EBG-Surrounded Antenna Array for Low Front-to-Back Radiation

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Solution Overview

Problem

Existing 5G antenna arrays face issues with low isolation between elements and high front-to-back ratios, leading to shorter communication distances and poor spatial efficiency.

Innovation Solution

A communication device incorporating an antenna array surrounded by an Electromagnetic Band Gap (EBG) structure, with specific symmetrical patterns and dimensions to suppress the front-to-back ratio, enhancing communication distance and spatial efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If antenna elements are placed closer together to improve spatial efficiency, then spatial efficiency is improved, but isolation between antenna elements deteriorates

Engineering Contradiction:
Improvespatial efficiencyVSAvoidisolation between antenna elements
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces EBG (Electromagnetic Band Gap) structures as intermediary elements between antenna elements. These EBG units act as electromagnetic barriers that block surface wave propagation while allowing the antenna elements to be positioned closer together, thus maintaining isolation between elements while improving spatial efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the electromagnetic parameters of the space between antenna elements by introducing EBG structures with specific unit cell dimensions (0.05λ×0.05λ) and spacing (0.02λ). This changes the effective electromagnetic environment, creating bandgap frequencies that prevent surface wave propagation and improve element isolation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If antenna elements are placed closer together to improve spatial efficiency, then spatial efficiency is improved, but communication distance deteriorates

Engineering Contradiction:
Improvespatial efficiencyVSAvoidcommunication distance
Core Design Contradiction:
ProductivityVSLength of moving object

Solution Approach 1:

The EBG structures serve as intermediary elements that enable closer antenna placement while preventing the degradation of radiation performance. By blocking surface waves that would otherwise cause interference and energy loss, the EBG structures maintain communication distance even as spatial efficiency improves through closer element spacing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potentially harmful surface wave propagation into a beneficial effect by using EBG structures to create electromagnetic bandgaps. The surface waves that would normally cause interference are blocked by the EBG structures, transforming what would be a harmful phenomenon into an opportunity to improve both spatial efficiency and communication distance simultaneously.

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

3Device complexity

If conventional antenna arrays are used, then device complexity is low, but front-to-back ratio is too high

Engineering Contradiction:
Improveantenna array structureVSAvoidfront-to-back ratio
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the antenna array by surrounding each antenna element or group of elements with individual EBG structures. This segmentation creates isolated electromagnetic environments for each element, controlling the radiation pattern and reducing the front-to-back ratio without requiring complex overall array configurations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the electromagnetic parameters of the antenna system by introducing EBG structures with specific geometric parameters (unit cell size of 0.05λ×0.05λ, spacing of 0.02λ). These parameter changes create electromagnetic bandgaps that control surface wave propagation and modify the radiation pattern, thereby reducing the front-to-back ratio while maintaining relatively simple device structure.

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 EBG structure effectively reduces the front-to-back ratio by 6-8dB, improving communication distance and spatial efficiency of the antenna array.

Implementation Method 1

The EBG structure includes a plurality of EBG units. The EBG units are coupled to the ground plane. The antenna array is surrounded by the EBG structure and enclosed by the EBG structure; wherein the antenna elements are arranged to form a first symmetrical pattern; and wherein the EBG units are arranged to form a second symmetrical pattern.

Methodology Applied
Scientific EffectElectromagnetic Band Gap (EBG):

Data Source

PatentEP3771037B1Communication device
Publication Date: 2026.03.25 DELTA ELECTRONICS INC(CN)
  • EP3771037B1 patent drawingFigure 1
  • EP3771037B1 patent drawingFigure 2
  • EP3771037B1 patent drawingFigure 3

AI summary

A communication device includes a ground plane, an antenna array, and an EBG (Electromagnetic Band Gap) structure. The antenna array includes a plurality of antenna elements. The EBG structure includes a plurality of EBG units. The EBG units are coupled to the ground plane. The antenna array is surrounded by the EBG structure. The EBG structure is configured to suppress the front-to-back ratio of the radiation efficiency of the antenna array.