An SOI bulk-micromachined dual SPDT RF-MEMS switch by layer-wise separation design of waveguide and switching mechanism

A compact monolithic RF-MEMS switch (2mm × 4mm in area) with the dual single-pole-double-throw (SPDT) configuration was developed by using the SOI bulk micromachining technique. The electrostatic comb-drive actuators and the mechanically movable coplanar waveguides were implemented on the low-resistive active SOI layer and the high-resistive handle layer, respectively, to effectively allocate the device footprint. Electrical crosstalk between the waveguide and the electrostatic actuator was suppressed by using the buried silicon dioxide layer. At a driving voltage of 35V, the switch exhibits an insertion loss of 3dB and isolation of 30dB at 12GHz.