A 80W high gain and broadband Doherty power amplifier for 4/5G wireless communication systems

摘要

This paper presents a 80W high gain and broadband Doherty power amplifier (DPA) with symmetrical devices, employing Wolfspeed's CGHV27030S GaN HEMT. A novel architecture is used to eliminate the complex interaction of varying second harmonic impedances caused by active load modulation and provide high efficiency at output back-off (OBO) region and saturation point. Under a 10% duty cycle pulse excitation from 3.35-3.50 GHz, experimental results show the proposed DPA delivers 49.1-49.5 dBm output power with a drain efficiency (DE) of 50.2%-55.1% at 8 dB OBO and achieves a gain of 14.6-14.9 dB at an output power of 41 dBm. When extend the bandwidth to 3.3-3.6 GHz, the DPA can attain a measured DE higher than 40.9% at an OBO of 8 dB with a saturated power of 48.5-49.5 dBm. For a 2-carrier 40-MHz long-term evolution (LTE) signal with a peak-to-average power ratio (PAPR) of 8 dB, the adjacent channel leakage ratio (ACLR) is -30 dBc at 41 dBm average output power at 3.45 GHz.