Mobile Terminal Antenna Power Control for SAR Reduction
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Solution Overview
Problem
Existing mobile communication terminals face a challenge in reducing Specific Absorption Rate (SAR) values without compromising transmission performance, as methods like using a grip sensor to weaken electromagnetic waves can degrade communication strength.
Innovation Solution
A mobile communication terminal employing multiple antennas, where power is applied in a coordinated manner, with each antenna transmitting data using a power level below a threshold but summing to a value above another threshold, ensuring reduced SAR without degrading transmission signal strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If power is reduced to decrease SAR value, then electromagnetic wave absorption by human body is reduced, but transmission signal strength is degraded
Solution Approach 1:
The patent divides the transmission function into multiple antennas (first antenna and second antenna). Each antenna transmits at reduced power levels individually (both below a first threshold), but collectively they provide sufficient transmission strength (sum above a second threshold). This segmentation allows SAR reduction while maintaining communication reliability.
2Object-affected harmful factors
If grip sensor is used to reduce electromagnetic wave strength, then SAR value is decreased, but communication performance is degraded
Solution Approach 1:
Instead of using a grip sensor to uniformly reduce power, the patent segments the transmission across multiple antennas with coordinated power control. Each antenna operates below individual power thresholds, and the sum of powers maintains communication performance, eliminating the need for grip sensor detection.
Solution Approach 2:
The system automatically manages power distribution across antennas without requiring external sensing or user interaction. The base station coordinates with the mobile terminal to allocate power levels that satisfy both SAR constraints and communication requirements, making the system self-regulating.
3Reliability
If single antenna transmits at high power, then transmission signal strength is maintained, but SAR value increases
Solution Approach 1:
The patent segments the high-power transmission function across multiple antennas. Instead of one antenna transmitting at high power (which would increase SAR), multiple antennas transmit at lower individual power levels, with the sum of powers maintaining the required transmission strength while keeping each antenna's SAR contribution below thresholds.
Data Source
AI summary
A method of controlling a mobile communication terminal including a first antenna and a second antenna is provided. The method includes receiving transmission data to be transmitted, applying first power smaller than a first threshold value to the first antenna, applying second power smaller than the first threshold value to the second antenna, and cooperatively transmitting the transmission data based on the first power and the second power, respectively, by the first antenna and the second antenna, wherein a sum of the first power and the second power is larger than a second threshold value.