Antenna Array Power Backoff for MPE and SAR Compliance
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Solution Overview
Problem
Existing wireless communication technologies face challenges in maintaining radiation performance of antenna arrays while adhering to maximum permissible exposure and specific absorption rate regulations, often leading to unnecessary power backoff that reduces effective isotropic radiated power.
Innovation Solution
The solution involves adjusting power backoff values based on the feed polarity and number of elements in the antenna array, allowing for singular or plural configurations to optimize radiation performance without exceeding regulatory limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If uniform power backoff is applied to the antenna array, then electromagnetic exposure criteria (MPE and SAR) are met, but radiation performance and effective isotropic radiated power are deteriorated
Solution Approach 1:
The patent applies local quality by differentiating power backoff treatment across individual antenna elements rather than applying uniform backoff. The controller determines which specific elements are adjacent to the human body and applies power backoff only to those elements, while maintaining full power for non-adjacent elements. This localized approach preserves overall radiation performance while still meeting electromagnetic exposure criteria.
Solution Approach 2:
The patent segments the antenna array into individual elements and evaluates each element's proximity to the human body separately. By dividing the array into discrete controllable units and applying power backoff selectively to adjacent elements only, the system avoids the performance degradation caused by uniform backoff across all elements while still protecting against excessive electromagnetic exposure.
2Object-affected harmful factors
If power backoff is performed using a uniformly-set backoff value, then electromagnetic exposure criteria are satisfied, but the effective isotropic radiated power is reduced unnecessarily
Solution Approach 1:
The patent implements local quality by applying power backoff selectively to only those antenna elements adjacent to the human body, rather than uniformly across all elements. This localized differentiation allows the system to meet SAR criteria for exposed elements while maintaining full transmission power for non-exposed elements, thereby preserving communication efficiency and avoiding unnecessary productivity loss.
Solution Approach 2:
The patent applies dynamics by making the power backoff configuration adaptive rather than static. The controller dynamically determines which antenna elements are adjacent to the human body and adjusts power backoff accordingly. This dynamic adaptation allows the system to optimize the balance between meeting SAR criteria and maintaining communication efficiency based on real-time conditions.
Data Source
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AI summary
An electronic device is provided. The electronic device includes an antenna array including a plurality of elements arranged to perform beamforming, wherein a first number corresponds to a total number of the plurality of elements, a processor operatively connected to the antenna array, and a memory, wherein the memory stores instructions that, when executed, cause the processor to identify a second number of the plurality of elements that are performing the beamforming, determine a first backoff value stored based on the second number, and perform a power backoff operation according to the first backoff value.