Modular Power Amplifier Sections for Back-Off Efficiency and Bandwidth
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Solution Overview
Problem
Existing power amplifier systems face limitations in achieving high efficiency and wide bandwidth due to the need for all modules to have the same efficiency curve, especially at backed-off operations, which is challenging with Doherty/Chireix-type combination networks, and pure combination methods require all chips to have good efficiency over the entire input signal amplitude range.
Innovation Solution
A modular power amplifier system with multiple sections, where the first section acts as a 'seed' for the lowest input signal amplitudes and subsequent sections perform efficient power addition and combination, allowing each module to operate within a specific amplitude range, reducing the impedance difference and enabling scalable power output with high efficiency across a wide bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Doherty/Chireix-type combination networks are used to improve efficiency at backed-off operations, then efficiency is improved, but device complexity increases and bandwidth is limited
Solution Approach 1:
The amplifier system is divided into multiple independent amplifier modules, each capable of operating efficiently at backed-off conditions. These modules are segmented to handle different portions of the input signal amplitude range, with each module maintaining good efficiency independently rather than requiring complex interaction networks.
Solution Approach 2:
Multiple amplifier modules are combined in parallel to achieve higher total output power while maintaining efficiency. The combining process allows each module to operate independently at its optimal efficiency point, avoiding the need for complex Doherty/Chireix interaction networks while achieving scalable power output.
2Power
If pure combination methods are used to combine multiple chips, then power scalability is achieved, but all chips must have the same efficiency curve shape which limits design flexibility
Solution Approach 1:
The amplifier modules are designed with universal characteristics that allow them to function independently across different operating conditions. Each module is universally capable of maintaining good efficiency over a wide input signal amplitude range, allowing flexible combination configurations without requiring matching efficiency curves.
Solution Approach 2:
The system allows different amplifier modules to have different operating parameters including different efficiency curves, transistor sizes, and impedance characteristics. This parameter diversity enables design flexibility while maintaining overall system efficiency through proper module selection and combination.
3Loss of energy
If Doherty/Chireix-type networks are used with specific transistor sizes for optimal efficiency, then efficiency is improved, but bandwidth decreases and ripple increases
Solution Approach 1:
The system dynamically selects and activates appropriate amplifier modules based on the current input signal amplitude. This dynamic operation allows the system to maintain optimal efficiency across different signal levels while preserving bandwidth, as each module can be optimized for its specific operating range without compromising overall system bandwidth.
4Power
If multiple amplifier modules are combined to achieve higher power, then power output is improved, but maintaining good efficiency at backed-off operations becomes more difficult
Solution Approach 1:
The total power amplification task is segmented across multiple independent modules, each designed to maintain good efficiency at backed-off conditions. By segmenting the power handling function, each module operates at a lower individual power level where it can maintain optimal efficiency, while the combined system achieves high total power output.
Data Source
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AI summary
A modular power amplifier system (100) and an electronic device comprising the modular power amplifier system are disclosed. The modular power amplifier system (100) comprises a plurality of amplifier modules (111, 121, 131, 132, 1i1). The plurality of amplifier modules are arranged into a number of sections comprising a first section which comprises a first amplifier module (111) configured to receive the input signal within a first amplitude range and provide an output signal having a first output power (P1); a second section which comprises a second amplifier module (121) configured to receive the input signal within a second amplitude range and provide an output signal having a second output power (P2); and an i-th section which comprises multiple amplifier modules (1i1), each being configured to receive the input signal within a certain amplitude range and provide an output signal having a certain output power (Pi). The output signals of the amplifier modules are combined to provide output signals with scalable output power.