级联电路的En-In噪声性能分析

本文从级联电路的Ｅｎ－Ｉｎ噪声模型出发，分析了Ｆｒｉｉｓ定量的局生，并描述了级联电路Ｅｎ－Ｉｎ噪声的数学模型，模型形式简捷，参数提取方便，便于移植到电路噪声仿真程序中，文中不报前置级联电路的最小噪声条件，由于充分考虑了Ｅｎ与Ｉｎ噪 提的相关性，从而有效地保证了级联电路噪声计算的精度。

级联电路的En-In噪声性能分析

Based on the En-In noise model of cascade circuits, not only the limitation of Friis theorem is analysed,but also the En-ln noise mathematical model for the cascade cireuits is developed. This model with simple formulas and easy parameter's extraction will facilitate the implementation of the model into the simulation programs for the circuit noise. The analsis also focuses on the minimum noise conditions for the cascade precucuits. Because the correlativity between the En and In is considered, the pnyision of noise calculation for the cascade circuits can be guaranteed effectively.