Adaptive Envelope Tracking Circuit for Noise-Efficiency Balance
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Solution Overview
Problem
Conventional envelope tracking amplifiers face challenges in achieving a balance between power efficiency and noise performance across a wide bandwidth range, as they require high switching frequency for efficiency and low frequency for reduced noise.
Innovation Solution
The implementation of an adaptive switching frequency mechanism in envelope tracking circuits, where a programmable comparator and frequency comparison circuit dynamically adjust the switching frequency to track the envelope tracking frequency, using a switching regulator with PMOS and NMOS transistors and an inductor, to optimize efficiency and noise performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If high switching frequency is used in the switching regulator stage, then power efficiency is improved, but noise performance deteriorates
Solution Approach 1:
The patent implements dynamic adjustment of the switching frequency based on the envelope tracking frequency. The switching frequency is adaptively changed to track the envelope frequency, allowing the system to optimize between efficiency and noise performance under different operating conditions rather than using a fixed high switching frequency
2Object-generated harmful factors
If low switching frequency is used in the switching regulator stage, then noise performance is improved, but power efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts switching frequency based on envelope tracking frequency requirements. When low noise is needed, the switching frequency is reduced; when efficiency is prioritized, the frequency is increased. This dynamic adaptation resolves the static trade-off between noise and efficiency
3Loss of energy
If fixed high switching frequency is used, then efficiency is improved, but adaptability to different envelope tracking frequencies deteriorates
Solution Approach 1:
The switching frequency is made dynamic and adaptive by linking it to the envelope tracking frequency. The system automatically adjusts the switching frequency to match or track the envelope frequency, providing versatility across different operating conditions while maintaining efficiency
Solution Approach 2:
The system uses feedback from the envelope tracking frequency to control the switching regulator's operating frequency. This feedback mechanism enables the switching frequency to automatically adapt to changing envelope conditions, improving both efficiency and versatility
Data Source
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AI summary
The present disclosure includes envelope tracking circuits and methods with adaptive switching frequency. In one embodiment, a circuit comprising an amplifier to receive an envelope tracking signal having an envelope tracking frequency and output voltage and current to a power supply terminal of a power amplifier circuit. A programmable comparator receives an output signal from the amplifier and generates a switching signal having a switching frequency. A switching regulator stage receives the switching signal and outputs a switching current to the power supply terminal. A frequency comparison circuit configures the programmable comparator based on the envelope tracking frequency and the switching frequency so that the switching frequency tracks the envelope tracking frequency.