Miniaturized RFID Transponder With Metal Zone Field Concentration
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Solution Overview
Problem
Miniaturization of RFID transponders poses challenges in achieving the required power delivery and resonance frequency matching, especially in low-cost, large-scale production, due to the limited antenna size and the need for efficient power pickup from ambient electromagnetic fields.
Innovation Solution
The design incorporates a carrier with a plane and a conductive metal zone surrounding the cavity, forming a capacitor in parallel with the antenna, which enhances the resonance frequency and power pickup by concentrating electromagnetic field lines, while maintaining a simple and cost-effective manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna size is reduced to miniaturize the RFID transponder, then the form factor is improved, but the power pickup capability deteriorates
Solution Approach 1:
The patent introduces a metal zone extending in the direction substantially orthogonal to the antenna plane, adding a third dimension to the structure. This vertical extension allows the metal zone to concentrate electromagnetic field lines without increasing the antenna's planar area, thereby maintaining miniaturization while improving power pickup capability through three-dimensional field manipulation.
Solution Approach 2:
The metal zone acts as an intermediary element between the ambient electromagnetic field and the miniaturized antenna. It concentrates and redirects electromagnetic field lines toward the antenna, enabling efficient power transfer despite the reduced antenna size. This intermediary structure resolves the contradiction by decoupling the antenna dimensions from the power pickup effectiveness.
2Volume of moving object
If the antenna size is reduced to miniaturize the RFID transponder, then the form factor is improved, but the flux reception deteriorates
Solution Approach 1:
By extending the metal zone in the direction orthogonal to the antenna plane, the patent creates a three-dimensional structure that captures and concentrates electromagnetic flux without increasing the antenna's two-dimensional footprint. This allows miniaturized transponders to maintain effective flux reception through vertical field concentration rather than horizontal expansion.
Solution Approach 2:
The metal zone is strategically positioned and shaped to concentrate electromagnetic field lines specifically at the antenna location. This localized field enhancement ensures that the miniaturized antenna receives sufficient flux despite its small size, applying the principle of making different parts of the structure serve different functions - the metal zone for field concentration and the antenna for signal reception.
3Reliability
If additional structures are added to enhance resonance frequency and power pickup, then the performance is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent combines the resonant circuit elements (antenna and capacitor) with the metal zone into a single integrated structure. The metal zone serves dual functions: concentrating electromagnetic field lines for improved power pickup and acting as part of the resonant circuit for frequency matching. This merging of functions reduces the number of separate components and simplifies manufacturing while maintaining performance.
Solution Approach 2:
The metal zone is designed to perform multiple functions simultaneously: it concentrates electromagnetic field lines, participates in the resonant circuit, and provides structural support. This multi-functionality eliminates the need for separate components for each function, thereby improving resonance frequency matching and power pickup without increasing manufacturing complexity.
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 allows for effective communication at the desired frequency with enhanced power delivery, even in small form factors, such as a quarter or fifth of the standard ID-1 format, without compromising the antenna's flux reception, thus addressing the power and resonance challenges in miniaturized RFID transponders.
Implementation Method 1
The RF microcircuit (also referred to as the RF chip) and the antenna together form a resonant circuit... the resonant circuit uses the antenna to draw the power it needs from the electromagnetic field emitted by such a station
Implementation Method 2
The input parasitic impedance of the RF circuit is conventionally likened to the combination of a resistor and a capacitor, connected in parallel... plates made of a conductive material being formed on each of the sides of the carrier facing one another so as to form a capacitor connected in parallel with the antenna
Implementation Method 3
the antenna must deliver enough power within the ambient electromagnetic field to supply power to the RF circuit, at the resonance frequency. The power picked up by an antenna depends on the amplitude of the electromagnetic field and the cross section of the antenna
Implementation Method 4
an annular metal zone... capable of concentrating field lines toward the interior of the turn
Data Source
AI summary
Disclosed is an electronic entity having a transponder which includes a body provided with a recess and, inside the recess, a transponder including a mounting supporting an antenna formed by at least one turn running along the contour of the module and a microcircuit, the antenna and microcircuit being connected to one another, plates of conductive material being formed on each of the surfaces facing one another, covering 60-90% of the surface defined by the one or more turns of the antenna, forming a capacitor connected in parallel on the antenna, and the body including an annular metal area, the inner contour of which projects into the plane of the mounting surrounds the mounting and is suitable for concentrating the field lines toward the inside of the turn, the capacitor defining, with the antenna and the microcircuit, a given resonance frequency substantially equal to the frequency of an external reader.