High-power and high-efficiency Doherty power amplifier

Abstract

The invention provides a high-power and high-efficiency Doherty power amplifier. The high-power and high-efficiency Doherty power amplifier comprises an unequal Wilkinson power divider, a carrier power amplification circuit, a peak power amplifier circuit and a load modulation network, wherein the carrier power amplification circuit adopts a continuous B / J class power amplifier, the peak power amplifier circuit adopts a two-level power amplifier cascade structure, an auxiliary peak power amplifier circuit adopts a C class power amplifier, and a main peak power amplifier circuit adopts a B / J class power amplifier. Compared with the prior art, the high-power and high-efficiency Doherty power amplifier adopts a new Doherty structure, and accordingly, the saturated output power can be greatly improved while the efficiency is guaranteed; an auxiliary peak power amplifier adopts an ordinary C class, a main peak power amplifier and a carrier power amplifier adopt an continuous B / J class, secondary short circuit and quartic short circuit as well as tertiary and quintic open circuit can be well controlled by means of a harmonic control network, a current waveform output by power amplifiers approximates a half-sine wave, a voltage waveform approximates a square wave, and the backspacing efficiency and the saturated output power of Doherty are greatly improved.

Description

technical field [0001] The invention relates to the technical field of radio frequency communication, in particular to a Doherty power amplifier with high power and high efficiency. Background technique [0002] In recent years, wireless communication technology has been greatly developed, and the modulation methods are becoming more and more complex. The power amplifier, as the final module in the transmitter, is the component with the largest power consumption in the entire radio frequency system. Its main function is to amplify the power of the signal output by the previous stage, and then send the amplified signal to the antenna for transmission. Due to the change of the transmission mechanism and the increase of the transmission distance, the ability of the power amplifier to output high enough power and have a high enough efficiency has become the main technical index pursued at present, and the linearity is also a key index of the power amplifier. This is mainly refl...

AI Technical Summary

Problems solved by technology

However, the peak power amplifier of the traditional Doherty power amplifier only contains one power amplifier, so the power contributed by the peak power amplifier in the entire Doherty is greatly restricted. large, but this parallel structure will lead to an increase in the overall area of ​​the power amplifier; in addition, in the Doherty power amplifier in the prior art, the carrier power amplifier is biased in the AB class operation mode, and the peak power amplifier is biased in the C class operation mode. Due to the traditional AB Class and Class C power amplifiers, resulting in the maximum saturation efficiency and fallback efficiency of Doherty power amplifiers cannot be further improved

At the same time, the current carrier power amplifier and peak power amplifier in the Doherty power amplifier only consider the fundamental wave matching and do not consider the improvement of the efficiency of the harmonic control. The focus of Doherty's research is how to improve the back-off efficiency and saturation output of the power amplifier. power

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