A switchable planar monopole antenna operating in ultra-wide band and dual band mode is demonstrated. The switching is triggered with a photoconductive semiconductor switch triggered by light emitting diode. In the switched-off state, the antenna operates in the dual-band/UWB mode, while in the switch-on state the configuration converts to a dual band antenna due to the extended ground plane. The measured and simulated results show that the dual-band/UWB mode entirely covers the UWB frequency band and the 2.4 GHz wireless local area network WLAN, while the dual band mode represents a dual band antenna operating at WiMax and X-band Satellite communication bands.