Design of Experiment Analysis on Multiple PIM Sources in an RF Antenna System

Passive intermodulation (PIM) has been identified as one of the common root causes for receiving sensitivity degradation (desense) on radio-frequency (RF) antennas working in frequency-division duplex mode. The component-level PIM characterization and simulation have been well-established over the years. However, the study has been using an ideal 50 Ω transmission line system while antenna modules are more complicated than a simple transmission line structure. Moreover, the metallic contacts can exist in multiple locations with different connection topologies in real applications. This paper provides a method to simulate the PIM performance caused by the metallic contacts in a practical environment. In addition, the design of experiment (DoE) analysis is conducted to understand the statistical relationship between the component nonlinearity and the total PIM levels. Prioritizing the critical contact locations design insights including what-if scenario studies are found with the DoE.