N-Way Distributed Doherty Amplifier with an Extended Efficiency Range

This paper presents a novel 3-way distributed Doherty power amplifier with an extended efficiency range for WCDMA repeater or base-station applications. This distributed Doherty amplifier consists of one main amplifier and two peaking amplifiers. In order to get high efficiency at a high back-off power, the peaking amplifier structure is based on the dual-fed distributed amplifier form. The 2140 MHz measured results of the 3-way distributed Doherty amplifier yielded 11 dB power gain, with 39.5 % power added efficiency (PAE) at 9.5 dB backoff power. High linearity performance of -54 dBc ACPR is achieved after using memory compensated digital predistortion.