Role of dielectric layer and beam membrane in improving the performance of capacitive RF MEMS switches for Ka-band applications

Abstract

In this paper, we have analyzed the role of dielectric layer and different beam membranes on the performance parameters of shunt capacitive RF MEMS switch. The investigation mainly focused on the major challenges of performance parameters are reducing actuating voltage and improving the isolation. The actuation voltage is reduced by incorporation of non-uniform meanders to the serpentine membrane structure and also improved the isolation using 50 nm AlN dielectric thin film. Here, we have incorporated the holes to the top membrane which help the switch to improve the insertion property. The actuation voltage required to move the switch downwards is 5.4 V and the switch operates at transition time of 12 μs. The isolation − 72.4 dB is observed at the frequency of 27 GHz and insertion − 0.34 dB is observed at the frequency of 27 GHz. The characteristics of switch have been observed by simulating the switch design in FEM tool and results have been compared with theoretical calculations. Finally, the switch is optimized based on the switch performance parameters and it is suitable for Ka-band applications.