Analog predistortion based linear power amplification circuit and method

Abstract

The invention discloses a linear power amplification circuit based on the simulation of predistortion, comprising a predistortion amplifier, a first temperature-controlled attenuator, a simulate predistorter, a second temperature-controlled attenuator, a push-pull amplifier, and a last stage high-power amplifier which are sequentially connected. The invention also discloses a method to use the circuit: the simulate predistorter circuit which has relatively simple topological structure is added to produce a distortion signal of a predistortion signal balanced power amplifier; a matching circuit and a bias voltage of a power tube of the push-pull amplifier and that of the last stage high-power amplifier are adjusted to make the two power tubes complement in amplitude and phase to achieve the predistortion effect and to enable better linearity of the RF output signal. The invention is simple in circuit structure, high in working efficiency, low in cost and occupies little PCB area, which is extremely suitable for the multi-carrier linear power amplification circuits in the TD-SCDMA stations and the repeaters 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] Figure 1 shows the basic principle of analog pre-distortion technology: when a non-constant envelope signal is amplified by a high-power amplifier with a small power margin, the part with a higher peak value will have an amplitude due to the nonlinear saturation of the high-power amplifier Distortion (AM-AM) and phase distortion (AM-PM), which lead to deviations in the amplitude and phase of the output vector signal, and at the same time cause spectrum expansion and interfere with adjacent channel signals

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