Design and Analysis of MEMS Shunt Capacitive Switch with Si3N4 Dielectric and Au Beam Material to Improve Actuation Voltage and RF Performance in Consideration With and Without Circular Perforations

Abstract

This paper presents the design of a MEMS shunt capacitive switch with fixed–fixed beam for high frequency RF applications. The switch dimensions were very carefully chosen to obtain the optimum performance of the switch when actuated with RF transmission line. The designed switch uses two different structures: beam without perforations and beam with circular perforations with same switch dimensions. Spring constant of the switch with perforations shows reduction in requirement of actuation voltage due to significant reduction in spring constant. Actuation voltage analysis was also done for two structures and the actuation voltage for switch with perforations found to be 6.80 V which is 35.23% less compare to switch without perforations (10.5 V). RF characteristics in terms of Insertion loss, return loss and isolation found to be − 0.05 dB, − 43 dB and − 12 dB without perforations and it was − 0.03 dB, − 48 dB and − 15.5 dB for the switch with perforations at 62 GHz frequency. The switch designed with circular perforations shows improvement in insertion loss, return loss and isolation by 20%, 15% and 24% respectively compare to switch without perforations. The switch can be used for V-band applications like satellite communications and RF applications.