封闭式桅杆内的电磁干扰试验研究

针对所设计的一种封闭式射频集成桅杆，首先测试桅杆内部两个天线一发一收状态下接收天线射频端口的信号电平，从而判断是否会受到发射天线的电磁干扰。与传统的单纯观察设备的后端显示部分来进行干扰判断不同，射频信号测试与电子设备的后端信号处理能力无关，通过定量评估耦合能量的大小，进而可以总结通用的封闭桅杆的电磁干扰规律。试验结果表明，在封闭桅杆内同层、同面且上下布置的两副板阵天线间存在谐波干扰现象。然后，通过对天线特性、复合带通滤波层板特性、测试数据和桅杆内的电磁干扰路径进行大量、详细的理论分析来判断干扰来源。最终发现，电磁干扰很大程度上是由封闭桅杆内部发射天线的谐波通过天线边缘单元的直接辐射及内壁反射从而耦合到接收天线所造成，这是由于桅杆的封闭特性导致天线发射的带外能量无法射出，从而造成内部设备之间的电磁干扰。最后，针对此现象提出电磁干扰的一些控制措施，例如天线间敷设吸波材料、天线分层布置等。

Experimental Study on the Electromagnetic Interference in the Integrated Mast

In this paper, an integrated mast is designed, and the signal of radio frequency at the emission port of the receiving antenna is measured to analyze the electromagnetic interference phenomena. Different to estimating the interference from displaying equipment, the actual data collected for electromagnetic cou-pling power can be used to conclude the universal rule in the integrated mast as the signal power of radio frequency is independent from the processing ability of the equipment. According to the experiment results, the phenomenon of electromagnetic interference has been found between two array antennas laid in a plane on the same deck inside the integrated mast. By analyzing the characteristic of the two antennas, the com-posite band-pass filter plate, the experiment data, and the interference path, it has been noticed that the in-terference signal is coupled with the near-field antenna＇s harmonic by direct transmission or reflection through the mast wall. Generally, the integrated mast keeps the electromagnetic power within, and such property engenders the above-mentioned electromagnetic interference between equipment. Finally, some measurements regarding the electromagnetic interference control in the integrated mast are presented, in-cluding switching to radar signal absorbing materials and arranging antennas in different decks.