Doherty Power Amplifier Distortion Correction Using an RF Linearization Amplifier

Independently Tunable Linearizer Based on Characteristic Self-Compensation of Amplitude and Phase

“…2 can be fitted to a power series for ease of calculation. Using (6) and (7), the derivative factor of phase and amplitude can be calculated, respectively. Fig.…”

“…In [6], a power-scalable wideband linearization technique by parallelly adding a linearization amplifier (LA) at the output of the main PA is proposed, using this method, a good performance and a wide working bandwidth of more than 160 MHz are achieved at 0.85 GHz, the power consumption reduces from several watts of conventional DPD system to 1.6 W of the LA under the same linearity. Then the same method is used to linearize a Doherty PA, and it makes a good performance too in [7]. However, the proposed topology of [6], [7] is extremely sensitive to the time delay between main PA and LA, it is a challenge for the design and control of the system, and it limits the LA's bandwidth.…”

“…Then the same method is used to linearize a Doherty PA, and it makes a good performance too in [7]. However, the proposed topology of [6], [7] is extremely sensitive to the time delay between main PA and LA, it is a challenge for the design and control of the system, and it limits the LA's bandwidth. A transistor based linearizer is proposed which composed of a linear PA and an error PA in [8], but the addition of two transistors increases the power consumption and cost of the entire system.…”