Research On 5G Millimeter Wave Linearization Amplifier

Modern communication technology is developing rapidly.In order to improve the communication speed and frequency utilization rate,various complex modulation techniques are applied to the communication system.These modulation signals have a high peak-to-average ratio.At the radio frequency end,the power amplifier is the core of the radio frequency system.When the amplifier processes these peak-to-average ratio signals,it often adopts a back-off work method in exchange for a lower efficiency in exchange for higher linearity.Improving the linearity of the amplifier while maintaining high efficiency is the focus of current research.This article mainly studies the linearization technology of the amplifier based on analog predistortion.The main research contents of this article are as follows:1.This article introduces the linearization technology of the amplifier,analyzes the analog predistortion technology based on the device in detail,and thoroughly studies the principle of Schottky diode analog predistortion and the cold mode pHEMT analog predistortion.2.This paper proposes an improved predistortion structure based on the existing analog predistortion technology structure combined with reflective predistortion technology,and the working of the structure is derived and analyzed.In addition,the structure was simulated and verified on the simulation platform ADS,the simulation results show that the structure can significantly improve the linearity of the amplifier.3.This paper has designed a series of power amplifier chips and completed the Ka band three amplifiers,which verifie the function of the analog predistorter.These three chips are respectively without predistortion module,with cold-mold predistorter,with the improvement type predistorter.The linearity index IMD3 of the three amplifiers are compared.When fallback from saturation power is 5dB,the IMD3 with a cold-mode predistortion module is improved by 10 ~ 15 dBc and the improved bandwidth is about 2GHz.the improvement type analog predistortion improved about 15 dBc,and the improved bandwidth is about 3GHz.So the improvement type analog predistortion module can meet the design requirements and improve the non-linear characteristics of the amplifier.