RFID Sensing Unit With Separated Chip And Antenna Surfaces

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Solution Overview

Problem

In passive RFID chips with sensing capabilities, the antenna connection and sensing elements are often positioned on the same active surface, leading to interference and reduced sensing performance due to conductive materials blocking light or electrical conductivity affecting RF communication.

Innovation Solution

The RFID chip and inductive coupling loop are configured as a separate sensing unit with the chip on one surface and the antenna on the opposite surface, spaced by a substrate, allowing inductive coupling and minimizing interference, with conductive vias connecting the chip to the antenna.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the antenna connection and sensing elements are positioned on the same active surface, then the device structure is simplified, but interference occurs and sensing performance is reduced due to conductive materials blocking light or electrical conductivity affecting RF communication

Engineering Contradiction:
Improvedevice structureVSAvoidsensing performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The device is divided into two separate surfaces: the first surface contains the antenna connection while the second surface contains the sensing elements. This spatial segmentation eliminates the interference between conductive materials and sensing elements that would occur if they were positioned on the same surface, thereby improving sensing performance without significantly increasing overall device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional layout where all components are on the same surface to a three-dimensional configuration utilizing both surfaces of the substrate. By placing the antenna on one surface and sensing elements on the opposite surface, the invention resolves the interference issue while maintaining a compact form factor.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the RFID chip is placed closer to the monitored surface, then sensing capability is improved, but RF communication performance is compromised due to interference from conductive materials

Engineering Contradiction:
Improvesensing capabilityVSAvoidRF communication performance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

By separating the antenna and sensing elements onto opposite surfaces of the substrate, the invention allows the sensing elements to be positioned close to the monitored surface for improved sensing capability, while the antenna remains on the opposite surface away from interfering conductive materials, thus maintaining RF communication performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The substrate acts as an intermediary structure that enables the sensing elements to be positioned close to the monitored surface while simultaneously isolating the antenna from interfering conductive materials. The substrate's thickness and material properties mediate between the conflicting requirements of close proximity for sensing and distance from interference for RF communication.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enhances dynamic response by separating the antenna from the sensing circuitry, improving RF communication and sensing capabilities while allowing closer proximity to the monitored surface without compromising RF performance.

Implementation Method 1

the first surface of the substrate is arranged adjacent to the RFID booster antenna to inductively couple the coupling antenna to the RFID booster antenna

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4488877A1RFID sensing unit and RFID sensor device including the same
Publication Date: 2025.01.08 ASSA ABLOY AB
  • EP4488877A1 patent drawingFigure 1~2
  • EP4488877A1 patent drawingFigure 3~4
  • EP4488877A1 patent drawing

AI summary

An RFID sensing unit for an RFID sensor device includes a columnar substrate (14). An RFID chip (18) having a sensing capability is provided on one end surface (S2) of the substrate (14), and a coupling antenna (16) electrically connected to the RFID sensor chip (18) is provided on the other end surface (S2) of the substrate (14). In this manner, the RFID chip (18) can be spaced from the plane in which the coupling antenna (16) and, in particular, the booster antenna to be inductively coupled to the same are arranged. This improves the performance of the associated RFID sensor device.