Wire Capacitor for RF Transponder Delamination Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radiofrequency transponder devices, such as contactless smart cards and electronic passports, face manufacturing complexities and performance issues due to the use of double-sided etching for capacitors and antennas, leading to delamination risks and inefficiencies in radiofrequency coupling.
Innovation Solution
A method of manufacturing radiofrequency devices using a wired capacitor with conductive wire plates formed on a substrate, where the capacitor plates are either separate from or integrated with the antenna turns, allowing for improved radiofrequency performance and simplified production through a single technique like embroidery or inlay, avoiding delamination and reducing surface area requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If double-sided etching is used for capacitor and antenna, then capacitor functionality is achieved, but manufacturing complexity increases and delamination risk occurs
Solution Approach 1:
The patent combines the capacitor plate and antenna into a single integrated structure formed by the same wire, eliminating the need for separate manufacturing processes. The wire forms both the capacitor plates (through parallel sections) and the antenna (through loop sections) in one continuous structure, thereby eliminating delamination risks between separate components and simplifying manufacturing.
Solution Approach 2:
The wire structure serves multiple functions simultaneously: it forms the capacitor plates for frequency tuning, creates the antenna loop for RF coupling, and provides mechanical support. This multi-functional design eliminates the need for separate capacitor and antenna components, reducing manufacturing complexity and eliminating interface delamination issues.
2Reliability
If wide antenna turns are used for RF coupling, then radiofrequency performance is improved, but delamination risk increases due to poor adhesion
Solution Approach 1:
The patent merges the capacitor and antenna into a single wire structure where the same wire forms both components. This integration eliminates the interface between separate components, removing the delamination risk entirely while maintaining adequate RF performance through optimized wire geometry and positioning.
Solution Approach 2:
The wire is positioned and configured with specific local characteristics: parallel sections for capacitor plates are placed close together for high capacitance, while loop sections for the antenna are positioned to maximize RF coupling. The wire diameter and spacing are optimized locally to achieve both mechanical stability and RF performance without requiring excessive width that would cause adhesion problems.
3Ease of manufacture
If separate capacitor plates are used, then capacitor functionality is achieved, but manufacturing steps increase
Solution Approach 1:
The patent merges the capacitor plates and antenna into a single continuous wire structure. The wire forms parallel sections that serve as capacitor plates and loop sections that serve as the antenna, all in one integrated component. This eliminates multiple manufacturing steps for assembling separate components and reduces the total number of parts.
Solution Approach 2:
The single wire structure performs multiple functions: it creates the capacitor plates through its parallel sections, forms the antenna loop through its circular sections, and provides mechanical support. This universal design eliminates the need for separate capacitor and antenna components, simplifying manufacturing while maintaining 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
This approach enhances radiofrequency performance, simplifies the manufacturing process, and prevents delamination, while allowing for better radiofrequency coupling with reduced antenna loop size and surface area, thus improving the overall efficiency and reliability of radiofrequency transponders.
Implementation Method 1
Device comprising a wire capacitor (C) in particular by inlay or embroidery and connected or intended to be connected to a radiofrequency antenna (A) with which it forms a resonant circuit
Implementation Method 2
the antenna and the capacitor generally form a resonant circuit
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
The invention relates to a radio frequency device including an antenna connected to a capacitor. Said capacitor includes first (24, 44) and second (25, 45) conductive plates that are opposite each other and separated by an insulator (41). At least one of said first and second plates (24, 44) is formed of a plurality of wire capacitor portions (24N, 25N, 44N). Said radio frequency device is different in that the antenna (A) and at least one capacitor plate (C) are formed with wire portions guidably placed on a substrate.