(0.1～1.8)GHz SiGe HBT超宽带低噪声放大电路设计

本文选用SiGe材料低噪声放大芯片，设计了一款(0.1~1.8)GHz小型低功耗超宽带低噪声放大器（LNA）。该LNA采用两级放大结构，负反馈方式实现宽带匹配，级间和输出端匹配采用小阻值电阻提高电路稳定性，电路尺寸为35mm×15mm。测试结果表明：工作频率为(0.1~1.8)GHz，在室温条件下，增益为30dB，噪声系数<0.82dB，增益平坦度<0.5dB，输入输出回波损耗<-10dB，直流功耗为41.8mW；在-40℃低温条件下，增益为32dB，增益平坦度、输入输出回波损耗、直流功耗与室温下一致，噪声系数<0.69dB。设计过程与测试结果验证了本文中使用室温SiGe放大管的S参数计算-40℃温度下该芯片S参数方法的可行性。

Design of (0.1~1.8)GHz SiGe HBT Ultra Broadband Low Noise Amplifier Circuit

In this paper,a small low-power ultra-wideband Low Noise Amplifier(LNA)that can work at(0.1~1.8)GHz was designed with chip of SiGe material.The LNA adopts the structure of two-stage amplifier and negative feedback method to achieve broadband matching.The resistor of small value was used to improve circuit stability.The size of LNA was 35mm×15mm.The measured results showed that when the LNA was working at room temperature,the operating frequency was(0.1~1.8)GHz,the gain reached 30dB,the noise figure was less than 0.82dB,the gain flatness was less than 0.5dB,the input and output return losses were less than -10dB,and the DC power consumption of the circuit was 41.8mW.When the LNA was working at the temperature of -40℃,the gain reached 32dB,the flatness of the gain and the input and output return losses were basically unchanged,and the noise figure was lower than 0.69dB.The feasibility of method proposed in the paper to calculate S parameters of SiGe amplifier at the temperature of -40℃ was verified.