Passive UHF RFID Antenna Grid for EMI-Resistant Long-Range Reading

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Solution Overview

Problem

Conventional RFID antennas face limitations in communication range and are prone to interference, particularly in UHF systems, necessitating improved designs for enhanced performance and reduced interference.

Innovation Solution

A passive RFID antenna with a grid pattern design featuring multiple layers of metal discs, reflectors, and a base shield, utilizing materials like copper and brass, to enhance signal directionality and block unwanted signals, allowing for extended reading distances of Passive UHF RFID tags.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional RFID antenna is used, then the device is simple and easy to manufacture, but the antenna is susceptible to EMI and RFI that degrades performance

Engineering Contradiction:
Improveantenna performance stabilityVSAvoidantenna structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a nested structure where an inner antenna element is positioned within a larger antenna structure. The inner element serves as a parasitic element that is electrically coupled to the main driven element, creating a nested configuration that provides EMI and RFI immunity while maintaining a relatively compact and manufacturable design.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent introduces an intermediary parasitic element that couples between the driven element and the surrounding environment. This intermediate element acts as a shield or buffer that protects the main antenna from electromagnetic interference while allowing the antenna to maintain its functional simplicity and ease of manufacture.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the antenna is made more complex to improve EMI/RFI immunity, then reliability improves, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveimmunity to EMI and RFIVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The nested configuration allows the parasitic element to be integrated within the existing antenna structure, utilizing shared support elements and common mounting mechanisms. This nesting approach achieves improved EMI/RFI immunity without requiring completely separate manufacturing processes, thereby maintaining ease of manufacture.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The parasitic element serves multiple functions: it provides EMI and RFI immunity, acts as a reflector or director for signal enhancement, and can be integrated with existing structural components. This multi-functionality reduces the need for additional dedicated components, simplifying manufacturing while achieving reliability improvements.

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

3Object-affected harmful factors

If a parasitic element is added to the antenna, then EMI and RFI immunity is improved, but the device complexity increases

Engineering Contradiction:
Improvesusceptibility to EMI and RFIVSAvoidnumber of antenna elements
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The parasitic element is nested within the existing antenna structure rather than being added as a completely separate component. This nesting allows shared support structures, common feeding mechanisms, and integrated mounting, thereby reducing the overall device complexity despite adding functional elements for EMI/RFI immunity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent merges the parasitic element with the main antenna structure, combining multiple functions into a unified design. The parasitic element is electrically coupled to the driven element and shares physical support structures, effectively merging what could be separate components into a single integrated antenna system that reduces overall complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 new antenna design enables reading Passive UHF RFID tags at distances beyond conventional standards, achieving consistent communication up to 30 meters with improved signal control and reduced interference.

Implementation Method 1

the parasitic antenna element, when excited by the driven element, radiates an electromagnetic signal that is 180 degrees out of phase

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

mitigate one or more of the following antenna performance degrading conditions: antenna performance degradation due to electromagnetic interference (EMI), radio frequency interference (RFI), and multipath signal interference

Methodology Applied
Scientific EffectMultipath interference mitigation: Reflection

Data Source

PatentEP4494213B1Improved RFID antenna
Publication Date: 2026.05.06 ATTACHE HLDG LLC
  • EP4494213B1 patent drawingFigure 1
  • EP4494213B1 patent drawingFigure 2
  • EP4494213B1 patent drawingFigure 3

AI summary

The present invention provides an improved RFID Antenna. The improved RFID antenna comprises an antenna grid panel; a plurality of antennas having a square shape structure with a ceramic material attached in front of the square shape structure; a plurality of reflectors positioned behind each of the antennas; a base positioned behind the plurality of reflectors, the base is attached to the antenna grid panel; a plurality of antenna shafts; and the plurality of reflectors connected to the each of the antennas by an antenna shaft which extends from the base through the center of each reflector.