Novel Broadband Doherty Power Amplifier Design for Multiband Handset Applications

In this paper, novel broadband Doherty power amplifier design for multiband handset applications, which requires only two components for output network, is proposed. Based on simplified output network, the proposed Doherty power amplifier is analyzed. The proposed Doherty power amplifier is demonstrated experimentally with InGaP-HBT. A PAE of 45.3% and an E-UTRA ACLR of -36.1 dBc at an average output power of 27.5 dBm are measured at 800 MHz under LTE 10 MHz, QPSK, 12 RB operation, and the efficiency improvement from Class AB operation achieves 12%. Moreover, the proposed Doherty power amplifier maintains more than 41.2% efficiency with an E-UTRA ACLR of below -35.5 dBc from 700 MHz to 950 MHz, corresponding to 30% fractional bandwidth.