Internally Harmonic Matched Compact GaN Power Amplifier with 78.5% PAE for 2.45 GHz Wireless Power Transfer Systems.

Area of Science:

• Electrical Engineering
• Materials Science

Background:

• Microwave wireless power transfer (WPT) systems require highly efficient and compact power amplifiers (PAs).
• Existing PA designs often face challenges with integration level and efficiency.

Purpose of the Study:

• To design and fabricate a high-efficiency, compact power amplifier for microwave WPT systems.
• To meet the demands for high integration and efficiency in WPT applications.

Main Methods:

• Utilized a 0.25 μm Gallium Nitride (GaN) high electron mobility transistor (HEMT).
• Implemented an internally matched method for compact circuit size.
• Optimized output second and third harmonic impedances via output matching circuits.
• Controlled input third harmonic for improved DC-to-RF conversion efficiency.

Main Results:

• Achieved a compact power amplifier size of 13.4 × 13.5 mm².
• Demonstrated an output power of 43.75 dBm at 2.45 GHz under continuous wave (CW) testing.
• Measured a large-signal gain of 15.75 dB.
• Attained a power-added efficiency (PAE) of 78.5%.

Conclusions:

• The designed compact PA meets the requirements for high-efficiency microwave WPT systems.
• The internally matched method simplifies design and reduces size without compromising performance.
• The fabricated PA exhibits excellent output power, gain, and power-added efficiency.