An asymmetric doherty power amplifier with extended bandwidth and its realization method

Abstract

The present invention provides an asymmetrical Doherty power amplifier with extended bandwidth and its implementation method. An asymmetrical power divider is used to divide the input power unequally, and output the first signal with smaller power to the main power amplifying circuit. And the second signal with larger power is output to the auxiliary power amplifying circuit; the output end of the main power amplifying circuit is connected with one end of the impedance converter T1, and the output end of the auxiliary power amplifying circuit is connected with the second impedance converter T2 One end is connected, the other end of the second impedance transformer T2 is connected to one end of the third impedance transformer T3, the other end of the impedance transformer T1 is connected to the other end of the third impedance transformer T3, and is jointly connected with the load connected at one end. By adopting the technical scheme of the invention, the Doherty power amplifier can still maintain high efficiency when the power backs off by 9dB, and at the same time increase the working bandwidth of the asymmetrical Doherty power amplifier.

Description

technical field [0001] The invention relates to the technical field of radio frequency communication, in particular to an asymmetrical Doherty power amplifier with extended bandwidth 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 form ...

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

[0004] In addition, the Doherty power amplifier with asymmetric structure will also have the common problem of the traditional Doherty power amplifier-the problem of narrow bandwidth

Because the load modulation network of the Doherty power amplifier with asymmetric structure still adopts the common 50 ohm quarter-wavelength impedance converter in the prior art, this leads to a relatively large impedance conversion, thus greatly limiting the bandwidth

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