Diversity Antenna System for Isotropic Radiation in Gas Meters

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Solution Overview

Problem

Conventional antenna configurations in gas meters face limitations such as restricted size, asymmetric radiation directivity, and severe multipath fading, which hinder effective wireless communication, especially in mesh network environments.

Innovation Solution

The wireless communication device employs a diversity antenna system with inverted L-shaped antenna elements and a circuit board configuration that includes an impedance adjustor and ground pattern to achieve isotropic radiation directivity and improved performance, optimizing antenna placement and radiation efficiency within the constraints of a gas meter's metal housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a conventional antenna configuration is used inside a gas meter, then the antenna size is restricted due to the limited space within the meter housing, but the radiation directivity becomes asymmetric which hinders effective wireless communication in all directions

Engineering Contradiction:
Improveantenna sizeVSAvoidradiation directivity pattern
Core Design Contradiction:
Volume of moving objectVSShape

Solution Approach 1:

The patent applies asymmetry by intentionally designing the antenna structure with specific asymmetric elements (such as the inverted L-shape configuration and strategic placement of ground patterns) to compensate for the asymmetric radiation pattern caused by the metal housing. This asymmetric design allows the antenna to achieve more uniform omnidirectional radiation despite the constrained and asymmetric installation environment within the gas meter.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by creating different ground patterns at different locations around the antenna structure. Specific ground patterns are strategically placed in different radial directions to locally adjust and enhance radiation in those specific directions, thereby achieving overall omnidirectional radiation coverage despite the limited space and asymmetric constraints within the meter housing.

Inventive Principle:
Principle #3Local quality

2Device complexity

If the antenna is placed inside the metal housing of the gas meter, then the structure is compact and protected, but severe multipath fading occurs which degrades wireless communication quality

Engineering Contradiction:
Improvehousing structure integrationVSAvoidwireless communication stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces ground patterns as intermediary elements between the antenna and the metal housing. These ground patterns act as mediators that manipulate the electromagnetic field distribution, reducing the harmful multipath effects caused by reflections from the metal housing walls while maintaining the compact integrated structure. The ground patterns effectively decouple the antenna from the adverse effects of the enclosing metal structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful multipath reflections from the metal housing into beneficial effects by strategically designing ground patterns that utilize these reflections constructively. The ground patterns are positioned and dimensioned to transform the potentially harmful reflected waves into constructive interference patterns that enhance the overall signal strength and reduce fading, thereby turning the metal housing from a source of interference into a component that can support reliable communication.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If a single antenna is used to reduce device complexity, then the structure is simpler, but diversity gain is insufficient which limits communication reliability in mesh network environments

Engineering Contradiction:
Improveantenna system structureVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent merges multiple antenna elements and ground patterns into a single integrated antenna system. Rather than using separate diversity antennas that would increase complexity, the invention combines multiple radiating elements and ground patterns into one unified structure that provides both the simplicity of a single antenna system and the diversity gain of multiple elements through their coordinated operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the single antenna structure into multiple functional elements (inverted L-shaped elements, multiple ground patterns at different locations) that operate together to provide diversity gain. This segmentation allows each element to contribute to different aspects of the radiation pattern, achieving spatial diversity and improved reliability while maintaining the simplicity of a single integrated antenna system.

Inventive Principle:
Principle #1Segmentation

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 configuration enhances wireless communication stability and range by ensuring isotropic radiation in all directions, reducing multipath fading, and increasing diversity gain, thereby supporting reliable mesh network communication without the need for external host machines.

Implementation Method 1

employing a diversity antenna system including a plurality of inverted L-shaped antenna elements... radiate magnetic fields in different directions and radite electric fields in difference directions

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

a circuit board configuration that includes an impedance adjustor and ground pattern to achieve isotropic radiation directivity and improved performance

Methodology Applied
Scientific EffectElectromagnetic field control: Electromagnetic Induction

Data Source

PatentEP3509160B1Wireless communication device
Publication Date: 2021.09.29 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3509160B1 patent drawingFigure 1
  • EP3509160B1 patent drawingFigure 2A~2C
  • EP3509160B1 patent drawingFigure 3

AI summary

A wireless communication device includes: flow-rate measuring unit (3) connected to fluid pipe (2); and first antenna element (4) that transmits and receives a radio wave. First antenna element (4) has a longer side orthogonal to an axis of fluid pipe (2). According to this configuration, a direction of a plane of polarization of a radio wave radiated from first antenna element (4) is orthogonal to fluid pipe (2). Thus, the radio wave is not reflected by fluid pipe (2) but propagates in a direction toward fluid pipe (2), namely, in a rear surface direction of a meter including the wireless communication device.