Multi-Carrier Power Tracking for Efficient RF Power Amplifiers
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Solution Overview
Problem
Power amplifiers in wireless devices face inefficiencies when handling multiple transmit signals simultaneously, leading to wasted power and potential intermodulation distortion due to the need for high power supply voltages that exceed the envelope of the output RF signals.
Innovation Solution
A power tracking system that generates a supply voltage based on the in-phase and quadrature components of multiple transmit signals, allowing a single power amplifier to efficiently amplify multiple signals by tracking the envelope of the output RF signal, thereby reducing circuit complexity and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a high power supply voltage is used to handle multiple transmit signals simultaneously, then the power amplifier can provide sufficient transmit power, but power waste increases and power-added efficiency decreases
Solution Approach 1:
The patent implements dynamic power supply voltage adjustment by introducing a power tracking mechanism that continuously monitors the envelope of the combined RF signal and adjusts the power supply voltage in real-time. This allows the power amplifier to operate with optimal power supply voltage that matches the instantaneous signal requirements, rather than using a static high voltage that causes power waste during low-signal periods.
Solution Approach 2:
The patent employs feedback through an envelope detector that monitors the output signal envelope and feeds this information back to the power supply control circuitry. This feedback mechanism enables the power supply voltage to track the signal envelope, ensuring that the power amplifier receives exactly the power it needs at any given moment, thereby improving power-added efficiency while maintaining sufficient transmit power capability.
2Power
If a high power supply voltage is used to handle multiple transmit signals simultaneously, then the power amplifier can provide sufficient transmit power, but power-added efficiency decreases
Solution Approach 1:
The patent implements dynamic power supply voltage adjustment by introducing a power tracking mechanism that continuously monitors the envelope of the combined RF signal and adjusts the power supply voltage in real-time. This allows the power amplifier to operate with optimal power supply voltage that matches the instantaneous signal requirements, rather than using a static high voltage that causes power waste during low-signal periods.
Solution Approach 2:
The patent employs feedback through an envelope detector that monitors the output signal envelope and feeds this information back to the power supply control circuitry. This feedback mechanism enables the power supply voltage to track the signal envelope, ensuring that the power amplifier receives exactly the power it needs at any given moment, thereby improving power-added efficiency while maintaining sufficient transmit power capability.
3Adaptability or versatility
If multiple transmit signals are processed simultaneously, then wireless communication capability is enhanced, but circuit complexity increases
Solution Approach 1:
The patent merges multiple transmit signals into a single combined RF signal that is processed by a single power amplifier. By combining the signals at the RF stage and using one power amplifier instead of multiple separate amplifiers, the circuit complexity is reduced while maintaining the capability to transmit multiple signals simultaneously through carrier aggregation or multi-carrier techniques.
Solution Approach 2:
The patent makes a single power amplifier circuit capable of handling multiple transmit signals by designing it to process a combined multi-carrier RF signal. This universal approach allows one power amplifier to perform the function that would otherwise require multiple amplifiers, thereby reducing circuit complexity while preserving enhanced wireless communication capability.
Data Source
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AI summary
Techniques for generating a power tracking supply voltage for a circuit (e.g., a power amplifier) are disclosed. The circuit may process multiple transmit signals being sent simultaneously on multiple carriers at different frequencies. In one exemplary design, an apparatus includes a power tracker and a power supply generator. The power tracker determines a power tracking signal based on a plurality of polar modulated transmit signals being sent simultaneously. The power supply generator generates a power supply voltage based on the power tracking signal. The apparatus may further include a power amplifier (PA) that amplifies a modulated radio frequency (RF) signal based on the power supply voltage and provides an output RF signal.