A miniature 8–16 GHz packaged tunable frequency and bandwidth RF MEMS filter

This paper presents a packaged two-pole ultra-miniature RF MEMS tunable filter for 8-16 GHz applications. The filter is fabricated on a quartz substrate using lumped-element design techniques, and results in independent tuning of the center frequency and bandwidth over the entire frequency range. This is achieved using 4-bit and 3-bit RF MEMS capacitors in the resonators and the inverters, respectively. Every RF MEMS switch in the filter (20 different switches) is packaged using a localized in-situ dielectric cap technique, and therefore, the filter does not need any special handling. To our knowledge, this is the first large-scale package of a tunable RF MEMS component to-date. The measured results indicate that the filter response can be tuned from 8-16 GHz and that the loss is limited by the lumped-element inductor Q and bias line resistance.