exception of the removal of the sacrificial spacer, which requires critical point drying, the fabrication steps are similar to CMOS fabrication process steps. RF MEMS fabrication processes, unlike BST or PZT ferroelectric and MMIC fabrication processes, do not require electron beam lithography, MBE, or MOCVD. Reliability Contact interface degradation poses a reliability issue for ohmic cantilever RF MEMS switches, whereas dielectric charging beam stiction, as shown in Fig. 5(a), and humidity induced beam stiction, as shown in Fig. 5(b), pose a reliability issue for capacitive fixed-fixed beam RF MEMS switches. Stiction is the inability of the beam to release after removal of the drive voltage. A high contact pressure assures a low-ohmic contact or alleviates dielectric charging induced beam stiction. Commercially available ohmic cantilever RF MEMS switches and capacitive fixed-fixed beam RF MEMS switches have demonstrated lifetimes in excess of 100 billion cycles at 100 mW of RF input power. Reliability issues pertaining to high-power operation are discussed in the limiter section. Applications RF MEMS resonators are applied in filters and reference oscillators. RF MEMS switches, switched capacitors and varactors are applied in electronically scanned (sub)arrays (phase shifters) and software-defined radios (reconfigurable antennas, tunable band-pass filters). Antennas Polarization and radiation pattern reconfigurability, and frequency tunability, are usually achieved by incorporation of III-V semiconductor components, such as SPST switches or varactor diodes. However, these components can be readily replaced by RF MEMS switches and varactors in order to take advantage of the low insertion loss and high Q factor offered by RF MEMS technology. In addition, RF MEMS components can be integrated monolithically on low-loss dielectric substrates, such as borosilicate glass, fused silica or LCP, whereas III-V compound semi-insulating and passivated silicon substrates are generally lossier and have a higher dielectric constant. A low loss tangent and low dielectric constant are of importance for the efficiency and the bandwidth of the antenna. The prior art includes an RF MEMS frequency tunable fractal antenna for the 0.1–6 GHz frequency range, and the actual integration of RF MEMS switches on a self-similar Sierpinski gasket antenna to increase its number of resonant frequencies, extending its range to 8 GHz, 14 GHz and 25 GHz, an RF MEMS radiation pattern reconfigurable spiral antenna for 6 and 10 GHz, an RF MEMS radiation pattern reconfigurable spiral antenna for the 6–7 GHz frequency band based on packaged Radant MEMS SPST-RMSW100 switches, an RF MEMS multiband Sierpinski fractal