A Segmented Polynomial Model to Evaluate Passive Intermodulation Products From Low-Order PIM Measurements

In this letter, a segmented polynomial model is developed to accurately calculate the powers of high-order passive intermodulation (PIM) products from the measurement data of low-order PIM product. This proposed model fully considers the dependence of dominant PIM generation mechanism on carrier power. An example of a microstrip transmission line is given to verify the effectiveness of this model, and excellent agreement between the measured data and calculated results has been achieved. Compared to the common-used polynomial model, not only the order adopted in the segmented model is much lower but also the number of measured data required for evaluation is much less. Moreover, this presented model can calculate the more accurate high-order PIM products than any other model. Thus, it can provide a theoretical guidance for PIM performance assessment in engineering application.