Multilayer 5G Vehicle Antenna Layout to Reduce Signal Reflections

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Solution Overview

Problem

Existing millimeter-wave antennas for 5G applications face issues with unwanted signal reflections due to conductive elements acting as ground planes, which affect transmission quality, and increasing the distance between radiating elements and ground planes leads to increased cost and dimensions, making them unsuitable for vehicles with limited space.

Innovation Solution

A multilayer antenna structure with strategically placed slots, conductive lines, and through openings to minimize signal reflections, while maintaining compact size and low cost, using dielectric materials like ROGERS RO4350B and RO4450 for layers and conductive materials like copper.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the distance between radiating elements and ground planes is increased to reduce signal reflections, then transmission quality is improved, but antenna dimensions and cost increase

Engineering Contradiction:
Improvetransmission qualityVSAvoidantenna dimensions
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent removes the traditional ground plane structure from the antenna design. Instead of using a continuous conductive ground plane that causes reflections, the invention extracts this element and replaces it with a slot-based feeding structure where signal transmission occurs through dielectric layers without reflective ground planes, thereby eliminating the need for large separation distances.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces dielectric layers as intermediary structures between radiating elements and what would traditionally be ground planes. These dielectric layers serve as mediators that guide and isolate signals without creating the mirror effects that conductive ground planes produce, enabling compact antenna design while maintaining transmission quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the distance between radiating elements and ground planes is increased to reduce signal reflections, then transmission quality is improved, but manufacturing cost increases

Engineering Contradiction:
Improvetransmission qualityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the traditional ground plane structure from the antenna design. Instead of using a continuous conductive ground plane that causes reflections, the invention extracts this element and replaces it with a slot-based feeding structure where signal transmission occurs through dielectric layers without reflective ground planes, thereby eliminating the need for large separation distances.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The dielectric layers in the patent serve multiple functions simultaneously: they act as signal transmission media, provide electrical isolation between elements, replace the traditional ground plane function, and enable compact integration. This multi-functionality reduces the need for additional components and complex assembly, thereby controlling manufacturing costs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If multiple antennas are deployed in vehicles to overcome metal shielding, then communication reliability is improved, but space requirements and complexity increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidantenna system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent converts the traditionally harmful effect of metal shielding into a beneficial feature by designing antennas that can operate effectively in the presence of metal surfaces. The slot-based structure and dielectric isolation allow the antenna to penetrate or work around metal shielding without requiring excessive separation, turning the vehicle's metal body from an obstacle into a manageable environment.

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

Solution Approach 2:

The patent segments the antenna structure into distinct functional layers (radiating elements, dielectric layers, slots) that can be independently optimized and manufactured. This segmentation allows for modular deployment strategies where multiple antennas can be integrated into vehicle structures with minimal interference, reducing overall system complexity.

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

The solution effectively reduces unwanted signal reflections, optimizes signal matching, and maintains a compact design suitable for vehicles, enhancing transmission quality without significant cost or size penalties.

Implementation Method 1

the presence in the structure of the antenna of conductive elements that act as ground planes could create within the antenna mirror effects with reflected signals that overlap, in a phase-shifted manner, with the signals to be transmitted

Methodology Applied
Scientific EffectDielectric isolation: Dielectric

Data Source

PatentEP4047751B1Millimeter-wave antenna for 5g applications and vehicle comprising such antenna
Publication Date: 2026.03.18 ASK IND SPA
  • EP4047751B1 patent drawingFigure 1
  • EP4047751B1 patent drawingFigure 2
  • EP4047751B1 patent drawingFigure 3

AI summary

Millimeter-wave antenna (1) for 5G applications, comprising a multilayer structure which includes at least: - an upper outer layer (10) comprising at least a plurality of first radiating elements (14) arranged spaced apart from each other on a first dielectric sublayer (12); - a first inner layer (20) arranged below the upper outer layer (10) and comprising a plurality of through slots (24) suitable for conveying, towards the plurality of first radiating elements (14), the feeding signals to be radiated; - a second inner layer (30) arranged below and adjacent to the first inner layer (20), the second inner layer (30) comprising at least one dielectric sublayer (32) on which a plurality of conductive lines (34) suitable for conducting the feeding signals to be radiated towards the plurality of first radiating elements (14); - a further layer (40) arranged below and adjacent to the second inner layer (30) and comprising a plurality of first through openings (44), each of the first through openings (44) being formed on the further layer (40) in a position corresponding to the position of at least one associated through slot (24) of the plurality of through slots (24).