A UWB Frequency-Band Reconfigurable Antenna Using Switchable Slotted Ground Structure

In this paper, a novel compact ultrawideband (UWB) frequency-band reconfigurable antenna with seven switchable states including an ultra wideband (UWB) state , three narrowband states, one dual-band state and one triple band state is presented. In ultrawide band (UWB) state, antenna yields an impedance bandwidth of 2.54 to 11.71 GHz with return loss S₁₁ <; -10 dB. In case of three narrowband states, antenna operate over impedance bandwidth of 2.34 to 2.74 GHz, 3.71 to 3.97 GHz, 12.32 to 14.32 GHz with return loss S₁₁ <; -10 dB. In case of dual band state, antenna operate over impedance bandwidth of 2.34 to 2.74 GHz & 3.73 to 3.96 GHz with return loss S₁₁ <; -10 dB. In case of single triple band state antenna operate over impedance bandwidth of 2.47 to 2.66 GHz & 3.94 to 4.24 GHz & 6.97 to 7.42 GHz with return loss S₁₁ <; -10 dB. The designed antenna has a simple structure and compact size of 40 × 40 mm². In the proposed antenna, frequency-band reconfigurable capability is achieved by using a switchable slotted structure on the ground plane. For switching purpose, p-i-n diodes are used, which are placed at the slotted structure on the ground plane. The designed antenna is supporting most applicable frequency bands above 2 GHz, which can be used in multiband radio wireless systems. Moreover, the designed antenna has a combined UWB and narrowband functionality, which has a good potential for use in military applications and cognitive radio.