High-isolation BST-MEMS switches

In this paper, emerging (Ba,Sr)TiO/sub 3/ thin film technology was investigated for enhancing RF-MEMS capacitive switches. Materials properties of high-permittivity BST thin films and fabrication issues are discussed. Prototype BST-MEMS switches for K-/Ka-band applications were fabricated and measured. This measured data is compared with measurements from conventional SiN-based MEMS switches, showing improved isolation at lower frequencies due to the higher down-state capacitance density.