A Novel Design of Reconfigurable Slot Antenna With Switchable Band Notch and Multiresonance Functions for UWB Applications

A novel printed reconfigurable square slot antenna with switchable band-notched and multiresonance performances is designed and manufactured. In the proposed structure, in order to generate single band-notched characteristics, a Π-shaped slot is etched on the radiating stub. Furthermore, to achieve a reconfigurable function, a p-i-n diode is utilized across the slot. When this p-i-n diode is biased forwardly, the Π -shaped slot transforms to a pair of C-shaped slots, and also by changing to this new structure, an additional resonance is excited. Additionally, by cutting two modified L-shaped slits with variable dimensions on the microstrip feed line, new additional resonance is excited, and hence wider impedance bandwidth can be produced, especially at the higher band. The designed antenna has a small size of 20 × 20 mm² while showing the radiation performance in the frequency band of 3.04 to over 11.17 GHz with a switchable band-rejection performance in the frequency band of 5.03-5.94 GHz. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the ultrawideband (UWB) frequency range and also it has a reconfigurable frequency band-notched function in the range of 5-6 GHz that can eliminate the interference between UWB frequency band and other existing wireless communication systems.