This book presents the design, fabrication and measurements of stress tolerant RF MEMS switches with high power handling and reliability. RF MEMS switched capacitors are developed that are capable of handling >10 W of RF power under hot switching conditions. SPST (single-pole single-throw) and SP4T (single-pole four-throw) RF MEMS metal-contact switches with high power handling and reliability have also been developed. The design is based on circular cantilevers that are anchored at the center and are attached together using a radial arc. This provides a compact SPST switch with multiple contact points and can easily be transformed to SPNT by dividing the membrane into several cantilevers each with its own actuation electrode. A power handling of > 10 W and > 2 W with high reliability has been measured for the SPST and SP4T switches, and with high reliability. Furthermore the design of temperature resilient RF MEMS capacitive switches with the capacitance ratio of >30 have been achieved. The switch is used as a building block of different circuit configurations such as SPST, SPDT and a 2-bit X-band phase shifter with good performance.