A Broadband Ohmic RF MEMS Switch

A broadband electrostatic-driven direct-contact series MEMS switch is present,composed of a coplanar waveguide(CPW)line,two folded U-shape cantilevers,two metal contact pins and one anchor.To improve the switch's reliability,the mechanical parameters are optimized for fine ohmic contact,no stiction between the beam and the actuation electrodes and low-actuation voltage.The switch,which has 3 ports,is fabricated on 400 μm-thick silicon substrate by low temperature metal-dielectric surface micromachining process.And its chip size is 0.8 mm×0.9 mm.The measured intrinsic loss of the switch is 0.1 dB(equivalent resistance Rs=0.6 Ω)and the measured isolation is 24.8 dB(off-state capacitor Cu=6.4 fF)at 6 GHz.The switch exhibits good mechanical properties with switching time of 47 μs and wide actuation voltage of 20-60 V.