Novel digital double-input three-path Doherty power amplifier device

Abstract

The invention discloses a novel digital double-input three-path Doherty power amplifier device, comprising a power divider and a second peak power amplifier, wherein the power divider is used to divide a first input signal into two equal power or unequal power, and one signal output end of the power divider is connected with the signal input end of a carrier power amplifier through a first phase compensation line or in a direct mode to form a power amplifier branch; one signal output end of the power divider is connected with the signal input end of a first peak power amplifier through a second phase compensation line or in a direct mode, and the signal output end of the peak power amplifier is connected with a first impedance compensation line to form a power amplifier branch; the second peak power amplifier receives a second input signal, and the signal output end of the second peak power amplifier is connected with a second impedance compensation line to form a power amplifier branch; and the three power amplifier branches are serially connected with a load impedance conversion circuit after parallel connection, wherein the phase and amplitude of two input signals can be adjusted. Compared with a traditional asymmetrical two-path Doherty power amplifier, the problem of efficiency recession in output power back-off intervals can be improved, and thus the average efficiency of the power amplifier can be greatly increased.

Description

technical field [0001] The invention belongs to the field of power amplifier design, in particular to a novel digital double-input three-way Doherty power amplifier. Background technique [0002] For the increasing demand for communication bandwidth and communication speed, complex modulation techniques are usually adopted in wireless communication systems to improve spectrum utilization. Due to the use of high-order modulation modes containing amplitude modulation, wireless communication signals usually have higher peak than (Peak to Average Power Ratio, PAPR). This feature requires that the power amplifier must work in a certain output power back-off area, while traditional power amplifiers often have good linearity when they work in the output power back-off area, but their drain efficiency is very low. In order to solve this problem, Many technologies such as outphasing technology (Outphasing), envelope tracking technology (Envelope Tracking, ET) and Doherty technology ...

AI Technical Summary

Problems solved by technology

Although the asymmetrical Doherty power amplifier can achieve a large power backoff, the current ratio of the peak power amplifier to the carrier power amplifier also increases with the backoff, and the saturated output power of the peak power amplifier will be far greater than the carrier power. The output power of the power amplifier is saturated, and the efficiency of the drain stage is very low during the period when the peak power amplifier is just turned on, so this will cause the average efficiency of the overall Doherty power amplifier to decrease during the period when the peak power amplifier is just turned on

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