摘要
接收机的非线性是影响雷达系统性能提高的一个很重要的因素 .整个雷达接收系统是由放大器、滤波器及混频器等多级模块构成的 ;每一级模块都在一定程度上存在着非线性失真 ,从而在接收机的输出端产生由交调和互调干扰而导致的虚假信号 ,给信号检测和识别带来很大困难 .通过严格的理论分析 ,论述了三阶截点与三阶互调这两个线性度指标之间的相互关系 ,给出了三阶截点的合理测试方法 ,研究了多级模块构成的接收系统中 ,系统三阶截点与各模块的三阶截点、增益以及接收机各级的选择性等指标间的相互制约关系 .在推导得出的级联公式的基础上 ,给出了如何通过合理地设计各级模块的三阶截点。
The nonlinearity of receiver is an important element to limit the improvement of the performance of radar system. The whole radar receiving system consists of many modules such as amplifiers, filters and mixers. Non linearity exists in each module to some extent. Therefore pseudo signals resulted from cross modulation and inter modulation emerge at the output of the receiver and bring about difficulty for signal detection and identification. The relationship between third order intercept point and third order intermodulation is detailed. Reasonable measurement of third order intercept point is brought forth and the relationship between the whole system and each module in multi module receiving system is derived based on rigorous theoretical analysis. According to the deduced cascading equation, how to improve the third order on channel and off channel intercept point of the receiving system is put forward by reasonably designing the third order intercept point of each module.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2002年第4期566-569,共4页
Journal of Harbin Institute of Technology