Supply Modulator With ET/APT Tracking for PA Power Efficiency
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Solution Overview
Problem
Wireless communication devices face inefficiencies in power amplifier performance due to high peak-to-average power ratio (PAPR) and high bandwidth, leading to decreased power efficiency when using conventional power supply methods.
Innovation Solution
A supply modulator that operates in both envelope tracking (ET) and average power tracking (APT) modes, utilizing a linear regulator, switching regulator, and single inductor multiple output (SIMO) converter to dynamically adjust output voltage and provide efficient power supply to the power amplifier, with a main controller managing the tracking mode and controlling the components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional power supply methods are used for power amplifiers in wireless communication devices, then the device structure remains simple, but power efficiency decreases due to high peak-to-average power ratio (PAPR) and high bandwidth
Solution Approach 1:
The power supply system is segmented into multiple independent modules: a switching regulator for bulk power conversion, a linear regulator for precise voltage control, and a capacitor bank for energy storage. Each module operates independently to address specific requirements, allowing the system to achieve high power efficiency without excessive overall complexity.
Solution Approach 2:
The power supply system dynamically switches between different operating modes (ET mode and APT mode) based on signal conditions. The controller adjusts the operation of each regulator and the capacitor charging/discharging cycles in real-time to match the instantaneous power requirements, optimizing efficiency while managing complexity through adaptive control.
2Use of energy by moving object
If a single inductor multiple output (SIMO) converter is used to provide power supply voltage, then power efficiency improves, but the device complexity increases
Solution Approach 1:
The SIMO converter merges multiple output functions into a single inductor-based circuit structure. This shared inductor serves multiple voltage output requirements simultaneously, reducing the total component count and improving power efficiency while maintaining manageable complexity through functional integration.
Solution Approach 2:
The single inductor in the SIMO converter performs multiple functions: it supports both ET mode operation (providing power supply voltage to the linear regulator) and APT mode operation (working with the switching regulator). This multi-functionality reduces overall system complexity while achieving improved power efficiency across different operating conditions.
3Speed
If rapid voltage changes are enabled for fast modulation response, then modulation operation performance improves, but signal distortion may occur
Solution Approach 1:
Capacitors are pre-charged to appropriate voltage levels before rapid voltage changes are required. The switching regulator and controller work together to prepare the capacitor bank in advance, ensuring that when fast voltage transitions are needed, the capacitors can immediately discharge or charge without causing signal distortion, thus maintaining both speed and signal quality.
Solution Approach 2:
The linear regulator acts as an intermediary between the switching regulator/capacitor bank and the power amplifier. It smooths out rapid voltage changes by filtering high-frequency components while maintaining the overall voltage trajectory, enabling fast response without introducing signal distortion to the final output.
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
The solution improves power use efficiency and modulation operation performance by enabling rapid voltage changes and preventing signal distortion, enhancing overall power amplifier efficiency across varying communication modes.
Implementation Method 1
a first capacitor connected with a power supply terminal of the linear regulator
Implementation Method 2
a second capacitor selectively connected with an output terminal of the linear regulator through a first switch
Data Source
AI summary
A supply modulator includes a linear regulator that generates an output voltage in an envelope tracking mode. A switching regulator operates with the linear regulator to generate the output voltage in the envelope tracking mode and to selectively generate the output voltage in an average power tracking mode. A single inductor multiple output converter operates selectively with the switching regulator to generate the output voltage in the average power tracking mode, operates to provide a power supply voltage to the linear regulator in the envelope tracking mode, and includes a first capacitor connected with a power supply terminal of the linear regulator and a second capacitor selectively connected with an output terminal of the linear regulator through a first switch. A main controller decides a tracking mode to be executed by the supply modulator.