Adaptive RFID Carrier Cancellation Feedback Loop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
RFID systems face challenges in distinguishing the tag signal from the strong carrier signal and phase noise, especially in environments with reflective objects, which limits reader sensitivity and range.
Innovation Solution
An adaptive closed-loop feedback system dynamically detects the carrier signal and phase noise at the reader's input, using DC components to cancel out the carrier and associated noise, thereby improving signal extraction and reducing interference from reflective objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the reader transmits a strong carrier signal to power passive tags, then tag power supply is sufficient, but carrier signal and phase noise interfere with tag signal detection
Solution Approach 1:
The patent extracts and removes the carrier signal and phase noise components from the received signal using signal processing techniques. By separating the harmful carrier components from the useful tag signal, the system maintains sufficient power transmission while eliminating interference that degrades detection precision.
Solution Approach 2:
The patent introduces an intermediary signal processing stage that processes the received signal between reception and detection. This intermediary processing removes carrier and phase noise components, allowing the system to maintain strong carrier transmission for power while achieving clean tag signal detection.
2Object-generated harmful factors
If traditional carrier cancellation methods are used, then some carrier interference is reduced, but they fail to remove variable reflected carrier signal from moving objects
Solution Approach 1:
The patent employs dynamic carrier cancellation that continuously adapts to changing environmental conditions. The system monitors and tracks variable reflected carrier signals from moving objects in real-time, adjusting cancellation parameters dynamically to maintain effectiveness despite environmental changes and object movement.
Solution Approach 2:
The patent implements a feedback mechanism that continuously monitors the received signal for carrier components and adjusts the cancellation process accordingly. This feedback loop enables the system to adapt to variable reflected signals from moving objects, maintaining effective interference reduction across changing environmental conditions.
3Length of stationary object
If the reader increases transmission power to extend range, then communication distance increases, but carrier cross-talk and phase noise increase proportionally
Solution Approach 1:
The patent extracts and removes carrier cross-talk and phase noise components from the received signal regardless of transmission power level. This allows the system to increase transmission power for extended range while maintaining signal quality by eliminating the proportionally increased interference through active carrier removal.
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 RFID reader sensitivity and dynamic range by removing carrier cross-talk and non-modulated backscatter, allowing for increased low noise amplifier gain and improved communication link budgets.
Implementation Method 1
dynamically detects the magnitude of the carrier signal at the input to the reader by monitoring the carrier content from the reader and use this information to not only cancel out a majority of the carrier itself
Implementation Method 2
cancel out more of the carrier signal itself as well as much of its associated phase noise
Implementation Method 3
allowing for increased low noise amplifier gain
Data Source
AI summary
Systems and methods for adaptive cancellation of carrier content includes receiving a signal, adaptively detecting an amount of carrier content in the received signal, generating a feedback signal for canceling out the carrier content in the incoming signal, and introducing the feedback signal for canceling out a majority of carrier content in the signal being received.