Ultra-wide tuning range silicon MEMS capacitors on glass with Tera-ohm isolation and low parasitics

Theoretical and experimental results of a design methodology and fabrication technology to realize ultrawide tuning range, electrostatic, silicon micromachined capacitors are presented. The varactors achieve a maximum tuning range of approximately 4000% and exhibit a linear tuning range of 1000% (C vs. V/sup 2/). The devices are also designed and characterized with Tera-ohm isolation and sub 30 fF capacitive coupling between the driving actuator and tuning element. In addition, parasitic capacitances have been minimized to less than 22 fF at the tuning element terminals.