High-fallback Doherty power amplifier based on asymmetric structure and implementation method of high-fallback Doherty power amplifier

Abstract

The invention provides a high-fallback Doherty power amplifier based on an asymmetric structure and an implementation method of the high-fallback Doherty power amplifier. The high-fallback Doherty power amplifier adopts an asymmetric power divider used for dividing input power unequally and outputting a first signal of relatively low power to a main power amplifying circuit and a second signal of relatively high power to an auxiliary power amplifying circuit; a 50-ohm quarter-wave impedance transformer T1 is connected to the output end of the main power amplifying circuit and is connected with the output end of the auxiliary power amplifying circuit; and a 28.9-ohm quarter-wave impedance transformer T2 is connected in series to the joint end of the 50-ohm quarter-wave impedance transformer T1 and the auxiliary power amplifying circuit, so that power is combined and then output to a load. Compared with the prior art, due to the adoption of the asymmetric structure and improvement on a load modulation network of the conventional Doherty power amplifier, the load impedance of a main power amplifier in a low input power state is increased, and the high efficiency power fallback 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 an asymmetric structure-based high back-off Doherty power amplifier 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 mainstream f...

AI Technical Summary

Problems solved by technology

For example, the peak-to-average ratio in the TD‐SCDMA system can reach 10dB. If so, the efficiency of the traditional Doherty power amplifier with a fallback of 6dB will be greatly reduced. Therefore, in today's world that advocates energy conservation, environmental protection, and green communications, improving the fallback efficiency of the power amplifier will be has great practical significance

Images