Linear transmitter using non-linear element

Abstract

The present invention provides a linear transmitter which adopts non-linear components. The transmitter comprises a digital signal processing unit, an analog signal processing unit, a signal amplification unit, a synthesis unit, and a feedback unit. The digital signal processing unit is used for pre-processing the input signals of the transmitter; the analog signal processing unit is used for transforming digital baseband signals into analog baseband signals, and directly transmitting the signals to the transmission carrier frequency through quadrature modulation; the signal amplification unit adopts a high-efficiency non-linear power amplifier to amplify the radio frequency signals; the synthesis unit is used for synthesizing and transmitting outwards the two types of signals; the feedback unit is used for coupling and processing the transmission signals so as to acquire the out-of-band power value of the transmission signals; wherein, the digital signal processing unit can complete the separation and pre-distortion processing of the input signals, calculating the gain and phase error of the two branches, controlling the gain and the phase of one branch so that the two branches maintain the consistent amplitude and phase, and thus guaranteeing that the transmitter has high linearity and high efficiency.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a linear transmitter using nonlinear components. Background technique [0002] With the development of wireless communication technology, in order to improve the frequency band utilization, more complex and efficient modulation methods are adopted. This puts higher demands on the transmitter, especially the power amplifier in it. The efficiency and linearity of the power amplifier are key factors to be considered in practical applications. Reducing power consumption while improving linearity has become a research hotspot of power amplifiers. [0003] In recent years, with the development of digital signal processing technology, the linear amplification technology LINC (Linear Amplification With Nonlinear Component) using nonlinear components has received more and more attention. The structure of a traditional LINC transmitter is as follows figure 1 shown. A signal sepa...

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Problems solved by technology

If the gain and phase of the two branches are unbalanced, the efficiency and linearity index of the whole system will be deteriorated

Moreover, the efficiency of the entire system is determined by the efficiency of the power amplifier and the efficiency of the synthesizer. Although the power amplifier has a high operating efficiency, the efficiency of the synthesizer is closely related to the peak-to-average ratio of the signal. For the input signal with a peak-to-average ratio, The combining efficiency of the LINC transmitter combiner will be low, limiting the efficiency of the overall transmitter

Therefore, it is difficult for conventional LINC transmitters to maintain high efficiency over a large range of power levels

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