Dual RF Input Envelope Tracking Power Amplifier with Enhanced Load Modulation for Power-Efficiency-Linearity...

Area of Science:

• Electrical Engineering
• Radio Frequency Engineering
• Semiconductor Devices

Background:

• Envelope tracking (ET) power amplifiers (PAs) are crucial for modern wireless communication.
• Conventional ET PAs face challenges with high peak-to-average ratio (PAPR) signals.
• Load modulation (LM) offers a method to improve PA performance.

Purpose of the Study:

• To develop an optimized driving strategy for a dual RF input envelope tracking power amplifier (ET PA) that utilizes load modulation (LM).
• To enhance the efficiency, output power, and linearity of GaN HEMT-based PAs under dynamic signal conditions.
• To improve performance for signals with high PAPR.

Main Methods:

• A dual RF input architecture enabling dynamic load modulation was designed and implemented.
• A GaN HEMT-based LM-ET PA was characterized under pulsed excitation with varying load modulation conditions.
• Control parameters were optimized to create a shaping function for amplitude and phase control of an auxiliary amplifier.

Main Results:

• The proposed dual RF input GaN-based LM-ET PA demonstrated improved efficiency and linearity compared to a conventional ET PA.
• Performance enhancements were observed specifically when tested with high PAPR signals at 3.6 GHz.
• The optimized strategy effectively extended conventional ET supply modulation.

Conclusions:

• The dual RF input LM-ET PA strategy offers a significant performance improvement over conventional ET PAs for challenging signal types.
• This approach provides a viable solution for enhancing the efficiency and linearity of PAs in advanced wireless systems.
• Dynamic load modulation integrated with envelope tracking is a promising technique for future PA designs.