Wireless Terminal SAR Reduction via Coupling Signal
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Solution Overview
Problem
Current wireless terminals face challenges in reducing Specific Absorption Rate (SAR) peak values while maintaining communication quality and miniaturization, as existing methods to counteract human body proximity often increase electromagnetic energy absorption.
Innovation Solution
A wireless terminal design incorporating a first antenna for communication signals and a second antenna to feed a coupling signal, processed by a signal processing module to adjust amplitude and phase, reducing SAR peak values by minimizing near-field superposed signal energy and redirecting radiation away from the human body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a matching network is used to counteract antenna mismatch due to human body proximity, then mismatch loss on radio-frequency circuit is reduced, but electromagnetic energy entering the human body increases and SAR peak value increases
Solution Approach 1:
The patent introduces a second antenna as an intermediary element that generates a coupling signal to interact with the human body's electromagnetic field. This coupling signal acts as a mediator that modifies the overall electromagnetic field distribution, reducing the harmful SAR effect on the human body while maintaining communication quality through the first antenna's feed signal.
Solution Approach 2:
The patent changes the electromagnetic field parameters by introducing a coupling signal with specific amplitude and phase characteristics. By adjusting these parameters, the system modifies the near-field distribution to reduce energy concentration on the human body surface, thereby lowering SAR peak values while preserving communication performance.
2Volume of moving object
If the wireless terminal is miniaturized to improve portability, then device size is reduced, but radiation characteristic control and SAR management become more difficult
Solution Approach 1:
The patent combines the functions of two antennas into a unified system where the first antenna handles primary communication and the second antenna manages SAR reduction through coupling signals. This merged approach allows miniaturization while maintaining sophisticated electromagnetic field control capabilities that would be difficult to achieve with a single antenna.
Solution Approach 2:
The second antenna serves multiple functions: it generates coupling signals for SAR reduction, interacts with the human body's electromagnetic field, and works cooperatively with the first antenna to maintain communication quality. This multi-functionality reduces the need for additional separate components, supporting terminal miniaturization.
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
Effectively reduces SAR peak values by altering the antenna's radiation distribution to concentrate energy in non-human-body directions, improving communication quality and reducing electromagnetic absorption by the human body.
Implementation Method 1
a second antenna configured to feed a coupling signal when the first antenna receives or transmits the communication signal
Implementation Method 2
adjust an amplitude and a phase of the coupling signal, so as to change an amplitude ratio and a phase difference between the coupling signal and the communication signal and to reduce energy of a near-field superposed signal
Data Source
AI summary
A wireless terminal with a reduced Specific Absorption Rate (SAR) peak value and a method for reducing an SAR peak value by using the wireless terminal are disclosed. The wireless terminal with a reduced SAR peak value includes a first antenna configured to receive or transmit a communication signal, and further includes: a second antenna configured to feed a coupling signal when the first antenna receives or transmits the communication signal, and a signal processing module configured to process the coupling signal to reduce an SAR peak value of the communication signal for a human body. The energy of a superposed signal in a human body orientation is reduced by superposing the coupling signal with the communication signal, so as to reduce the SAR peak value effectively.