Nonlinearity Modeling of Contact-Type RF MEMS Switch Based on Passive Intermodulation Analysis
This paper presents a nonlinearity model of contact-type RF MEMS switch based on passive intermodulation (PIM) analysis. Both distributed PIM source on transmission line and lumped PIM source on contacts are considered. Finite element analysis softwares (HFSS and ePhysics) and Holm’s theory are introduced to analyse the heat effect and PIM of the switch. The analysis results show that the contact resistance variation is the major influence for nonlinearity of the contact-type RF MEMS switch. The theoretical value of IIP3 of the device ranges from 75 to 95 dBm for 0.5–2.5 Ω per contact under the situation of 1 MHz envelope frequency. And the use of metal with low electrical resistivity (ρ) can result in high linearity significantly.