Remote-Powered Contactless Card With Variable-Capacitance Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current contactless card manufacturing methods cause significant inaccuracies in antenna capacitance and resonance frequency, leading to improper tuning with terminals and affecting data demodulation quality.
Innovation Solution
An electronic device with a variable-capacitance capacitive element adjusts its capacitance iteratively to maximize the instantaneous electric power received from an antenna, using a capacitive element with a digital-to-analog converter to fine-tune the resonance frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current contactless card manufacturing methods are used, then production is simple and fast, but the capacitance of the antennas has significant inaccuracy leading to incorrect resonance frequency
Solution Approach 1:
The patent applies the dynamics principle by making the capacitance value adjustable and variable rather than fixed. The electronic device includes a control circuit that can dynamically modify the capacitance of the capacitive element connected to the antenna, allowing the resonance frequency to be tuned after manufacturing. This resolves the contradiction by enabling precise capacitance control without requiring extremely precise manufacturing processes.
Solution Approach 2:
The patent applies parameter changes by modifying the electrical parameters (capacitance) of the antenna system after manufacturing. The control circuit measures the actual resonance frequency and adjusts the capacitance parameter to achieve the desired resonance frequency, thereby improving manufacturing precision outcomes without increasing manufacturing complexity.
2Reliability
If the contactless card is not correctly tuned with the terminal, then manufacturing is easier, but the quality of data demodulation deteriorates
Solution Approach 1:
The patent applies self-service by implementing an automatic tuning system where the electronic device independently measures its own resonance frequency and adjusts its capacitance without external intervention. The control circuit autonomously optimizes the tuning between the contactless card and terminal, ensuring high data demodulation quality while eliminating the need for manual tuning operations.
Solution Approach 2:
The patent applies feedback by creating a closed-loop tuning system. The control circuit measures the resonance frequency (feedback signal) and uses this information to adjust the capacitance accordingly. This feedback mechanism ensures reliable data demodulation quality while automating the tuning process, making it easy to operate.
3Power
If the resonance frequency is not optimized, then device complexity is reduced, but the amplitude of received signal decreases affecting operating performance
Solution Approach 1:
The patent applies dynamics by implementing a variable capacitance system that can be adjusted to optimize resonance frequency. The electronic device dynamically modifies the capacitance value to maximize the received signal amplitude, ensuring optimal power transfer between the terminal and contactless card without requiring overly complex fixed-precision manufacturing.
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
Ensures optimal resonance with the terminal, enhancing data demodulation performance by maximizing the amplitude of the received signal.
Implementation Method 1
The terminal emits a magnetic field which is captured by an antenna of the telepowered contactless card
Implementation Method 2
the resonance frequency of the assembly comprising the contactless card and the terminal is close or equal to the frequency of the field emitted by the terminal
Data Source
AI summary
In an embodiment an electronic device includes a first electronic circuit having a capacitive element with a variable capacitance, wherein the first electronic circuit is configured to couple the capacitive element to an antenna, to measure, by successive iterations, a first analog signal representative of a variation of an instantaneous electric power received by the antenna or representative of the instantaneous electric power received by the antenna and to modify the capacitance of the capacitive element until an amplitude of the instantaneous electric power received by the antenna is a maximum, wherein the antenna is configured to capture an amplitude-modulated electromagnetic field.