RFID Tag Self-Tuning Circuit Impedance Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
RFID tags face challenges in optimizing signal strength due to internal or external factors like distance and nearby objects, which affects data communication efficiency, particularly because existing self-tuning circuits are hindered by voltage limiters that prevent optimal impedance tuning.
Innovation Solution
The RFID tag incorporates a self-tuning circuit with a limiter controller that temporarily deactivates the voltage limiter during a self-tuning phase to adjust impedance, ensuring optimal signal strength before data communication, using a method that includes a current measuring circuit and transistors to manage the limiter's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a voltage limiter is used to protect the RFID tag circuit, then circuit reliability is improved, but impedance tuning capability deteriorates
Solution Approach 1:
The patent applies preliminary action by performing impedance tuning before the voltage limiter is activated during data communication. The self-tuning phase occurs first to optimize impedance matching, then the voltage limiter is enabled for subsequent operations. This temporal sequencing allows both impedance optimization and circuit protection to achieve their respective goals without interference.
2Productivity
If impedance tuning is optimized for maximum signal strength, then communication efficiency is improved, but voltage control capability deteriorates
Solution Approach 1:
The patent segments the operation into distinct phases: a self-tuning phase for impedance optimization and a data communication phase for voltage-controlled operations. During the self-tuning phase, the voltage limiter is disabled to allow full impedance adjustment range. During the data communication phase, the voltage limiter is enabled to provide precise voltage control. This segmentation resolves the contradiction by allowing each function to operate optimally in its designated phase.
Data Source
Figure 1~3
Figure 4~5
AI summary
A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna port to receive an input AC signal and a self-tuning circuit coupled with the antenna port to optimize signal strength of the input AC signal during a self-tuning phase. The RFID tag further includes an AC limiter configured to limit the voltage of the input AC signal to a preconfigured limit and a limiter controller configured to disable the AC limiter during the self-tuning phase and re-enable the AC limiter after the self-tuning phase. The self-tuning phase occurs prior to the data communication period in which the data stored in the RFID tag is transmitted back to a reader.