PIM Compensation Circuit for Dynamic RF Interference Cancellation
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Solution Overview
Problem
Current methods for canceling Passive InterModulation (PIM) emissions at the RF antenna port are inadequate, particularly in multi-carrier or multi-band wireless communication devices, as they fail to dynamically track and compensate for time-varying PIM interference, leading to interference with other RF antenna ports and co-located devices, and are limited to Frequency Division Duplex (FDD) systems.
Innovation Solution
A method and system that dynamically and adaptively cancel PIM products on the RF transmission path using a compensation circuit with a PIM estimator, modulator, and RF couplers, generating a PIM estimate signal and modulating it to specific frequencies to counteract PIM interference, effectively reducing emissions across both FDD and Time Division Duplex (TDD) systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current methods for canceling PIM emissions are used, then PIM interference is reduced in FDD systems, but the methods fail to dynamically track and compensate for time-varying PIM interference in multi-carrier or multi-band devices
Solution Approach 1:
The patent implements dynamic tracking of PIM interference by continuously monitoring the RF transmission path and adapting the cancellation signal in real-time. The system uses variable coefficients and time-varying models to follow changes in PIM characteristics, enabling effective compensation in multi-carrier and multi-band TDD systems where PIM varies over time and frequency.
Solution Approach 2:
The patent creates a universal PIM cancellation apparatus that functions across multiple system types (FDD and TDD), multiple carriers, and multiple frequency bands. The cancellation signal generation mechanism is designed to be frequency-agnostic and adaptable to different modulation schemes, making it universally applicable to modern multi-standard wireless communication devices.
2Object-affected harmful factors
If current PIM cancellation methods are used, then some PIM interference is reduced, but interference with other RF antenna ports and co-located devices persists
Solution Approach 1:
The patent extracts and separately processes different PIM interference components generated by the transmission path. By identifying and isolating specific PIM products at different frequency locations, the system can apply targeted cancellation signals to each interference source, preventing cross-interference between different RF ports and co-located devices.
Solution Approach 2:
The patent introduces an intermediary cancellation signal path that generates anti-phase signals to neutralize PIM interference before it reaches other RF antenna ports. This intermediary mechanism acts as a mediator between the PIM source and vulnerable receivers, preventing harmful interactions without modifying the original transmission signal.
3Reliability
If complex PIM compensation circuits are implemented, then PIM interference is better suppressed, but device complexity increases
Solution Approach 1:
The patent segments the PIM cancellation function into distinct modular components: PIM detection unit, cancellation signal generation unit, coefficient adaptation unit, and RF coupling elements. This segmentation allows each component to be optimized independently and simplifies implementation while maintaining effective suppression across multiple carriers and bands.
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 effectively suppresses time-varying PIM interference at the RF antenna port, reducing unwanted emissions and interference with other devices, and is applicable to both FDD and TDD systems, improving product yield and reducing field service requirements.
Implementation Method 1
a modulator (160) connected to the PIM estimator (150) and configured to generate a modulated PIM estimate signal by modulating the PIM estimate signal to frequencies corresponding to the PIM interference
Implementation Method 2
a Radio Frequency, RF coupler (170), connected to the modulator (160) and configured to compensate for the PIM interference on the transmission path by coupling the modulated PIM estimate signal to a RF signal from the transmission path
Data Source
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AI summary
A wireless communication device is provided. The wireless communication device comprises a transceiver; an antenna connected to the transceiver through a transmission path; and a compensation circuit configured to or operative to compensate for a passive intermodulation (PIM) interference on the transmission path, the compensation circuit generating a PIM estimate signal based on a transmit signal and a PIM error signal.