Analog predistortion based linear power amplification circuit and method

Abstract

The invention discloses a linear power amplifying circuit based on analog predistortion, which comprises sequentially connected: a preamplifier, a first temperature-controlled attenuator, an analog predistorter, a second temperature-controlled attenuator, a push-pull amplifier, and a final stage high power amplifier. The invention also discloses a method using the circuit, by adding an analog predistorter circuit with a relatively simple topology to generate a predistortion signal to balance the distorted signal of the power amplifier, and by adjusting the power tube of the push-pull amplifier and the final high-power amplifier The matching circuit and bias voltage make the two power tubes complement each other in amplitude and phase to achieve the effect of pre-distortion, so that the RF output signal can achieve better linearity. The invention has the advantages of simple circuit form, high working efficiency, small occupied PCB area and low cost, and is very suitable for multi-carrier linear power amplifier circuits of TD-SCDMA base stations and repeater systems.

Description

technical field [0001] The invention relates to a power amplifying circuit, in particular to a linear power amplifying circuit based on analog predistortion. The invention also relates to a linear power amplification method using the circuit. Background technique [0002] With the rapid advancement of the industrialization process of the third generation (3G) mobile communication technology, especially the TD-SCDMA (Time Division Synchronous Code Division Multiple Access) standard, various wireless communication services continue to increase , the requirements for the capacity of the communication system are also increasing. In order to pursue higher data rate and spectral efficiency, the linear modulation method and multi-carrier technology commonly used in third-generation mobile communications will cause drastic changes in the signal envelope, which will cause peak compression and intermodulation distortion in the transmitting power amplifier. Such peak compression and ...

AI Technical Summary

Problems solved by technology

[0008] like figure 1 The basic principle of analog predistortion technology: when the non-constant envelope signal is amplified by a high power amplifier with a small power margin, the part with higher peak value will produce amplitude distortion due to the nonlinear saturation of the high power amplifier (AM -AM) and phase distortion (AM-PM), resulting in a deviation in the amplitude and phase of the output vector signal, and at the same time causing spectrum expansion and interference with adjacent channel signals

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