MEMS Series Switch with Nanometer Wide Gaps in Suspended Coplanar Waveguide Transmission Lines

A MEMS switch with sub-micron wide air gaps, milled into suspended center conductors of CPW transmission lines using focused ion beam milling, is introduced. The gaps were milled at an angle to produce two independent overlapping and electro-statically actuated cantilevers. By applying a voltage to the upper electrode, the gap ( ~ 0.1 mum) can be closed to provide a signal path in the series switch. When the bias is applied to the lower electrode, the isolation can be increased. An insertion loss of less than 1 dB and isolation greater than 20 dB were measured from 1 to 23 GHz