Broadband Doherty Power Amplifier with Enhanced-Efficiency

A novel method to design enhanced efficiency Doherty power amplifier is presented in wide-frequency range. Dual impedance matching network technique is adopted to achieve impendence match while the power amplifier works at saturated region and 6dB back-off region. Besides, post-matching structure is employed as the substitute of classic λ/4 impedance transformation line. Thanks to eliminate the conventional λ/4 impedance converter, a broadband Doherty power amplifier prototype is accomplished with a frequency range of 1.8-2.6GHz . The measured output power of proposed amplifier is 44.4-45.2dBm, the power gain is 9.4-11.1dB, the saturated drain efficiency is 63.5-84%, and the 6dB back-off efficiency is 55.1-61%. The measured results verify the proposed method well.