一种基于偶极子近场耦合法测量无源互调的方法

A Passive Intermodulation Measuring Method Based on the Coupling of Dipole Near-field

无源互调(PIM,Passive Intermodulation)是影响微波通信系统可靠性的关键问题之一。该文提出并实现一种利用近场耦合原理诊断接触结构待测件的PIM测量方法。该测量方法通过缝隙波导激励开口缝隙附近的接触结构,并同时在波导端面接收所产生的PIM信号,从而能方便地对不同物理接触状态的接触结构的PIM产物进行测试分析。并应用电磁商业仿真软件CST对PIM测试工装进行仿真验证,结果与基于偶极子的理论分析结论一致。最后利用铝合金接触结构开展了实验验证研究,获得了三、五阶PIM产物随载波功率的变化特性,实验验证了三阶和五阶PIM产物之差随载波功率降低而增大的变化规律。

Passive intermodulation （PIM, Passive Intermodulation） is one of the main problems in the reliability of microwave eonmmnieation systems. In this paper, a novel PIM test diagnostic method of metallic contact structure DUT （Device Under Test） using near-field coupling theory is proposed and implemented. Using this method, the PIM test system can stimulate the DUT near the slot as well as receive the PIM signal produced by the DUT. Thus, the PIM product of metallic contact structure DUT for the different contact situation can be tested and analyzed conveniently. Using a magnetic dipole model, the operation principle of the diagnostic method is analyzed. The CST simulation results of the designed configuration are consistent with the theoretical analysis based on the magnetic dipole model. The variation characteristics of 3rd and 5th order PIM product with cartier power are obtained by the PIM test experiment of the aluminum contact structure DUT and the theoretical explanation for the difference between 3rd and 5th PIM products with cartier power is also presented. This PIM diagnostic method for contact junction has potential application in the PIM scientific research as well as PIM engineering.