Abstract: Vivaldi antenna also known as end-fire tapered slot antenna (TSA) is a kind of tapered slot antenna works on the principle of travelling wave antennas having exponential tapered profile, which provide large bandwidth and end-fire radiation patterns with low profile is a good candidate. This single tapered slot end-fire vivaldi antenna (STSVA) possess low directivity. Hence there is a need to improve the directivity without altering the aperture space. This work proposes a novel structure of multi tapered slots of vivaldi antenna without altering the dimension of the aperture area which provided lower HPBW compared to STSVA. The multi-slot structure generates plane-like waves in the End fire direction. This further enhanced directivity of the multi-slot Vivaldi antenna. The simulated results show that impedance bandwidth of the multi tapered -slot Vivaldi antenna is from 2 to 18GHz.

Keywords: Multi tapered slots, Directivity, Half Power Beam Width (HPBW) and Aperture area.