High-Q continuously tunable zipping varactors with large tuning range

The design, simulation and fabrication of high-Q zipping MEMS varactors is presented. A novel, stable zipping design allows continuous tuning as well as a large tuning range. High quality factors can be obtained using gold electrodes in order to minimise series resistance. By incorporating a high-permittivity dielectric in the varactor, the tuning range can be greatly increased and at the same time, the device size can be reduced. A fabrication process has been developed, including pre-stressed layers to provide the initial curvature, and this has been demonstrated up to and including transfer and bonding of the top electrodes from a carrier wafer.