Analysis of uniform structured RF MEMS switch with different uniform and non-uniform meandering techniques

Abstract

This paper mainly focuses on the investigation of different meandering techniques for the MEMS RF shunt capacitive switch. It involves three meandering techniques for the switch, namely zig-zag, plus and three square meander. Actuating beam provided with rectangular holes, with these parameters switches brings about low pull-in voltage, higher switching speed, good performance of isolation, less spring constant, low insertion and return losses. In addition, from obtained results, it is noted that the rectangular holes give the better outcomes, when contrasted with square and cylindrical perforations present on the beam. All the meandering techniques are applied for the movable bridge; improved performance is observed by comparing these structures, by changing the gap between the electrodes of each structure. Another criteria is gap, performance observed for different air gaps 0.8, 1 µm between top and bottom electrode. Materials used for the dielectric layer are HfO2 and Si3N4. ON state capacitance for HfO2, Si3N4 are 4.07, 3.81 fF. Similarly, OFF state capacitance for the two dielectric materials are 49, 26.9 fF respectively. Poly tetra fluoro ethylene (PTFE) is the material utilized for the deflecting beam. Pull-in voltages for the step switch with three square meanders are 1.09 V at 0.8 µm gap. RF performance analysis of the step switch with three square is attained as insertion loss is below − 0.07 dB, return loss was observed below − 60 dB over the frequency range of 1–40 GHz frequency range. Isolation peak noted at 61 dB at 28 GHz frequency. Switching time of the step switch with three square meander are 10.25 µs.