Local Average Absorbed Power Calculation for Multi-Antenna Radio Devices

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Solution Overview

Problem

Conventional methods for measuring local average absorbed power of radio devices with multiple antennas operating in the same frequency band are inefficient, requiring extensive time and potentially missing optimal combinations of transmission powers and phases.

Innovation Solution

A method involving the measurement of electric and/or magnetic fields from multiple antennas, applying weights to combine amplitudes and phases, and calculating three-dimensional absorbed power distributions to select the highest local average absorbed power candidate, reducing the need for repetitive measurements and calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional methods are used to measure local average absorbed power of radio devices with multiple antennas, then measurement completeness may be improved by checking all combinations, but measurement time and labor increase significantly

Engineering Contradiction:
Improvemeasurement completenessVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by first performing a coarse measurement to identify candidate regions with high absorbed power before conducting detailed measurements. This preliminary screening step reduces the search space for subsequent detailed measurements, avoiding the need to measure all possible antenna combinations while ensuring the optimal combination is not missed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the measurement process into two distinct stages: a first measurement for identifying candidate regions and a second measurement for obtaining precise local average absorbed power values. This segmentation allows the system to balance measurement completeness with time efficiency by focusing detailed measurements only on promising candidate regions rather than uniformly measuring all areas.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If measurement points are set at smaller intervals to improve measurement accuracy, then measurement precision improves, but the number of measurements and processing time increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidmeasurement efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies local quality by setting measurement points at smaller intervals only in candidate regions where high absorbed power is expected, while using larger intervals in other areas. This localized refinement of measurement density maintains high measurement accuracy where it matters most while reducing the overall number of measurements and processing time.

Inventive Principle:
Principle #3Local quality

3Reliability

If all combinations of transmission powers and phases are measured to ensure optimal configuration is found, then reliability of result improves, but device complexity and measurement burden increase

Engineering Contradiction:
Improveresult reliabilityVSAvoidmeasurement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses preliminary measurement results to identify candidate regions and guide subsequent detailed measurements. This preliminary action provides a roadmap for where to focus resources, ensuring reliable results are obtained for the most critical configurations without requiring exhaustive measurement of all possible combinations, thus reducing measurement complexity while maintaining result reliability.

Inventive Principle:
Principle #10Preliminary action

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

Significantly reduces labor and time required to determine local average absorbed power by obtaining multiple candidates through varying combinations and calculations, minimizing the likelihood of missing optimal antenna configurations.

Implementation Method 1

an electric and/or magnetic probe measures the electric field strength or magnetic field strength of radio waves

Methodology Applied
Scientific EffectElectromagnetic field measurement: Electromagnetic Induction

Implementation Method 2

a phantom, which simulates the dielectric properties of the human body

Methodology Applied
Scientific EffectDielectric absorption: Dielectric

Data Source

PatentEP2405259B1Absorbed power measuring method, local average absorbed power measuring method, local average absorbed power calculating device, and local average absorbed power calculating program
Publication Date: 2019.03.13 NTT DOCOMO INC
  • EP2405259B1 patent drawingFigure 1~2
  • EP2405259B1 patent drawingFigure 3~4
  • EP2405259B1 patent drawingFigure 5

AI summary

An object of the present invention is to provide a simple way of measuring the local average absorbed power of a radio device having a plurality of antennas. A local average absorbed power measuring method of the present invention has an individual measurement step and a calculation step. In the individual measurement step, the amplitude and phase of the electric field or magnetic field of each one of the plurality of antennas are measured. In the calculation step, local average absorbed power candidates are obtained while weights are being varied. More specifically, in a combination sub-step, given weights are applied to the amplitudes and phases of the electric fields or magnetic fields of the individual antennas, obtained in the individual measurement step, and the results are combined. In a local average absorbed power candidate calculation sub-step, the absorbed power distribution in three-dimensional space is calculated from the combined electric field or combined magnetic field obtained in the combination sub-step, and a local average absorbed power candidate is obtained. In a local average absorbed power selection step, the highest one of the local average absorbed power candidates is specified as the local average absorbed power of the radio device.