在某多功能单元级数字阵列阵面系统进行接收波瓣测试时,发现法线附近出现了10 dB 左右的噪声鼓包,当波束指向偏离法向1°~2°时,出现噪声鼓包消失的噪声扫瓣现象。文中从接收级联噪声系数基本模型出发,推导出多通道输入接收系统噪声系数公式,并对接收内部的附加噪声注入的来源和对系统的作用进行了分析和数学建模,并定义了附加噪声扫描角优化因子概念,合理地解释了噪声扫瓣现象。进一步地,根据数学模型提出了多种解决方案,并分析了现有条件下各种方案的优缺点,最终选择了降低注入噪声功率的措施,实践证明基于该措施的解决途径有效。文中的机理分析、数学模型、解决方案对后续产品有指导作用,对实际工程应用具有很高的参考价值。

When the receiving lobe is tested in a multi-function unit-level digital array system, it is found that there is a noise drum packet about 10dB near the normal. The phenomenon of noise sweeping lies that the noise drum packet disappears when the beam points from one degree to two degrees away from the normal direction. In this paper, based on the basic model of cascaded noise figure of receiver, the noise figure formula of multi-channel input receiving system is derived, and the source of additional noise injection inside the receiver and its effect on the system are analyzed and mathematically modeled, the concept of optimization factor of additional noise scanning angle is defined, and the phenomenon of noise sweep is explained reasonably. Furthermore, according to the mathematical model, a variety of solutions are proposed, and the advantages and disadvantages of various schemes under the existing conditions are analyzed, and finally the measures to reduce the injection noise power are selected. The practice shows that the solution based on this measure is effective. The mechanism analysis, mathematical model and solution in this article can guide the follow-up products and have high reference value for practical engineering applications.

TN958