Complex Measurement Receiver for Proximal User Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mobile devices face challenges in detecting user proximity for Specific Absorption Rate (SAR) exposure, particularly in body-worn positions, due to regulatory limits, and rely on capacitive sensors for both SAR reduction and adaptive antenna impedance matching, which are not always accurate.
Innovation Solution
A communication device employs a complex measurement receiver to detect antenna impedance changes and reduce output power when SAR thresholds are exceeded, eliminating the need for capacitive sensors and enabling accurate Total Radiated Power (TRP) and Total Integrated Sensitivity (TIS) measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive sensors are used to detect body-worn position for SAR reduction, then SAR compliance can be achieved, but measurement precision and reliability are insufficient
Solution Approach 1:
The patent replaces capacitive sensors (electrical field-based detection) with a measurement receiver that directly measures antenna impedance changes (electrical parameter detection). This substitution uses the antenna's own electrical characteristics as the detection mechanism, eliminating the need for separate capacitive sensing elements and providing more direct and accurate detection of body-worn positions.
Solution Approach 2:
The antenna system serves dual functions: it both transmits RF signals and acts as the sensing element for detecting body-worn positions through impedance changes. The measurement receiver monitors the antenna's own electrical characteristics, allowing the antenna to 'sense' its environment without requiring separate sensing components, thereby improving both reliability and precision.
2Device complexity
If a single complex measurement receiver is used for both SAR reduction and adaptive impedance matching, then device complexity is reduced, but functional accuracy must be maintained
Solution Approach 1:
The measurement receiver is designed to perform multiple functions: detecting body-worn positions for SAR reduction and measuring antenna impedance changes for TRP and TIS optimization. By making the receiver universal, the patent eliminates the need for separate capacitive sensors while maintaining the precision required for both SAR compliance and performance optimization through adaptive impedance matching.
Solution Approach 2:
The patent merges the SAR detection function and the TRP/TIS measurement function into a single measurement receiver system. This consolidation combines previously separate sensing and measurement capabilities into one integrated receiver that monitors antenna impedance characteristics for both regulatory compliance and performance optimization purposes.
3Object-affected harmful factors
If transmitter output power is reduced in body-worn position, then SAR regulatory limits are met, but TRP performance deteriorates
Solution Approach 1:
The patent implements dynamic adaptive impedance matching that adjusts the antenna system's electrical characteristics in real-time based on detected body-worn positions. By dynamically optimizing the impedance match, the system maximizes TRP within the constraints of SAR limits, rather than simply reducing power when body-worn position is detected. This dynamic adjustment allows the system to maintain better TRP performance while still meeting SAR requirements.
Data Source
AI summary
A method, communication device, and computer program product mitigates Specific Absorption Rating (SAR) exposure to a user who is proximate to a communication device. The method includes an on-device measurement receiver of the communication device detecting a first signal corresponding to transmit signals that are reflected by a first antenna. The method includes a controller determining, based on the first signal a first set of values for a power efficiency parameter. The method includes the controller determining whether both the first value and the second value differ from respective baseline values by respective Specific Absorption Rate (SAR) threshold amounts. In response to the controller determining that both the first and second values differ by the respective SAR threshold amounts, the controller adjusts the power delivered to the first antenna.