Design and Simulation of an Oblique Suspender MEMS Variable Capacitor

This paper presents the results on the development of a novel micromachined parallel plate tunable capacitor with a wide tuning range. Different from conventional parallel plate capacitors, this novel tunable capacitor consists of one suspended top plate, suspending with four oblique arms and one bottom fixed plate. These oblique arms increase the length of the cantilevers, in order to cause more deflection and, hence, increase the tuning range of the capacitor for constant bias voltage. Applying a DC voltage between two plates provides electrostatic actuation for capacitance tuning. According to electromagnetic simulation, a tuning range of 146% has been achieved with a 1.7 volt bias voltage. An empirical behavioral model is extracted from simulated y parameters of the structure.