RF Power Amplifier Phase Correction for Envelope Tracking Delay
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Solution Overview
Problem
In 5G-NR mobile communication devices, the inherent processing delay in envelope tracking integrated circuits (ETICs) can cause misalignment between the time-variant ET voltage and the time-variant power envelope of RF signals, leading to clipping and distortion of RF signals.
Innovation Solution
A power amplifier circuit is designed with a phase correction circuit that generates a phase correction signal based on the modulated voltage, allowing for phase alignment between the modulated voltage and the time-variant power envelope, thereby improving the efficiency and linearity of the power amplifier circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If envelope tracking integrated circuit (ETIC) is used to generate time-variant voltage to improve power amplifier efficiency, then power amplifier efficiency is improved, but processing delay causes phase misalignment between voltage and power envelope
Solution Approach 1:
The patent applies preliminary action by measuring the RF signal phase in advance before amplification and pre-adjusting the envelope signal phase to compensate for the known processing delay in the ETIC. This allows the system to maintain phase alignment between the modulated voltage and power envelope despite the inherent delay, resolving the contradiction between using ETIC for efficiency improvement and the time loss from processing delay
2Manufacturing precision
If phase correction circuit is added to align modulated voltage with power envelope, then phase alignment and linearity are improved, but device complexity increases
Solution Approach 1:
The patent uses an intermediary approach by introducing a phase correction circuit that acts as a mediator between the ETIC and the power amplifier. This circuit measures the RF signal phase and generates corrected envelope signals to compensate for phase misalignment. The intermediary circuit adds controlled complexity to achieve precise phase alignment and maintain manufacturing precision without excessive system complexity
Data Source
AI summary
A power amplifier circuit supporting phase correction in a radio frequency (RF) signal is disclosed. The power amplifier circuit includes a power amplifier configured to amplify an RF signal based on a modulated voltage. The power amplifier circuit also includes a phase correction circuit configured to generate a phase correction signal based on the modulated voltage to thereby cause a phase change in the RF signal before the RF signal is amplified by the power amplifier. As a result, the modulated voltage and the time-variant power envelope can be better aligned in time and/or phase at the power amplifier circuit to thereby improve efficiency and linearity of the power amplifier circuit.