通信系统对无源器件的大量使用, 使无源互调级联问题越来越普遍。针对此问题, 建立了简单的无源器件两级级联模型。在TE10模式下, 用泰勒级数表征波导结处的金属-绝缘层-金属结构的非线性, 考虑了传输线长度对输入载波信号相位的影响, 分析了无源互调功率随传输线长度和输入载波相位差Δθ的变化情况。结果表明, 波导结两级级联时, 无源互调功率随输入载波信号相位的不同, 存在0~3 dB大小不同的累加值, 由相位差Δθ可以得到取得最大和最小累加值时的传输线相位长度; 且由于无源互调频率成分的相互作用, 波导中互调产物种类也急剧增加。

The use of a large number of passive devices in communication system makes passive intermodulation series connection problem becoming more and more common. In order to solve this problem, a simple model of two cascaded passive devices is established. In the mode of TE10, the nonlinear structure of metal-insulator-metal is characterized by Taylor series, where the effect of transmission line length on the input carrier signal phase is considered. We also analyze the variation of the passive intermodulation power with different length of transmission line and the input carrier phase difference Δθ. The results show that the passive intermodulation power is different with the phase of input carrier signal in the two stage of the waveguide junction, and the cumulative value is between 0 to 3 dB. In addition, the transmission line phase length at the maximum and minimum cumulative value can be obtained by the phase difference Δθ. Due to the interaction among the passive intermodulation frequency components, the intermodulation product types increase dramatically in waveguide.