Vehicle Antenna Array Spacing for Stable Reception Under Reflected Waves

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle-to-vehicle communication systems face challenges in maintaining stable communication due to periodic fluctuations in signal reception levels caused by interference from multiple reflected waves in line-of-sight environments, leading to null points or low reception levels.

Innovation Solution

An antenna array configuration for vehicle-to-vehicle communication that includes multiple antennas shifted by odd multiples of the half-period of the maximum and minimum fluctuation periods of received radio waves, optimizing the spacing to prevent null points and enhance reception quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple antennas are arranged for spatial diversity, then communication reliability is improved, but reception level fluctuation and null points occur due to reflected wave interference

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidreception level fluctuation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the spatial arrangement parameters of antennas by positioning them at odd multiple half-period intervals of the fluctuation period. This parameter optimization transforms the antenna spacing from conventional fixed distances to dynamically calculated positions based on the fluctuation characteristics of reflected waves, thereby resolving the contradiction between maintaining spatial diversity and avoiding null points.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary identification of the fluctuation period of received signals before arranging the antennas. By pre-determining the characteristics of reflected wave interference and calculating the appropriate antenna spacing in advance, the system proactively prevents null points from occurring rather than reacting to them afterward.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If antenna spacing is increased to avoid null points, then reception stability is improved, but antenna array size and device complexity increase

Engineering Contradiction:
Improvereception stabilityVSAvoidantenna array configuration
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent optimizes antenna spacing parameters to odd multiple half-period intervals, which provides the necessary separation to avoid null points while minimizing the overall antenna array size. This parameter optimization achieves reception stability without excessive increases in device complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent divides the antenna array into multiple antennas positioned at specific intervals rather than using a single large spacing. This segmentation allows the system to achieve stability through distributed positioning at manageable distances, reducing overall device complexity while maintaining reception stability.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If conventional antenna spacing is used, then device complexity is reduced, but communication fails due to null points in reflected wave environments

Engineering Contradiction:
Improveantenna arrangementVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent modifies the antenna spacing parameter from conventional fixed values to odd multiple half-period intervals based on signal fluctuation characteristics. This parameter change maintains relatively simple device complexity while dramatically improving communication reliability by preventing null points in reflected wave environments.

Inventive Principle:
Principle #35Parameter changes

4Object-affected harmful factors

If antennas are positioned to avoid reflected wave interference, then reception quality is improved, but the system becomes less adaptable to different environments

Engineering Contradiction:
Improvereception qualityVSAvoidenvironmental adaptability
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent employs a dynamic approach by identifying the fluctuation period specific to each environment and adjusting antenna positions accordingly. Rather than using a fixed arrangement, the system adapts its configuration based on the actual reflected wave characteristics of the operating environment, thereby maintaining high reception quality across diverse settings.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the antenna positioning parameters based on environment-specific fluctuation period measurements. By recalibrating the odd multiple half-period intervals according to actual environmental conditions, the system maintains optimal reception quality while adapting to different operational contexts.

Inventive Principle:
Principle #35Parameter changes

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

The proposed antenna array configuration effectively stabilizes reception by preventing null points and improving signal quality, ensuring consistent communication performance in diverse environments.

Implementation Method 1

periodic fluctuations in signal reception levels caused by interference from multiple reflected waves

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 2

interference from multiple reflected waves in line-of-sight environments

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4395074B1Antenna device, system, communication device, and program
Publication Date: 2025.12.17 SOFTBANK CORPORATION
  • EP4395074B1 patent drawingFigure 1
  • EP4395074B1 patent drawingFigure 2
  • EP4395074B1 patent drawingFigure 3

AI summary

Provided is an antenna apparatus mounted on a movable object, the antenna apparatus including an antenna array including: a plurality of first antennas which are arranged by being shifted by a distance equivalent to an odd multiple of a half period of a maximum fluctuation period of a radio wave having a longest fluctuation period among a plurality of radio waves received from an antenna of a communication partner; and a plurality of second antennas which are respectively arranged by being shifted with respect to the plurality of first antennas by a distance equivalent to an odd multiple of a half period of a minimum fluctuation period of a radio wave having a shortest fluctuation period among the plurality of radio waves.