Realisation of radio frequency microelectromechanical devices for multiband, tunable circuit applications

In this work a microelectromechanical-based parallel plate variable capacitor, a micromachined-inductor and an LC resonator that is formed by combining these two are presented. The parallel plate variable capacitor has curvature due to compressive stress and this allows the theoretical 50% tuning range to be exceeded. By changing the tuning voltage from 0 to 55 V, the varactor can achieve capacitance values from 90 to 260 fF. Additionally, inductors are designed and fabricated using the same process steps. Inductance values of 1.5 to 2 nH and quality factors from 5 to 10 are achieved. An inductor and variable capacitor are combined to form an LC resonator whose centre frequency changes from 8.194 to 6.192 GHz with applied voltages from 0 to 30 V.