Inverted-F Antenna RFID Substrate for Metallic Surfaces

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Solution Overview

Problem

Conventional RFID tags face communication challenges when mounted on metallic articles, with poor communication distance and reliability due to the radiating plate not functioning effectively and potential semiconductor element damage.

Innovation Solution

An RFID tag board with a circuit board featuring a recess for the semiconductor element and a radiation member, forming an inverted-F antenna configuration that allows direct attachment to metallic articles, enhancing communication characteristics and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the radiating plate is disposed in the vicinity of the circuit board, then the antenna function is enhanced, but the semiconductor element is at risk of damage due to potential contact with metallic articles

Engineering Contradiction:
Improveantenna functionVSAvoidsemiconductor element damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the antenna function from the semiconductor element mounting area by using the inverted-F antenna structure. The radiating element is positioned and oriented such that it performs antenna functions while being spatially separated from the semiconductor element, preventing contact damage while maintaining enhanced antenna performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inverted-F antenna structure is integrated into the circuit board assembly with the semiconductor element nested within the board structure. The antenna's radiating element extends from the board in a configuration that provides antenna functionality while the semiconductor element remains protected within the board's recess, preventing direct exposure to harmful factors from metallic articles.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If a conventional RFID tag structure is used, then the manufacturing is simple, but the resonance frequency shifts when attached to metallic articles

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidresonance frequency stability
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The inverted-F antenna structure serves multiple functions: it provides the radiating element for RFID communication, acts as a mounting structure for the semiconductor element, and functions as a stable resonance element when attached to metallic articles. This multi-functionality maintains manufacturing simplicity while ensuring resonance frequency stability across different mounting conditions.

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

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 enables RFID tags with improved communication distance and reliability when attached to metallic articles, maintaining semiconductor element safety and reducing resonance frequency shifts.

Implementation Method 1

a radiation member 20; to transmit and receive radio waves to and from the radiation member

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

the capacitor defining, with the antenna and the microcircuit, a given resonance frequency substantially equal to the frequency of an external reader

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 3

forming a capacitor connected in parallel on the antenna... suitable for concentrating the field lines toward the inside of the turn

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3734514B1Substrate for RFID tags, RFID tag and RFID system
Publication Date: 2023.06.14 KYOCERA CORP
  • EP3734514B1 patent drawingFigure 1
  • EP3734514B1 patent drawingFigure 2
  • EP3734514B1 patent drawingFigure 3

AI summary

A substrate 30 for RFID tags according to the present invention is provided with: a wiring substrate 10; and a radiation member 20 which is affixed to a first surface 11 of the wiring substrate 10. The wiring substrate 10 is provided with: a dielectric substrate 1 which has the first surface 11, a second surface 12 that is on the reverse side of the first surface and serves as a mounting surface for an article 300, and a recess 1a; a radiation conductor 2 which is arranged on the first surface 11; a ground conductor 3 which is arranged on the second surface 12; a connection conductor 4 which is electrically connected to the radiation conductor 2 and the ground conductor 3; and a first electrode 7a and a second electrode 7b, which are arranged in the recess 1a.