Doherty power amplifier capable of improving power back-off dynamic range and realization method thereof

Abstract

The invention provides a Doherty power amplifier capable of improving a power back-off dynamic range and a realization method thereof. The Doherty power amplifier comprises an equal Wilkinson power divider, a carrier power amplification circuit, a peak power amplification circuit, and a novel load modulation network, wherein the equal Wilkinson power divider is used for equally dividing an input power and then outputting the equally-divided input power to the carrier power amplification circuit and the peak power amplification circuit; and the output end of the carrier power amplification circuit is connected with an 86.6 ohm quarter wave-length impedance transformer T1, and is connected with the output end of the peak power amplification circuit and the power is combined to be outputted to the load. Compared with the prior art, the load modulation network of the traditional Doherty power amplifier is improved, and thus, the load impedance of a main power amplifier in a low-input power state is enhanced, and the high-efficiency power back-off range of the Doherty power amplifier is improved.

Description

technical field [0001] The invention relates to the technical field of radio frequency communication, in particular to a Doherty power amplifier for improving the dynamic range of power back-off and a realization method thereof. Background technique [0002] With the rapid development of wireless communication technology, radio frequency microwave technology is becoming more and more important in people's daily life. In order to transmit as much data as possible within a limited spectrum bandwidth, communication providers usually use very complex modulation methods, which will lead to a larger peak-to-average ratio (PAPR) of the signal, while using traditional power amplifiers such as class A, Class AB is very inefficient for amplifying non-constant envelope signals, especially at high power backoffs. The RF power amplifier with high efficiency and high linearity has become one of the research hotspots in academia and industry. Doherty power amplifiers have become the main...

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Problems solved by technology

[0004] In order to increase the power fallback range of Doherty power amplifiers, communication providers generally use asymmetric transistors, that is, the peak power amplifier uses a tube with a larger power capacity, and at the same time uses an unequal power divider at the input end to improve the power fallback range, but this introduces new problems, such as reduced overall Doherty amplifier gain, reduced power utilization factor, etc., especially at low input power

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