Study On Performance Improvement Of The PIM Test System At Ku Band

Now, since more and more antenna system of the satellite payloads transmit and receive signals with the same community antenna, the power of the microwave passive components increases gradually. This will result in the passive intermodulation (PIM) which is harmful to the modern high-power multi-channel satellite. If this problem could be found by the PIM test at the passive component level and the whole satellite level and resolved ultimately in the test period before launching of the satellite, the phenomenon of PIM of the satellite at the orbit satellite will be greatly reduced, so that the normally working of the satellite could be guaranteed.Aimed at the test of the PIM problem, several test methods based on the analysis of the source of the PIM were introduced in this thesis firstly. Then, an improvement in performances of the test system in Ku-band used now in the application was proposed. The results show that contact nonlinearity in the connector of the test system could be reduced effectively through the high pressure flange structure which increased the pressure on the flange of the waveguide, therefore, the PIM of the test system was decreased. Finally, the uncertainty analysis was done on the improved test system. The main contents of this thesis are as following:The structure of the test system in Ku-band was introduced and several test methods were proposed. The methods include:the reflected PIM test, the radiation PIM test, the reradiation PIM test and system level PIM test. The method of the system calibration in the PIM test was also proposed.According to the situation in the practical application in engineering, an improved scheme on the high pressure flange of the waveguide of the test system was proposed in the existing test system in Ku-band. This improvement enhanced the performance of the test system in the PIM test. Finally, the uncertainty analysis of the test system was done and the validity of the improvement was verified by experiments.This thesis provides some theoretical and practical basis for the PIM test, and presents a practical test scheme for the manufacture of the passive devices and the third-party laboratory.