Gain enhancement of the Vivaldi antenna with band notch characteristics using zero-index metamaterial

In this letter, a tapered slot ultrawide band (UWB) Vivaldi antenna with enhanced gain having band notch characteristics in the WLAN/WiMAX band is presented. In this framework, a reference tapered slot Vivaldi antenna is first designed for UWB operation that is, 3.1-10.6 GHz using the standard procedure. The band-notch operation at 4.8 GHz is achieved with the help of especially designed complementary split ring resonator (CSRR) cell placed near the excitation point of the antenna. Further, the gain of the designed antenna is enhanced substantially with the help of anisotropic zero index metamaterial (AZIM) cells, which are optimized and positioned on the substrate in a particular fashion. In order to check the novelty of the design procedure, three distinct Vivaldi structures are fabricated and tested. Experimental data show quite good agreement with the simulated results. As the proposed antenna can minimize the electromagnetic interference (EMI) caused by the IEEE 802.11 WLAN/WiMAX standards, it can be used more efficiently in the UWB frequency band. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:233-238, 2016