微带传输线的无源互调效应实验研究

通过专用无源互调分析仪对微带传输线的无源互调（Passive Intermodulation,PIM）效应进行了初步实验研究. 在不同微波介质基材上设计并加工了特征阻抗为50 Ω的不同长度的微带传输线，通过专用无源互调分析仪进行PIM测试. 实验结果表明：输入载波功率每增加1 dB，三阶PIM产物功率增加约2.7 dB；三阶PIM产物有随载波频率增加而减小的趋势；微带传输线越长，则PIM产物功率越大；微波介质材料对PIM产物也有一定影响. 所得实验规律对高性能微波集成电路设计具有借鉴意义.

Experimental research on passive intermodulation effect of microstrip lines

In this paper, a preliminary experimental research on passive intermodulation (PIM) effect of microstrip lines is conducted using customized PIM analyzer. First, various microstrip lines of 50Ω characteristic impedance with different lengths are designed and fabricated on microwave dielectrics. Then, the microstrip lines are connected to the PIM analyzer through low PIM silver plated N type coaxial connector and their PIM products are measured. Measurement results show that the 3rd PIM products increases about 2.7 dB when input carrier increases 1 dB; PIM products tend to decrease with increasing carrier frequency; PIM products increases with the length of microstrip lines; microwave dielectrics also has notable effect on PIM products. The obtained results can provide reference for design of high performance microwave integrated circuits.