Pre-distorted radio frequency amplifier

Abstract

The invention discloses a pre-distorted radio frequency amplifier, comprising a first power amplifier, a second power amplifier, a first coupler, a second coupler, a pre-distorted unit and a first quadrature bridge. The first power amplifier carries out power amplification on an initial carrier signal to form an amplified signal; the first quadrature bridge combines the amplified signal with a amplified pre-distorted signal to offset an intermodulation signal to form a combined signal; the first coupler is arranged in front of the first power amplifier to couple the input initial carrier signal; the second coupler is coupled with the combined signal; the pre-distorted unit combines the initial carrier signal from the first coupler and the combined signal from the second coupler to offset to form a pre-distorted signal including the initial carrier signal and the intermodulation signal; and the second power amplifier is used for carrying out the power amplification equivalent to the first power amplifier on the pre-distorted signal to form the amplified pre-distorted signal. The invention realizes higher working bandwidth and working efficiency and can be applied to different working environments.

Description

【Technical field】 [0001] The invention relates to the field of power amplifiers in modern mobile communication systems, in particular to a predistortion radio frequency amplifier. 【technical background】 [0002] For a long time, the efficiency improvement technology and the linearization technology of the power amplifier used in the communication system have been the research hotspots in the industry. [0003] Due to the adoption of various non-constant envelope modulation methods (such as QPSK, QAM, OFDM, etc.), modern wireless communication systems have greatly improved the utilization of frequency resources. , 2.5G, 3G, 4G, LTE) are growing rapidly, and the downlink in the system requires high-efficiency, high-linearity, multi-carrier power amplifiers to amplify to meet the needs of base stations (remote radio frequency unit RRU, repeater, indoor coverage system etc.) coverage requirements of the device. [0004] As is known, the linearization technology of power amplif...

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Problems solved by technology

[0005] Since the non-constant envelope signal of the modulation technology will cause the power amplifier to produce large nonlinear characteristics, the multi-carrier power amplifier conventionally adopts the feed-forward (FF) technology architecture, although it has excellent cancellation performance, wide operating bandwidth, and multi-standard However, due to factors such as high technical complexity, low efficiency, and high cost, its development is restricted

[0006] Due to the influence of factors such as narrow working bandwidth and poor cancellation effect, analog predistortion technologies such as envelope tracking cannot work in the case of multi-carrier

[0007] Digital predistortion technology is a promising linearization technology, which has the cha

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