A novel nonlinear model describing the passive intermodulation (PIM) behavior in coaxial connectors is developed based on sine function. Two types of coaxial connectors are selected as test samples, and a series of two-tone PIM tests are conducted. The coefficients of the sine function model for these connectors are obtained by fitting the test results using ordinary least squares (OLS) method. The predicted results of the sine function model agree well with the test results, which prove that the sine function model can be used to describe the third-order and the fifth-order PIM performance of coaxial connectors accurately. The differences between the sine function model and other nonlinear models are compared.

中文翻译：

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同轴连接器无源互调的新型非线性模型

基于正弦函数开发了一种描述同轴连接器中无源互调 (PIM) 行为的新型非线性模型。选取两种同轴连接器作为测试样品，进行一系列的双音PIM测试。这些连接器的正弦函数模型的系数是通过使用普通最小二乘法 (OLS) 方法拟合测试结果获得的。正弦函数模型的预测结果与测试结果吻合较好，证明正弦函数模型可以准确地描述同轴连接器的三阶和五阶无源互调性能。比较了正弦函数模型与其他非线性模型的区别。