Wearable Body Sensor Antenna Ground Layer Reflection
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Solution Overview
Problem
Current wearable body sensors lack efficient RF signal radiation and absorption mechanisms, leading to suboptimal performance in monitoring biosignals such as electrocardiogram, electromyogram, body temperature, and vital signs, especially when worn on the body.
Innovation Solution
A wearable body sensor design incorporating a conductive electrode, a main board with an RF communication circuit, an antenna with a vertical feeding structure, and a ground layer to reflect RF signals, along with electrical elements like through-hole vias for connecting components, enhances RF signal radiation and absorption efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an antenna is used to radiate RF signals in wearable body sensors, then wireless communication capability is achieved, but RF signals are absorbed by the body leading to reduced radiation efficiency
Solution Approach 1:
A ground layer is introduced as an intermediary component between the antenna and the human body. This ground layer acts as a mediator that reflects RF signals away from the body, preventing direct absorption. The ground layer is electrically connected to the antenna through vias, creating a reflective surface that redirects RF energy without requiring the signal to penetrate the body tissues, thereby reducing energy loss while maintaining wireless communication functionality.
2Reliability
If a ground layer is added to reflect RF signals, then radiation efficiency is improved, but device complexity increases
Solution Approach 1:
The ground layer is implemented as a thin conductive film or patterned conductive layer integrated into the wearable sensor structure. This thin-film approach provides the necessary RF reflection capability while minimizing the additional thickness and structural complexity. The ground layer can be patterned using standard PCB techniques or flexible circuit manufacturing, allowing it to be integrated without significantly complicating the overall device architecture.
Solution Approach 2:
The ground layer is electrically connected to the antenna through vias that are integrated during the same manufacturing process as the antenna itself. The ground layer serves multiple functions: it provides RF signal reflection, acts as a reference plane for the antenna, and can be used for ESD protection. By combining these functions into a single integrated structure rather than adding separate components, the overall device complexity is minimized while achieving the desired RF performance.
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 improves the radiation efficiency of RF signals, preventing signal absorption in the body and allowing for effective monitoring and transmission of biosignals, thereby enhancing the accuracy and reliability of health monitoring systems.
Implementation Method 1
a ground layer disposed between the main board and the conductive electrode to reflect the RF signal radiated from the antenna to the body
Data Source
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AI summary
A body sensor, a system including the body sensor and a method of transmitting a biosignal are provided. A wearable body sensor includes a conductive electrode configured to conduct a biosignal from a body, a main board comprising a radio frequency (RF) communication circuit to generate an RF signal based on the biosignal, and an antenna disposed on the RF communication circuit to radiate the RF signal.