D. L. Bohin - Postgraduate Student of Moscow Aviation Institute, Department of Radiophysics, Antennas and Microwave Technique. E-mail: xendgal@gmail.com

The bow-tie radiator (see fig. 1) is taken as a prototype antenna. In this paper, three modifications are proposed, numerically optimized and studied using Finite Elements Method-based software. The first is a quadrature-fed combination of two bow-tie structures above the screen (fig. 3), it has 8 dB fails in antenna pattern (fig. 4), which is considered as unacceptable. The second one has inclined wings (fig. 5), so wings' ends together with the screen plane form slotline radiating add-on to the bow-tie. This antenna's pattern is much more homogeneous with 1,2 dB fails (fig. 9). The SWR <2 bandwidth is 9.4 %. The third structure has their wings aligned on a spherical surface as it is shown in fig. 10. Its bandwidth is increased up to 26 %. The input impedance curves on fig. 2, 7 and 8 are normalized to 50 Ohm.