摘要
为了解决微弱信号检测过程中的输入噪声匹配问题,文章根据低噪声放大器的噪声匹配特点设计了一种自适应阻抗匹配网络模型;该模型通过实时测算信号源阻抗和低噪声放大器最佳源阻抗的变化自动调整匹配网络的相关参数,从而达到输入阻抗匹配的目的;仿真实验结果表明,此模型在一定程度上能较为准确地实现低噪声放大器的噪声匹配,稳定性较好,解决了微弱信号检测中因源阻抗的变化引起的放大器噪声系数恶化、检测灵敏度下降等问题,具有一定的工程应用意义。
In order to solve the problem of inputting noise match during detecting weak noise, an self -adaptive impedance matching network module was designed based on the noise matching characteristics of I.NA. By measuring and computing the change of source imped anee and the optimum impedance of LNA simultaneously, the module can adapt relative parameters of matching network automatically, and consequently achieve the aim of impedance match. Simulation experiment has shown that, the module can realize the impedance match of LNA with well stability and solve problems, such as deterioration of amplifier NF and detection sensitive, caused by changes of source impedance in weak signal detection. It＇s useful in engineering applying.
出处
《计算机测量与控制》
CSCD
北大核心
2009年第3期543-544,551,共3页
Computer Measurement &Control
基金
湖北省自然科学基金项目(CGZ0696)
关键词
低噪声放大器
自适应阻抗匹配网络
微弱信号检测
low noise amplifier （LNA）
self-adaptive impedance matching network
weak signal detection
