HIGHLY RELIABLE WIDEBAND SWITCHED MEMS CAPACITORS
T. VÄHÄ-HEIKKILÄ, M. YLÖNEN

Abstract. A wideband switched MEMS capacitor has been developed based on CMOS compatible surface micromachining. It has a capacitance ratio of 1:3-1:5 between its up- and down-states depending on the applied bias voltage. The measurement results show that the switched capacitor has good microwave performance (S11 better than –28 dB up to 40 GHz with S21 better than 0.5 dB in the up-state). Very good reliability has been demonstrated by hot switching (18 dBm at 26 GHz) the component 50 million times with 10 Hz switching frequency (50% duty cycle) which results in totally more than 1 000 hour downstate time. This corresponds tens of billions cycles if kilohertz switching frequency is used. The component was fully functional after the test.