Wearable Antenna Using Body Coupling for Stable Miniaturization
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Solution Overview
Problem
Conventional wireless wearable devices face challenges in miniaturization due to the size limitations of antennas, which are typically required to be at least a quarter of a wavelength for effective wireless communication, and the instability of wireless signals when the device is held by the user, as the gripping position can change, affecting signal quality.
Innovation Solution
The integration of a first electrode within a wireless wearable device that forms an antenna with the human body, allowing the antenna to be significantly shorter than a quarter wavelength, and maintaining constant contact with the body for stable signal transmission and reception, enabling communication across various protocols like Bluetooth, Wi-Fi, and GPS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional antenna is used in wireless wearable devices, then wireless communication can be achieved, but the device size increases due to the quarter-wavelength requirement
Solution Approach 1:
The patent merges the antenna function with the human body by using the body as part of the antenna structure. The first electrode is configured to contact the user's body, and together they form a capacitive antenna system that eliminates the need for a separate quarter-wavelength antenna, thereby reducing device size while maintaining wireless communication capability
Solution Approach 2:
The patent introduces a capacitor structure as an intermediary between the first electrode and the user's body. This capacitor enhances the coupling effect and improves the antenna performance, allowing the system to achieve reliable wireless signal transmission with a much smaller electrode structure than conventional antennas
2Ease of operation
If the gripping position changes, then the device is more adaptable to user comfort, but the wireless signal stability deteriorates
Solution Approach 1:
The patent makes the human body serve multiple functions: it acts as both the antenna element for wireless communication and the mounting structure for the device. This universal use of the body ensures that signal stability is maintained regardless of gripping position changes, as the body naturally provides a consistent reference plane
Solution Approach 2:
The system uses the user's own body as the antenna, meaning the antenna structure adapts automatically to different user anatomies and gripping positions. The body's natural contours and electrical properties provide self-adjusting signal characteristics that maintain stability across different usage scenarios
3Volume of moving object
If the first electrode length is reduced for miniaturization, then device compactness improves, but antenna effectiveness deteriorates
Solution Approach 1:
The patent changes the fundamental parameter of antenna length by using the human body as the extending element. The first electrode only needs to be a small component that interfaces with the body, and the body itself provides the necessary electrical length for effective radiation, allowing extreme miniaturization of the wearable device
Solution Approach 2:
The patent replaces the mechanical antenna structure (physical quarter-wavelength conductor) with an electrical field-based capacitive antenna system. The capacitor and body interface create an effective radiating structure through electrical field coupling rather than relying on a long physical conductor
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 solution allows for a compact device design with improved signal quality and stability, as the human body acts as a part of the antenna, reducing the length of the first electrode and maintaining consistent contact, thereby enhancing the wearable device's performance and usability.
Implementation Method 1
The antenna module is configured to transmit and receive a wireless signal. A part of a body of a user and the first electrode together serve as an antenna for the wireless signal.
Implementation Method 2
the PCB is configured to detect a change in capacitance between the part of the housing and the first electrode to determine an operation performed by a user on the housing
Data Source
AI summary
A wireless wearable device, including a housing, a PCB located inside the housing, and an antenna module connected to the PCB. The antenna module is configured to transmit and receive a wireless signal, and includes a first electrode. A part of a body of a user and the first electrode together serve as an antenna for the wireless signal. A total length of the first electrode can be lower than a quarter of a wavelength applied in wireless communication. The user does not need to perform an intentional touch or grip due to a constant contact in wearing. Miniaturization of the whole device is achieved while ensuring good quality of wireless communication.