An X- to ku-band 3-bit digital MEMS varactor

A 3-bit digital microelectromechanical system (MEMS) varactor bank is demonstrated on a low-cost glass substrate. It is composed of three discrete-position varactors, each of them achieving a capacitance ratio close to 3:1. The total capacitance of the varactor bank is tunable from 146 fF to 430 fF in eight states and is suitable for X- or Ku-band operation. The design can be easily scaled to Ka-band frequencies.