In this article, a frequency reconfigurable antenna using the ON/OFF states of a MEMS (micro‐electro‐mechanical system) switch is presented. This structure is based on a planar inverted‐F antenna (PIFA), designed with an L‐shaped open slot etched upon its main plate. According to the switch position along the slot, the GSM operating frequency is not detuned while other standards become reconfigurable. To validate our concept, a RF MEMS switch, designed and developed at CEA‐LETI, is used. The scattering parameters of the MEMS are measured and compared with simulated results from a simple model using lumped elements and transmission line sections. This active device is then inserted in the slot to validate the switching capabilities of the PIFA.