A Concurrent 2.45/5.8 GHz Power Amplifier with an Optimal Dual-band Matching Method

This study presents the design and fabrication of a concurrent 2.45/5.8 GHz dual-band power amplifier (PA) with a dual-band matching method for optimized performance. The proposed matching method simultaneously utilizes series and parallel resonance to transform the frequency-dependent fundamental complex optimum load impedance to $50 \Omega$ at two arbitrary frequencies. Additionally, the selectable range of a low-frequency is analyzed when a high-frequency is selected. The dual-band PA was designed and fabricated on the Rogers 5880 substrate, utilizing the Wolfspeed GaN HEMT CGH40006s. Measurement results indicate that the implemented dual-band PA achieves a small signal gain of 13.9 dB at 2.45 GHz and 10.6 dB at 5.8 GHz. Furthermore, at the 3 dB compression point, the output power (OP$_{3dB})$ is measured at 38.4 dBm for 2.45 GHz and 38.6 dBm for 5.8 GHz, while the corresponding drain efficiency (DE$_{3dB})$ is 71 % at 2.45 GHz and 59.6 % at 5.8 GHz. OP$_{3dB}$ and DE$_{3dB}$frequency responses of the dual-band PA were above 38 dBm and 70 % between 2.4 GHz and 2.5 GHz, and over 38 dBm and 55 % from 5.7 GHz to 5.9 GHz, respectively.