Theory of the suspended graphene varactor

We report the theory and design equations of the suspended graphene varactor, wherein device capacitance is tuned by the voltage controlled deflection of a suspended graphene membrane. A simple model based on large membrane deflection predicts a capacitor tuning range of 76%, with a membrane pull-in voltage tuneable from 1 V to 30 V. An intrinsic electric quality factor approaching 200 is predicted based on experimentally determined Young's modulus and sheet resistance.