A MEMS capacitive switch suitable for use in tunable RF amplifiers is described. A MEMS switch is designed, fabricated, and characterized with physical and RF measurements for inclusion in simulations. Using the MEMS switch models, a dual-band low-noise amplifier (LNA) operating at 2.4 GHz and 5.2 GHz, and a tunable power amplifier (PA) at 5.2 GHz are simulated in 0.18 μm CMOS. MEMS switches allow the LNA to operate with 11 dB of isolation between the two bands while maintaining 11.6 dB of gain and sub-4.5 dB noise figure. MEMS switches are used to implement a variable matching network that allows the PA to realize up to 37% PAE improvement at low input powers.