Mobile Antenna Impedance Sensing for Adaptive Transmit Power

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Solution Overview

Problem

Mobile computing devices experience increased power consumption and dropped calls due to antenna impedance mismatch, especially when in talk position, as the user's head absorbs radiating energy, leading to reduced battery life and poor communication quality.

Innovation Solution

The device determines the user environment based on detected antenna impedance or current, confirms that the total radiation power exceeds the minimum threshold, and adjusts the conducted power level and antenna impedance matching to reduce power consumption while maintaining acceptable quality of service.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mobile computing device operates at high power levels to maintain communication quality, then communication reliability is improved, but power consumption increases and battery life is reduced

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by continuously monitoring antenna impedance and dynamically adjusting the conducted power level based on real-time impedance conditions. The system transitions from static power operation to dynamic power adaptation, where power levels are adjusted in response to changing user environments (talk position vs. hands-free), thereby maintaining communication reliability while optimizing power consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters of the antenna system by adjusting the conducted power level based on detected antenna impedance. When impedance indicates talk position (higher loss), the system reduces power level; when impedance indicates hands-free environment (lower loss), the system can operate at higher efficiency. This parameter adaptation resolves the contradiction between reliability and power consumption.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If the mobile computing device operates in talk position, then voice communication functionality is improved, but power consumption increases due to head absorption of radiating energy

Engineering Contradiction:

Improvevoice communication functionalityVSAvoidpower consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent implements feedback by continuously monitoring antenna impedance, which changes based on the user's head proximity during talk position. The impedance measurement provides feedback about the loss conditions, and the system uses this feedback to adjust the conducted power level accordingly. This closed-loop control enables the system to maintain voice communication quality while adapting power consumption to the actual radiation loss conditions.

Inventive Principle:

Principle #23Feedback

3Reliability

If antenna impedance mismatch occurs, then communication quality deteriorates with dropped calls, but increasing power levels to compensate increases power consumption

Engineering Contradiction:

Improvecommunication qualityVSAvoidenergy loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies self-service by enabling the antenna system to automatically detect and adapt to impedance conditions without external intervention. The system monitors its own impedance characteristics and autonomously adjusts the conducted power level to compensate for mismatch conditions. This self-adjusting mechanism maintains communication quality while minimizing unnecessary energy loss that would occur with constant high-power operation.

Inventive Principle:

Principle #25Self-service

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

This approach achieves significant power savings, extending battery life and maintaining communication quality by optimizing power levels and impedance matching based on user environment, with up to 34% power savings in hands-free environments and 21% in talk position.

Implementation Method 1

the head of a user is a lossy dielectric material and typically absorbs 1-6 dB energy radiating from the mobile computing device

Methodology Applied

Scientific EffectElectromagnetic radiation absorption: Absorption (EM radiation)

Implementation Method 2

A mobile computing device may be arranged to determine a user environment based on detected antenna impedance

Methodology Applied

Scientific EffectElectrical impedance detection: Electrical Resistance

Data Source

PatentUS8577426B2Systems and techniques for reducing power consumption in a mobile computing device

Publication Date: 2013.11.05 QUALCOMM INC

AI summary

Various embodiments are directed to systems and techniques for reducing power consumption in a mobile computing device. In one or more embodiments, a mobile computing device may be arranged to determine a user environment based on detected antenna impedance or detected current. After the user environment is determined, the mobile computing device may confirm that total radiation power (TRP) for the mobile computing device at an initial conducted power level exceeds the minimum TRP threshold required by the network carrier to receive acceptable quality of service (QoS). Based on the excess TRP for the particular user environment, the mobile computing device may determine a reduced conducted power level to be input to an antenna system. Accordingly, significant power savings may be achieved. To save additional power, the mobile computing device may automatically adjust and/or improve antenna impedance matching based on user environment allowing a further reduction in conducted power.