This paper studied the original model of the switch, which has a full-contact pull down voltage of 13.7V. And the RF results are measured firstly by Cascade 12000 microwave probe in order to calculate the parameter of the equivalent circuit. The equivalent circuit is built to study the RF performance and the s-parameters are studied by ADS. However, the high actuation voltage will degrade the switch life. Then four optimized geometric models are compared in order to obtain the lowest actuation voltage. Finally, the model of trapezium shape has the longest life span 1.452×106 and smallest full-contact down voltage 6.3V.