Research And Design Of High Linearity RF Driver Amplifier

With the development of society,development and applications such as telemedicine,webcasting,smart industry,and the Internet of Things have brought new opportunities and challenges to mobile networks.Fundamentally eliminate the contradiction between the people's growing data demand for the mobile Internet and the limited data processing capabilities of communication equipment.The best way is to use broadband high-frequency signals for mobile communications,which naturally promotes the rapid development of 5G communications.Usually the drive amplifier with high gain,high linearity,and good standing wave coefficient is used as the front stage of the power amplifier,and the low-power signal in the system is pre-amplified before driving the final power amplifier,so as to ensure that the final power amplifier output is sufficient High power.In a communication system,a driver with high linearity can reduce signal distortion at the same output power,so it is of great practical significance to design a gain module with high linearity,large bandwidth,high power,and excellent stability.First of all,this article describes the transistor technology of different materials and different working characteristics,and then introduces some basic theories of amplifiers,and carries out a detailed analysis of different circuit architectures in combination with theories.Using different circuit architectures,two Sub-6G driver amplifiers based on Ga As HBT technology for different applications are designed.One of them is a high-power medium-gain amplifier with high linearity requirements for base station communications.Next,a driver amplifier with high gain,wide frequency band,low power consumption and excellent linearity for mobile radio terminals was designed.In order to meet the gain requirement,a Darlington composite tube is selected as the amplifying circuit.At the same time,in order to overcome the instability of the static operating point of the traditional bias circuit,an adaptive active bias circuit with low environmental sensitivity is designed and optimized.The circuit schematic diagram is designed,simulated and optimized through simulating software ADS,and finally the layout EM simulation is performed and taped out for verification.The actual test results of the chip show that both amplifiers can meet the design specifications.The output P1 dB of the high linearity amplifier is above 26 dBm,the output OIP3 is above 40 dBm,and the standing wave coefficient is less than 2.The output OIP3 of the high-gain amplifier is above 29.5dBm,and the full-band gain is greater than 19 dB.According to the test results under high and low temperature environments,the active bias circuit used in this design plays a significant role.Through the design of the two amplifiers,we realized that the design of the radio frequency circuit also satisfies the analog octagon rule,and how to balance the performance indicators is very important.