Design and Implementation of a High-Efficiency 250W Power Amplifier for RF Heating Applications

This study presents the design, implementation, and performance analysis of a 250 W power amplifier (PA) with a 14 dB gain, operating at a center frequency of 2450 MHz for RF heating applications. The amplifier utilizes a CGH21240F GaN HEMT transistor mounted on an RT5870 substrate, with carefully designed input and output matching circuits. These matching networks were optimized using load-pull and source-pull analyses to maximize both output power and efficiency. Simulation results indicated that the output power exceeding 54 dBm and a power-added efficiency (PAE) above 64%. Upon fabricating the circuit with precision assembly on a milled printed circuit board, experimental measurements confirmed the simulated performance, achieving an output power of 54 dBm and a PAE over 63%. Harmonic analysis demonstrated effective suppression of higher-order harmonics, confirming the amplifier's ability to deliver high-power output with minimal distortion.