Abstract
Passive intermodulation (PIM) is a niggling phenomenon that debilitates the performance of modern communications and navigation systems. PIM products interfere with information signals and cause their nonlinear distortion. The sources and basic mechanisms of PIM have been studied in the literature but PIM remains a serious problem of signal integrity. In this paper, the main sources and mechanisms of PIM generation by joints of good conductors are discussed. It is shown that the passive electrical, thermal and mechanical nonlinearities are intrinsically linked despite their distinctively different time scales. The roughness of the contact surfaces plays an important role in PIM generation by conductor joints. A review of the PIM phenomenology at the contacts of the good conductors suggests that novel multiphysics models are necessary for the analysis and reliable prediction of PIM products generated by several concurrent nonlinearities of a diverse physical nature.
Highlights
The continuously growing volume and speed of data transmission pose major challenges to existing and future wireless and satellite communications and navigation systems [1–7]
The ET–passive intermodulation (PIM) generated by joints of rough surfaces is related to their effective contact resistance Ru defined in (3) and depends on the effective size aeff of a contact area and an averaged contact resistivity ρav that increases with temperature as defined by (5)
The discussed physical mechanisms are cast in the three main groups of (i) electrical, (ii) thermal and (iii) me
Summary
The continuously growing volume and speed of data transmission pose major challenges to existing and future wireless and satellite communications and navigation systems [1–7]. The lumped element model, proposed in [54], has been applied to the analysis of PIM in waveguide flanges where the physical dimensions of surface asperities are much smaller than the wavelengths of high-power RF signals The parameters of this equivalent circuit depend on the electrical properties of the contact materials and on their thermal and mechanical properties and the surface finish. Charge tunnelling and diffusion at MIM junctions of conductor asperities; Current constriction at asperities of rough contact surfaces; Self-heating and thermal expansion of the contact surfaces and asperities; Electro-thermal effect due to ohmic losses in conductors and contacts; Asperity deformations of the conductors with rough surfaces and their contacts subjected to mechanical stresses, expansion and creep These nonlinearities exist in conductor joints concurrently and influence each other despite their notably different time scales.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
