A Capacitive Shunt RF MEMS Switch for Coplanar Waveguide Transmission Lines

Bengt HOLTER¹, Karsten HUSBY¹, Håkon SAGBERG², Geir U. JENSEN², Ulrik HANKE³, Shimul CHANDRA SAHA⁴, Trond SÆTHER<sup>4

1</sup>SINTEF ICT, Communication Systems, O.S. Bragstads plass 2C, Trondheim, Norway, Phone: +47 73593000
²SINTEF ICT, Microsystems and Nanotechnology, Gaustadalleen 23, 0373 Oslo, Norway, Phone: +47 22067300
³Vestfold University College, Microsystem Technology, 3103 Tønsberg, Norway, Phone: +47 33031000
⁴Norwegian University of Science and Technology, 7491 Trondheim, Norway, Phone: +47 73595000

Abstract. In this paper, performance results are presented for the first RF MEMS switch ever to be produced in Norway. It is a shunt capacitive switch integrated in a coplanar waveguide configuration. The switch uses a bipolar (square wave) bias voltage for both actuation and holddown, and is designed to operate in the frequency range 10-32GHz. The fabrication process has been developed and performed at the Micro and Nano Laboratory at SINTEF, which has the only independent complete silicon processing line in Norway. In the targeted frequency range (10-32GHz), the measured insertion loss is between -0.17 and -0.4dB, the return loss between -23 and -12dB, and the isolation is between 7.5 and 20dB. The achieved capacitance ratio of the switch is 25. Some stiction problems have been observed for either a too high pull-in voltage or a too high hold-down voltage.