Improved Frequency Notched Ultrawideband Slot Antenna Using Square Ring Resonator

An improved frequency notched ultrawideband (UWB) microstrip slot antenna with a square ring resonator embedded in the tuning stub is proposed. The antenna is investigated numerically and experimentally for its impedance matching property, frequency notched characteristic and radiation performance in detail. As will be reported, compared with conventional frequency notched slot antennas, after incorporating a square ring resonator with the slot antenna's tuning stub, high, sharp band-rejection characteristic of over 20 dB is achieved, which is improved significantly.