Ultrawideband Antenna With Triple Band-Notched Characteristics Using Closed-Loop Ring Resonators

The design of a simple multilayered triple band-notched ultrawideband (UWB) antenna is presented in this letter. The proposed antenna is compact in size, suitable for ultrawideband applications, and exhibits triple narrow frequency band notches to suppress the interference of the nearby wireless communication systems within a UWB frequency range. The narrow band notches are realized by adding closed-loop ring resonators designed to cover the 3.3-3.7-GHz, 5.15-5.35-GHz, and 5.725-5.825-GHz bands. The center frequencies of the band notches can be adjusted by varying the ring resonators' mean diameters. The designed antenna has a compact volume of 33 × 30 × 1.524 mm 3 . The antenna is fabricated and tested providing broadband impedance matching, appropriate gain, and stable radiation pattern.