWEI TECH CO LTD
  • EP3923598B1 patent drawingFigure 1
  • EP3923598B1 patent drawingFigure 2~3
  • EP3923598B1 patent drawingFigure 4

AI summary

Embodiments of the present disclosure disclose a Bluetooth earphone. The Bluetooth earphone includes an earbud portion and an earphone handle portion. A receiver module is disposed in the earbud portion. The earphone handle portion includes a connecting section connected to the earbud portion, and a top section and a bottom section located on both sides of the connecting section, and a battery is disposed in the bottom section of the earphone handle portion. The Bluetooth earphone includes an antenna and a flexible circuit board. The antenna extends from the connecting section of the earphone handle portion to the top section of the earphone handle portion. The flexible circuit board includes a feeding part and a first extension part connected to the feeding part. The feeding part is located in the connecting section of the earphone handle portion, and is coupled to the antenna. The first extension part extends to the earbud portion. The Bluetooth earphone has relatively good antenna performance.