A Dual-band Outphasing Power Amplifier

In this paper, a novel dual-band outphasing power amplifier is proposed. Complying the load modulation principle of the Chireix outphasing PA, the quarter-wavelength impedance inverter in the classical structure is replaced with a dual-band impedance inverter. Besides, a new dual-band reactance compensation network configuration is devised to mitigate the intrinsic reactive loadings of sub-amplifier at two distinct frequencies. For demonstration, a dual-band (2.6 GHz and 3.5 GHz) PA prototype intended for LTE and 5G applications is realized using two 10-W GaN HEMTs. A maximum power of 44.6 dBm and 43.5 dBm is obtained at saturation with over 64% drain efficiencies. At 6-dB output back-off points, the corresponding efficiencies reach 58.4% and 50.1%, respectively.