S波段宽带低噪声放大器的设计

摘要

微波宽带低噪声放大器是雷达、电子对抗、微波通信及遥测遥控等接收系统的关键部件.为满足高性能微波接收机系统对微波低噪声放大器宽频带、低噪声系数、高增益和好平坦度等方面的要求.本文利用Infineon公司的BFP740FESD型双极晶体管,采用纯电抗宽带匹配技术,设计了一个2~4 GHz宽带低噪声放大器(LNA).经过实际测试,该放大器在2~4 GHz频带内,功率增益大于30 dB,噪声系数小于1.8 dB,增益平坦度小于3 dB,输入输出驻波比小于2,输出饱和功率大于5 dBm,且工作绝对稳定.%Microwave broadband low noise amplifier plays an important role in the receiver system of radar, electron countermeasures, microwave communication,remote measuring and remote control, and so on. A high performance microwave receiver system have a higher request for low noise amplifier featuring broadband, low noise figure, high gain, and flat response.In order to meet the requirements a 2~4GHzbroadband low noise amplifier (LNA) was designed with pure reactance broadband matching technology by using the Infineon's BFP740FESD bipolar transistor.Test result of LNA shown thatoverall frequency of 2~4 GHzgain is largerthan 30 dB, noise figure is less than 1.8 dB,gain flatnessis less than 3 dB, input and output SWRs are less than 2.To characterize linearity,output saturation power is greater than 5dBm and the amplifier has a stable performance.