This paper presents the design of improved MEMS shunt switch for RF communication applications. The switch was designed to provide a better performance in 10-100 GHz range. The switch was optimized in terms of width of the beam and air gap between the fixed type beam and dielectric layer to improve the isolation, insertion, and return loss. This study concludes that materials with high k-dielectrics and high Young's modulus are desirable for better performance in highfrequency range. The isolation, insertion, and return loss for the designed switch are obtained as -12 dB, -0.05 dB, and -45 dB, respectively.