Power Supply Mode Switching for RF Interference Control
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Solution Overview
Problem
Wireless communications devices face inefficiencies in power supply due to the limitations of pulse width modulation (PWM) and pulse frequency modulation (PFM) methods, particularly at low load currents and in scenarios with multiple operating modes, where PWM efficiency decreases and PFM compromises performance with unpredictable frequency interference.
Innovation Solution
A power switching system that dynamically switches to PWM mode when a transceiver processes low-quality signals or has high power demands, using a PSM utility to determine signal quality and power demand, and autonomously switching between PWM and PFM modes based on pre-set thresholds, ensuring optimal power supply modes for concurrent operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If PFM mode is used to improve efficiency at low load currents, then power efficiency is improved, but electromagnetic interference frequency becomes unpredictable and may interfere with RF circuit operation
Solution Approach 1:
The system dynamically switches between PFM and PWM modes based on real-time operating conditions. The controller monitors load current and signal quality, then adaptively selects the appropriate power supply mode to balance efficiency and EMI characteristics across different operational states.
Solution Approach 2:
The invention changes the operating parameters of the power supply system by switching between two distinct modulation modes (PFM and PWM). Each mode has different characteristic parameters: PFM provides variable frequency for efficiency while PWM provides fixed frequency for EMI control, allowing parameter optimization based on operational needs.
2Object-generated harmful factors
If PWM mode is used to maintain constant switching frequency and reduce EMI, then electromagnetic interference is reduced, but switching efficiency decreases as load current decreases
Solution Approach 1:
The system transitions from static PWM operation to dynamic mode selection, where the controller adjusts the power supply mode based on real-time load conditions. This allows the system to exploit PWM's EMI advantages when needed while switching to PFM for efficiency when load conditions permit.
Solution Approach 2:
The invention modifies the fundamental operating parameters by switching between fixed-frequency PWM and variable-frequency PFM modes. This parameter change enables the system to optimize for either EMI reduction or efficiency depending on the operational context.
3Adaptability or versatility
If PFM mode is used with multiple band/mode combinations, then adaptability to different operating conditions is improved, but performance is compromised in some conditions due to unpredictable frequency interference
Solution Approach 1:
The system implements dynamic mode selection that adapts to different band and mode combinations by monitoring operating conditions in real-time. The controller dynamically determines whether PFM or PWM mode is appropriate for the current RF operational state, ensuring reliable performance across all band/mode combinations.
Solution Approach 2:
The invention incorporates feedback mechanisms where the controller monitors RF circuit operation and load conditions, then uses this information to select the appropriate power supply mode. This feedback loop ensures that EMI from PFM does not interfere with RF circuits while maintaining adaptability to different operating conditions.
Data Source
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AI summary
A method, power switching system, and communications device supply power in a pulse width modulation (PWM) mode to a transceiver whenever the transceiver processes a low quality signal. A power supply mode (PSM) utility/controller determines a quality of a signal that is currently being processed by a transceiver, and when the quality of the signal is less than a pre-set threshold level, the PSM controller triggers the power supply to operate exclusively in the PWM supply mode. However, when the quality of the signal satisfies a preset threshold level, the PSM controller enables the power supply to autonomously switch between the PFM supply mode and the PWM supply mode. In one embodiment, the controller dynamically determines a power demand by the transceiver and when the power demand exceeds a preset threshold demand level, the controller triggers the power supply to operate exclusively in the PWM supply mode.