应用于航天器的低无源互调滤波器分析

随着航天器有效载荷朝着大功率、小型化方向发展，大功率滤波器的无源互调问题成为制约航天器有效载荷发展的重要问题。对应用于航天器的大功率同轴滤波器产生无源互调的因素进行了研究，发现了表面镀层处理和不同材料调节螺钉方式对无源互调的影响规律。用介质隔离同轴连接器内导体和馈电杆的接触方式，设计了一种S频段低无源互调同轴滤波器，比传统同轴滤波器的无源互调有效降低了20dB。这表明该方法是一种有效降低大功率微波部件无源互调的方法，可应用于航天大功率和地面移动通信大功率微波部件。

Analysis of low passive intermodulation filter used in spacecraft

With the development of spacecraft payloads toward high power and miniaturization, the problem of passive intermodulation (PIM) of high power filters has become an important issue that restricts the development of spacecraft payloads. The factors of generating passive intermodulation in high power coaxial filter used in spacecraft were researched and explored which found the influence rules on passive intermodulation of different surface coating treatments and adjusting ways of screws by different materials. In this paper, a S-band low-passive intermodulation coaxial filter was designed according to the contact made between the inner conductor and the feeding pole of the dielectric isolated coaxial connector. Compared with the traditional coaxial filter,the passive intermodulation of the new one can be effectively reduced by 20dB. This shows that the method is effective to reduce the passive intermodulation of high power microwave components and can be used in high power microwave and ground mobile power components.