Design of Highly-Efficient Dual-Band GaN HEMT Power Amplifier With Dual-Class E/F−1 Operation

A novel methodology for designing high-efficiency dual-band (DB) power amplifier (PA) with a packaged transistor is presented in this paper. Specifically, a transmission lines-implemented load network is deployed to exhibit a composite operation with class E mode for low frequency and inverse class F (class F−1) mode for high frequency, which can overcome the difficulty of DB harmonic manipulation in class F−1 mode and efficiency degradation at high frequency in class E mode. A Cree transistor and two widely-spaced frequencies of 1.4 GHz and 3.5 GHz are selected for verification. The measured results show that saturation drain efficiency (DE) is 79.3% and 70.2%, corresponding to peak power added efficiency (PAE) of 77.4% and 62.9%, output power of 38.2 dBm and 37 dBm, and gain of 14.2 dB and 9 dB at 1.37 GHz and 3.48 GHz, respectively.