Multi-Path Linear Power Amplifier for ACPR Error Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-cost and limited scalability of existing linearity power amplifiers, particularly those using feedforward-predistortion systems, which are complex and only support 2-way amplifiers, leading to degraded adjacent channel power ratio (ACPR) when gains of amplifiers differ.
Innovation Solution
A linearity power amplification device with a divider to split input signals into multiple paths, using a combiner to generate output signals with error cancellation, incorporating a main invariable attenuator, power amplifiers, and an error calibration circuit to adjust signal levels and phases, supporting multiple amplifiers and reducing complexity and cost through feedforward and pre-calibration techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a feedforward-predistortion system is used to achieve linearity power amplification, then linearity is improved, but device complexity and cost increase significantly
Solution Approach 1:
The system is divided into multiple independent signal paths (first signal path with main amplifier, second signal path with auxiliary amplifier). Each path processes signals independently and contributes to the overall output, allowing the complex linearity function to be distributed across simpler modular components rather than requiring a single complex predistortion system
Solution Approach 2:
The auxiliary amplifier path serves multiple functions: it provides error signal generation, enables ACPR improvement through gain differentiation, and supports scalable multi-way amplifier configurations. This multi-functional design replaces the need for separate predistortion circuits while achieving linearity improvement
2Device complexity
If the system is designed to support only 2-way amplifiers, then device complexity is reduced, but adaptability and scalability are limited
Solution Approach 1:
The divider is designed to output n first signals (where n≥2), and the combiner is configured to receive n output signals, creating a universal architecture that can accommodate any number of amplifiers. The system structure remains consistent regardless of the number of ways, enabling scalable deployment from 2-way to multi-way configurations without fundamental redesign
Solution Approach 2:
The system allows dynamic configuration of the number of amplifier paths. The divider and combiner are designed with flexible signal routing capabilities that can adapt to different numbers of amplifiers, enabling the system to be configured for 2-way, 3-way, or higher-order amplifier arrangements based on specific application requirements
3Stability of the object's composition
If the gain of auxiliary amplifier is made the same as main amplifier, then signal balance is improved, but matching circuit complexity increases
Solution Approach 1:
The system deliberately uses asymmetric gain configuration where the auxiliary amplifier has a different gain than the main amplifier. This asymmetric design simplifies the matching circuit by eliminating the need for complex gain equalization networks, while the error calibration circuit compensates for the gain difference to maintain overall signal balance and linearity
4Device complexity
If the gain of auxiliary amplifier is made different from main amplifier, then matching circuit complexity is reduced, but adjacent channel power ratio (ACPR) is degraded
Solution Approach 1:
The error calibration circuit functions as a feedback mechanism that monitors the output signals from both amplifiers and adjusts the auxiliary amplifier's contribution to compensate for ACPR degradation. This feedback loop ensures that even with different amplifier gains, the overall system maintains improved ACPR performance by dynamically correcting any distortion components
Data Source
AI summary
A linearity power amplification device is provided. The device comprises a divider, a combiner, n−1 first signal paths, and a second signal path coupled between the divider and the combiner. The first signal path comprises a main invariable attenuator connected to the divider, a first power amplifier connected to the combiner, and a first attenuator and a first shifter coupled between the first power amplifier and the main invariable attenuator. The second signal path comprises a main amplification circuit, and an error calibration circuit.