Supply Modulation Transmitter Switch Network for RF Linearity
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Solution Overview
Problem
Existing RF transmitters face a trade-off between energy efficiency and linearity, particularly in mobile devices, making it challenging to transmit data carrying RF signals with both high efficiency and high linearity.
Innovation Solution
A multi-output power supply system with a multi-stage pulse shaping network (PSN) and a configuration switch network is employed, which includes a T-network of switches to selectively short passive elements, allowing for efficient power amplification with sufficient linearity, especially for modulation schemes with high peak to average power ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional RF transmitter designs are used, then energy efficiency can be improved, but linearity deteriorates
Solution Approach 1:
The power supply system is divided into multiple independent voltage outputs (first voltage output, second voltage output, third voltage output) that can be independently controlled. This segmentation allows different voltage levels to be applied to different parts of the RF amplifier circuit, enabling efficient power delivery while maintaining signal linearity through selective voltage modulation.
Solution Approach 2:
The system dynamically changes voltage parameters by providing multiple discrete voltage levels (first voltage level, second voltage level, third voltage level) through the multi-output power supply. The pulse shaping network modifies the trajectory of these voltage signals, and switches selectively connect different voltage outputs based on operating conditions, thereby adjusting power delivery parameters to achieve both efficiency and linearity.
2Productivity
If high peak to average power ratio modulation schemes are used, then data transmission capability is improved, but power amplification efficiency deteriorates
Solution Approach 1:
The system employs dynamic voltage control where the multi-output power supply adjusts voltage levels in real-time based on the modulation scheme requirements. The pulse shaping network dynamically modifies voltage trajectories, and switches reconfigure connections between different voltage outputs according to instantaneous power demands, enabling efficient handling of high peak-to-average power ratio signals.
Solution Approach 2:
The pulse shaping network applies periodic modulation to the voltage outputs, shaping the voltage trajectories in synchronization with the modulation scheme. This periodic action allows the power amplifier to operate efficiently during peak periods while maintaining linearity during average power periods, thereby supporting high data transmission capability without excessive energy loss.
3Adaptability or versatility
If multiple RF amplifiers are accommodated, then system versatility is improved, but device complexity increases
Solution Approach 1:
The multi-output power supply system provides universal power delivery capability by generating multiple voltage outputs that can serve different RF amplifiers with different power requirements. The same power supply architecture supports multiple amplifiers through selective switching, eliminating the need for separate power supplies for each amplifier and thereby reducing overall system complexity.
Solution Approach 2:
The configuration switch network acts as an intermediary between the multi-output power supply and multiple RF amplifiers. These switches selectively connect appropriate voltage outputs to specific amplifiers based on their requirements, simplifying the power distribution architecture by providing a centralized control mechanism rather than requiring dedicated connections for each amplifier.
Data Source
AI summary
A power supply modulator circuit includes a multi-output power supply that generates multiple power output signals; at least one power modulator circuit generates a modulated power output signal from the multiple power output signals of the multi-output power supply; at least one pulse shaping network (PSN) having at least one passive element, the PSN configured to shape the modulated power output signal; at least one power amplifier coupled to receive the modulated power signal; and a switching network having a plurality of switches to create or modify power signal paths from the at least one power modulator circuit to the at least one power amplifier.