A Dual-Band High Efficiency Class-F GaN HEMT Power Amplifier for Wireless Communication

A class-F high-efficiency GaN power amplifier (PA) for concurrent dual-band operation at 1.84 and 3.5 GHz frequencies is proposed. A novel dual-band bandpass filter with 4-sections stepped impedance resonators (SIRs), which rejects the annoying frequencies of the second and third harmonics in the dual-band and contributes greatly to efficiency improvement of PA. The proposed 4-sections SIR filter has the harmonic rejection of more than 20/26.7 dB in 1.84/3.5 GHz, respectively, which is sufficient for rejecting harmonics, and insertion loss of less 0.2 dB. The experimental results show that output power of 40 dBm and 11 dB of gain at the two bands were obtained. The maximum power added efficiency (PAE) are obtained 75% at 1.84 GHz and 68.4% at 3.5 GHz frequencies. Linearity results using 10-MHz 16-QAM signal at 1.84 GHz and a 10-MHz WiMAX signal at 3.5 GHz, show an adjacent channel leakage ratio (ACLR) of -46.6 and -42.3 dBc with the average output power of 37.6 and 36.1 dBm at 1.84 and 3.5 GHz, respectively.