Multi-mode Power Amplifier Phase Matching via Segmented Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-mode power amplifiers experience reduced efficiency and degraded linearity at back-off power levels, leading to phase discontinuity when switching between power modes, which degrades error vector magnitude (EVM) and reduces battery life in mobile devices.
Innovation Solution
A multi-mode power amplifier with parallel amplification paths, including a first path with a common-base input stage and a common-emitter output stage, and a second path with a common-emitter input stage, allowing for phase matching between power modes without phase discontinuity, reducing DC power consumption, and eliminating the need for phase shifting circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional multi-mode power amplifiers switch between power modes, then power levels can be adjusted, but phase discontinuity occurs which degrades EVM
Solution Approach 1:
The power amplifier is divided into multiple parallel amplification paths (first and second paths), each capable of operating independently at different power levels. This segmentation allows the system to switch between power modes by activating different paths while maintaining phase coherence, thereby avoiding phase discontinuity and EVM degradation.
Solution Approach 2:
The patent introduces a new dimension of control by using parallel amplification paths with different stage configurations (common-base/common-emitter vs. common-emitter only). This dimensional approach enables power mode switching without relying on traditional single-path amplification, thus maintaining phase continuity across different power levels.
2Use of energy by moving object
If power amplifiers operate at back-off power levels, then power consumption is reduced, but efficiency and linearity deteriorate
Solution Approach 1:
By segmenting the amplification function into parallel paths optimized for different power levels, the system can operate each path at its optimal efficiency point. The first path (common-base/common-emitter) is optimized for higher power operation, while the second path (common-emitter) handles lower power levels, preventing the efficiency and linearity degradation that occurs in conventional single-path amplifiers at back-off levels.
Solution Approach 2:
Each amplification path is designed with specific local characteristics (different stage configurations) suited for its intended operating range. This local optimization ensures that regardless of the overall power level, the active path operates with high efficiency and linearity, eliminating the back-off penalty suffered by conventional amplifiers.
3Reliability
If phase shifting circuits are added to maintain phase matching, then phase discontinuity is corrected, but device complexity increases
Solution Approach 1:
Instead of adding complex phase shifting circuits to a single amplification path, the patent segments the amplification function into parallel paths that are inherently phase-matched through their complementary stage configurations. This eliminates the need for additional phase correction circuitry, maintaining phase matching while avoiding increased complexity.
Solution Approach 2:
The patent uses a simplified approach by copying the essential amplification function across parallel paths with different stage configurations, rather than copying and modifying a single complex path with added phase shifting components. This reduces overall complexity while achieving the same phase matching objective.
Data Source
AI summary
Apparatus and methods for multi-mode power amplifiers are provided herein. In certain configurations, a wireless device includes a multi-mode power amplifier including a plurality of amplification paths electrically connected in parallel with one another. The plurality of amplification paths includes a first amplification path including an input stage of a first stage type and an output stage of a second stage type, and a second amplification path including an output stage of the second stage type. The first stage type provides non-inverting gain and the second stage type provides inverting gain. The wireless device further includes a transceiver that provides a radio frequency signal to the multi-mode power amplifier, and that operates the multi-mode power amplifier in a selected power mode chosen from a plurality of power modes based on selectively activating one or more of the plurality of amplification paths.