A Frequency-Reconfigurable Monopole Antenna Using Switchable Slotted Ground Structure

In this letter, a novel compact frequency-reconfigurable monopole antenna with five switchable states including an ultrawideband (UWB) state, three narrowband states, and a dual-band state is presented. The frequency-reconfigurable capability of the antenna is achieved by using a switchable slotted structure on the ground plane. The designed antenna has a simple structure and compact size of 40×40 mm . The antenna, which supports most applicable frequency bands above 2 GHz, can be used in multiradio wireless systems. Moreover, the proposed antenna, which has a combined UWB and narrowband functionality, has a good potential for use in cognitive radio.