RF analysis of MEMS shunt capacitive switch with gold and aluminium beam

Abstract

In a practical MEMS switch, there is a gap between the beam and the signals lines. Based on this, a study on frequency response starting from dc to radio frequency for Gold and Aluminium is carried out. Study reveals that the pull-in voltage and capacitance ratio for Gold are 13.8 V and 88.3, respectively; while for Aluminium these values are 11.4 V and 82.4, respectively. Also a detailed study of variation of insertion loss with frequency is also carried out. The insertion and isolation losses with gold as beam layer are -1.42 and 40.4 dB, respectively, at radio frequency, while the same losses for Aluminium as beam layer are -1.19 and 36.1 dB, respectively at the same frequency.