Fast Prediction Method for PIM Distribution on Waveguide Temperature Compensation Structure Using DC Non-Linearity Diagnosis

This paper proposes a fast prediction method for PIM distribution in the waveguide resonator with temperature compensation (TC) structure. When faced with temperature changes, the waveguide filters expand or contract, affecting the size-dependent resonant frequency. Therefore, filters with high selectivity necessitate temperature compensation structures to ensure thermal stability under stringent circumstances, especially in space applications. Structural connections and contacts always exist in the TC structures, serving as typical sources of passive intermodulation (PIM). When compensation appears, the mechanical deformation accompanying thermal stress will complicate the PIM analysis. DC non-linearity diagnosis is applied in this proposed method, which can fast predict the PIM distribution in TC structures without the PIM test. This prediction method can significantly cut off the testing cost and attain high efficiency in PIM analysis.