Envelope Tracking Voltage Generation for RF Amplifier Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile communication devices face increased power consumption and thermal dissipation due to higher output power requirements for RF signals, compromising performance and user experience, despite the use of envelope tracking (ET) power amplifiers which aim to improve efficiency.
Innovation Solution
A voltage generation circuit is introduced in the ET amplifier apparatus to selectively provide supply voltages based on a time-variant target voltage envelope, improving the efficiency and linearity of the amplifier by dynamically adjusting voltages to match instantaneous power requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher output power is used to achieve higher data rates, then communication performance is improved, but power consumption and thermal dissipation increase
Solution Approach 1:
The patent implements dynamic supply voltage adjustment in the power amplifier, where the supply voltage is continuously varied to track the envelope of the modulated signal. This dynamic operation allows the amplifier to maintain high efficiency across different output power levels by operating in an optimized region, rather than at a fixed bias point, thereby reducing overall power consumption while maintaining high data rate capability
Solution Approach 2:
The patent changes the supply voltage parameter dynamically based on the signal envelope. By adjusting the supply voltage to match the instantaneous power requirements, the system achieves better efficiency without sacrificing output power capability, thus resolving the contradiction between high data rate performance and power consumption
2Productivity
If higher output power is used to achieve higher data rates, then communication performance is improved, but thermal dissipation increases
Solution Approach 1:
The dynamic supply voltage tracking reduces the time the power amplifier spends in high-power states, thereby reducing average thermal dissipation. The amplifier quickly responds to envelope changes and returns to low-power states, preventing excessive heat accumulation while maintaining the capability for high data rate transmission
Solution Approach 2:
The envelope tracking operates in a periodic manner following the signal envelope, where the supply voltage is increased only when needed and reduced during low-power intervals. This periodic adjustment pattern reduces average thermal dissipation while maintaining peak performance capability for high data rates
3Use of energy by moving object
If time-variant voltages are constantly adjusted to maintain amplifier efficiency, then power efficiency is improved, but device complexity increases
Solution Approach 1:
The patent employs feedback mechanisms where the envelope detector monitors the modulated signal and provides control voltage to the power amplifier. This closed-loop feedback automatically adjusts the supply voltage to track the signal envelope, maintaining high efficiency without requiring complex external control circuitry, thus managing device complexity while achieving constant efficiency optimization
Data Source
AI summary
A voltage generation circuit and related envelope tracking (ET) amplifier apparatus is provided. In examples discussed herein, a voltage generation circuit can be provided in an ET amplifier apparatus to provide a supply voltage to a voltage amplifier(s) that is configured to generate an ET voltage for an amplifier circuit(s). In a non-limiting example, the voltage amplifier(s) receives an ET target voltage signal corresponding to a time-variant target voltage envelope and generates the ET voltage conforming to the time-variant target voltage envelope. The voltage generation circuit is configured to generate one or more supply voltages and selectively provide one of the supply voltages to the voltage amplifier(s) in accordance to the time-variant target voltage envelope. By selectively providing the supply voltage based on the time-variant target voltage envelope, it may be possible to improve efficiency of the voltage amplifier, thus helping to improve efficiency and linearity of the amplifier circuit(s).